DEPABTMENT OF THE INTEBIOR

BULLETINS

OF THE

UNITED STATES

GEOLOGICAL SURVEY

VOL. VII

WASHINGTON

GOVERNMENT FEINTING OFFICE

1888

CONTENTS.

BULLETIN No. 42.

Report of work done in the Division of Chemistry and Physics, mainly during 

"the fiscal year 1885-'86 .................................................. 1

BULLETIN No. 43.

On the Tertiary and Cretaceous strata of the Tuscaloosa, Toinbigbee, and Alabama Rivers, by Eugene A. Smith and Lawrence C.Johnson .............. 152

BULLETIN No. 44. 

Bibliography of North American geology for 1886, by Nelson H. Darton........ 343

BULLETIN No. 45. 

The present condition of knowledge of the geology of Texas, by Robert T. Hill. 37i

BULLETIN No. 46.

The nature and origin of deposits of phosphate of lime, by R. A. F. Penrose, jr.,

with an introduction by N.S.Shaler..................................... 47£

in

ILLUSTRATIONS.

BULLETIN No. 42.

Page. 

PLATE I. Map of a portion of western Maine................................. 11

FIG. 1. Border of lepidolite on muscovite................................... 16

2. Portion of thin section of hydronephelite.......................... 32

3. Apparatus for determination of boric acid.......................... 68

4. Grand Rapids meteorite ........................................... 95

5. Etched surface of Grand Rapids meteorite ......................... 95

6. Etched surface of Aberfc meteorite................................. 96

7. Diagram showing variation of the density of steel, with temperature

of annealing .................................................... 101

8. Polarization figures of Prince Rupert drops........................ Ill

9. Polarization figures of successive cores of Prince Rupert drops...... 115

10. Diagram illustrating the relation of graphitic carbon and thermoelectric hardness to the hydro-electric position of steel............ 129

BULLETIN No. 43.

PLATE I. Claiborne Upper Lauding, Alabama River ........................ 155

11. St. Stephens Bluff, Tombigbee River .............................. 174

III. Claiborne between Upper and Lower Landings, Alabama River.... 180

IV. Coffeeville Landing, Toinbigbee River ............................ 184

V. Hatchetigbee upper end of bluff Tombigbee River.............. 192

VI. Wood's Bluff, looking down the river, Tombigbee River .. J........ 196

VII. Yellow Bluff Landing, Alabama River............................ 197

VIII. Nanafalia Landing, Tombigbee River ............................. 208

I.. GuHy in sauds of the Tuscaloosa formation, near Havana, Hale

County, Ala .................................................... 262

X. Exposure of Ripley strata near Moscow Landing, Tombigbee River. 284

XI. Outline map of Alabama showing the distribution of Cretaceous

and Tertiary strata.............................................. 286

XII. Sections of the White Limestone on Alabama and Tombigbee Rivers. 294

XIII. Sections of the Claiborne strata, Alabama and Tombigbee Rivers.. 298

XIV. Sections of the Buhrstone strata.................................. 302

XV. Hatchetigbee section of the Lignitic .............................. 306

XVI. Wood's Bluff or Bashi section and Bell's Landing section of the Lignitic ............................................................ 310

XVII. Nanafalia and Coal Bluff sections of the Liguitic.................. 314

XVIII. Oak Hill, Pine Barren series of the Lignitic....................... 318

XIX. Ripley group of the Cretaceous formation ........................ 322

XX. Phosphatic greensands at the base of the Rotten Limestone........ 326

XXI. General section of Tertiary and Cretaceous strata of Alabama, as

exposed along the Alabama, Tombigbee, and Tuscaloosa Rivers... 334

FIG. 1. Displacement at Canton Lauding P ................................ 284

V
VI ILLUSTRATIONS.

BULLETIN No. 46.

Page. 

PLATE I. Map showing location of phosphatic deposits of South Carolina ..... 534

II. Map showing location of phosphatic deposits of North Carolina ..... 544

III. Map of European Russia, oho wing the phosphate beds .............. 586

FIG. 1. Section at Olympia, Bath County, Ky.............................. 489

2. Apatite in the Bonanza pit, Union mine, Portland, Ottawa County,

Quebec, Canada.................................... ............ 498

3. Section on south side of hill on north side of Rheaumo Lake, Templeton, Ottawa County, Quebec, Canada .................. ......... 499

4. Dike at the Union mine, Portland West, Ottawa County, Quebec,

Canada......................................................... 500

, 5. Ideal section southeast and northwest through the Emerald mine hill,

Buckingham, Ottawa County, Quebec, Canada................... 600

6. Section in a pit near the Emerald mine (looking west), Buckingham,

Ottawa County, Quebec, Canada................................. 501

7. Section of apatite vein near Smith's mine, Oso, Frontenac County,

Ontario, Canada ................................................ 502

8. Surface rock at Turner's Island, Clear Lake, Canada................ 502

9. Pyroxene surface, Star Hill, Union mine, Portland East, Ottawa

County, Quebec, Canada......................................... 503

10. Opening in the west side of a hill near Smith's mine, Oso, Frontenac

County, Ontario, Canada ........................................ 503

11. Bowlder of country rock embedded in pyroxene, etc., High Rock mine,

Portland West, Ottawa County, Quebec, Canada ................. 504

12. Section of one of the northwest and southeast veins at Foxtou's mine,

Loughboro', Frontenac County, Ontario, Canada ................. 504

13. Horizontal section showing natural cavity in vein, Loughboro', Frontenac County, Ontario, Canada .................................. 505

14. Northeast side of a pit at North Star mine, Portland East, Ottawa

County, Quebec, Canada ......................................... 506

15. Southwest side of a pit at North Star mine, Portland East, Ottawa

County, Quebec, Canada ........................................ 507

16. Southeast side of a pit at North Star mine, Portland East, Ottawa

County, Quebec, Canada ........................................ 508

17. Northwest side of a pit at North Star mine, Portland East, Ottawa

County, Quebec, Canada......................................... 509

18. Part of the northeast wall of McLaurin's mine, Templeton, Ottawa

County, Quebec, Canada ........................................ 509

J9. Section at McKenzie's opening, looking ENE., Bowman, Ottawa

County, Quebec, Canada......................................... 510

20. Section in a pit near the Emerald mine, Buckingham, Ottawa County,

Quebec, Canada................................................. 512

21. North side of the cut in the west side of North Star hill, Portland

East, Ottawa County, Quebec, Canada........................... 513

22. Section at Cubach, Nassau, Prussia, after D. C. Davies............. 521

23. Section at Staffel, Nassau, Prussia, after D. C. Davies............... 521

24. Section from Truxillo to Logrosan, Spain, after Daubeuy and Widdrington........................................................ 528

25. Ground plan of the Ca"ceres mines in 1875, after C. U. Shepard, jr... 530

26. The Estrella deposit in Estremadura, Spain, after C. U. Shepard, jr. 531

27. Section ENE. and WSW. through Pinckney's phosphate field, South

Carolina ........................................................ 538

28. Average section in Pinckney's phosphate mine, Berkeley County, S. C. 538

29. Section in one of Fishburne's pits, South Carolina.................. 939
ILLUSTRATIONS. VII

Page. 

FIG. 30. Strata overlying the phosphate bed at Castle Hayne, New Hanover

County, N. C.................................................... 547

31. Section in quarry at Rocky Hill, ou Lochloosa Creek, near Magnesia

Springs, Alachua County, Fla.................................... 553

32. Section of strata at Cwmgwynen phosphate mine, southwest of Llangynog, North Wales, after D. C. Davies .......................... 554

33. Section of strata at Berwyn phosphorite mine, west of Llangynog,

North Wales, after D. C. Davies ................................. 555

34. Distorted bed in Cambridgeshire, England, after 0. Fisher ......... 564

35. Section at Upware, Cambridgeshire, England, after W. Keeping.... 564

36. Section at Sandy, Bedfordshire, England, after J, F, Walker........ 565

DEPARTMENT OF THE INTERIOR

BULLETIN

OF T11E

UNITED STATES

GEOLOGICAL SURVEY

No. 4=2

WASHINGTON

PRINTING^ 

1387

UNITED STATES GEOLOGICAL SURVEY'

J. W. POWELL, DIRECTOR

EEPOET OF WOEK DONE

MAINLY DUJHXG TUK

FISCAJO YB^R 1885-'86

F. W. CLARKE, Chief Chemist

WASHINGTON

GOVERNMENT PRINTING- OFFICE 

1887

CONTENTS.

Page. 

Preface..................................................................... 9

SCIENTIFIC PAPERS.

Researches on the lithia micas. By F. W. Clarke ........................... 11

I. The lepidolites of Maine.............................................. 11

II. The iron lithia micas of Cape Ann ........................ ...... ...... 21

The minerals of Litchfield, Maine. By F. W, Clarko......................... 28

Elteolite............ .................................................... 28

Cancrinite .............................................................. 29

Sodalite .................. .....................................'........ 30

Hydronephelite ........................................................'. 31

Albite and lepidomelane................ ................................ 34

Discussion of formula} .................................................. 35

Turquoise from New Mexico. By F. W. Clarke and J. S. Diller .............. 39

The gneiss dimyto contacts of Cornndnin Hill, North Carolina, in relation to 

the origin of corundum. By Thomas M. Chatard ...................... 45

The localities ........................................................... 46

 Description of the sections .............................................. 48

Analytical results....................................................... 49

Conclusion.......... .................................. ............ ...... 61

A method for the separation and estimation of boric acid, with an account of 

a convenient form of apparatus for quantitative distillations. By F. A. 

Gooch ................................................................ 64

A method for the separation of sodium and potassium from lithium by the action of amyl alcohol ptf the chlorides, with some reference to a similar 

separation of the same from magnesium and calcium. By F. A. Gooch. 73 

The indirect estimation of chlorine, bromine, and iodine by the electrolysis of 

their silver salts, with experiments on the convertibility of the silver 

salts by the action of alkaline haloids. By J. Ed ward Whitfield........ 89

On two new meteoric irons and an iron of doubtful nature. By R. B. Riggs .. 94 

The Grand Rapids meteorite............................................. 94

The Abertiron.......................................................... 95

An iron of doubtful nature ...................................... 1....... 96

The effect of sudden cooling exhibited by glass and by steel. By C. Barus and

V. Strouhal................... ........................................ 98

§ I. The strain imparted by sudden cooling, and its relations to temperature 98 

§ II. The strain imparted by sudden cooling, and its structural relations.... 112

§ III. The hydro-electric effect of temper.................................. 121

Retrospective remarks..............................:.....'.............. 129

The specific gravity of lampblack. By William Hallock...... ............... 132

MISCELLANEOUS ANALYSES. *

The peridotite of Elliott County, Kentucky ................................. 136

Trenton limestone from Lexiugton, Virginia.... ............................. 137

- (5)
6 . CONTENTS.

Pago. 

Residual deposit from the subaerial decay of cliloritic schist from eight miles

west of Gary, North Carolina................ .............. ...... ...... 137

Decomposed trap from North Carolina ....................................... 138

Altered feldspar from Laurel Creek, Georgia................................. 138

Ferruginous rock from Peuolcee iron range, Wisconsin........................ 138

Two rocks from Kakabikka Falls, Kamiuistiquia Eiver, Ontario.............. 139

Mica anclesito from a canon on the east side of San Mateo Mountain, New

Mexico ....................^..................... .................... 139

Hypersthene andesite from San Francisco Mountains, Arizona..... ........... 139

Basalt from six miles northeast of Grant, New Mexico ........................ 140

Fulgurite from Whiteside County, Illinois ................................... 140

Blue and buff limestones from Bedford, Indiana.. ...... ...................... 140

Yellow sandstone from Armejo quarry, Colorado.............................. 141

Eight samples of volcanic dust.............................................. 141

Loess and clays ...................... .^...............^..................... 142

Iron ores from Louisiana ........................................:............ 144

" Natural coke " from Midlothian, Virginia .................................. 146

Coal from Jefferson County, West Virginia....... .... ......................... 146

Three coals from Gulf, North Carolina ....................................... 146

Coal from Walnut Cove, North Carolina...................... .......... ..... 146

" Natural coke " from Purgatory Gallon, New Mexico......................... 147

T\vo springs, one mile from Farmwell Station,Loudoun County, Virginia..... . 147

Two artesian wells, Story City, Iowa ..................,.............'........ 148

Becks Hot Springs, near Salt Lake City, Utah..... ........................... 148

Water of Mono Lake, California.... ......................................... 149

Index .......----................-....--.......----..---.,--------..---.--- 151

(6)
ILLUSTRATIONS.

Page.

PLATE I. Map of a portion of Western Maine................................. 11

FIG. 1. Border of lepidolite on muscovite................................... 16

2. Portion of thin section of hyclroneplielite........................... 32

3. Apparatus for determination of boric acid........................... 68

4. Grand Rapids meteorite ............................................ 95

5. Etched surface of Grand Eapids meteorite.......................... 95

6. Etched section of Abert meteorite ................................... 96

7. Diagram showing variation of the density of steel, with temperature

of annealing...................................................... 101

, 8. Polarization figures of Prince Rupert drops ......................... Ill

9. Polarization figures of successive cores of Prince Rupert drops....... 115

10. Diagram illustrating the relation of graphitic carbon and thermoelectric hardness to the hydro-electric position of steel ............. 129

(7)

PREFACE.

The present bulletin, like the preceding bulletins numbered 9 and 27, is 

intended to give a fair representation of the work done in the chemical 

and physical laboratories of the United States Geological Survey during one fiscal year. It covers, however, only such work as has been 

actually finished during the stated time, and therefore much material 

relative to investigations still in progress has been necessarily omitted. 

One paper, like two others in Bulletin 27, represents the continued cooperation of Prof. V. Strouhal, of Prague, and another bears the names 

of F. W. Clarke and J. S. Diller as joint authors. Although Mr. Diller 

is connected with another branch of the Survey, he has rendered many 

services to this division and has added much to the value of two of the 

papers herein presented. .

The two papers by Dr. Gooch cover investigations which were necessary in the course of a large series of analyses of geyser waters from the 

Yellowstone Park. The latter are held back for the present, but will 

appear in a future publication. Mr. Whitfield's research also arose out 

of similar exigencies. In each case the existing methods of determination were unsatisfactory and not exact enough for our purposes.

F. W. CLARKE,

Chief Chemist. 

(9) 9'

tt. 8. GEOLOGICAL SURVEY BULLETIN NO. 42 PL. 1

MAP OF A PORTION OF -WESTERN MAINE.
WORK DONE IN- THE DIYISION OF CHEMISTRY AND 

PHYSICS IN 1885-86.

SCIENTIFIC PAPERS.

RESEARCHES ON THE LITHIA MICAS.

BY F. W. CLARKE.

I. THE LEPIDOLITES OF MAINE.

In the western part of Maine, along a line running southeasterly from 

the Eangeley Lakes to a point on the seaboard between Portland and 

Brunswick, is a series of veins of albitic granite which are noted for 

the lithia micas and colored tourmalines that they contain. These localities, in the towns of Hebron, Auburn, Norway, Paris, and Eumford, 

are all within a narrow belt of about 40 miles in length, and with them, 

as a probable part of the same system, may be classed .the spodumene 

locality in the town of Peru. The northernmost locality is that on 

Black Mountain, in Eumford.; but a few fragments of inferior green 

tourmaline have been found about five or six miles farther north, in 

Eoxbury, a fact which indicates a prolongation of the belt in that 

direction. Similarly, a' southern extension of the belt is suggested in 

the region covered by the towns of Pownal, Durham, Yarmouth, and 

Freeport, a region from which a few specimens of lepidolite have been 

reported. The total width of the belt, so far as has been observed, appears to be not much over 15 miles.

In general character tho several localities are much alike, although 

in points of minor detail they differ considerably. With the tourmaline 

and lepidolite, quartz, muscovite, cleavelandite, cassiterite, and amblygonite are always associated; and other minerals, to be specially noted 

in the separate consideration of the localities, are often found. Some 

of the differences are doubtless due to the fact that certain localities 

have been more thoroughly opened up than others, and these would 

probably be eliminated by more complete exploration. Other differences, however, are notable and characteristic. The accompanying 

map (Plate I), which shows the geographical distribution of the localities, will be of use for reference during the following discussion.

(11) n
12 WASHINGTON LABORATORY. (BULL. 42.

For convenience we may cotfsider the lepidolites of the several localities separately, beginning with the northernmost and proceeding southward in regular order.

Rumford. The Eumford locality was discovered several years ago 

by Mr. E. M. Bailey, of Andbver, Maine, but it was "not opened up until 

1883. It is most easily approached from Andover and is situated on 

the northern slope of Black Mountain; at an estimated elevation of 

about a thousand feet above the base. As yet the excavations are 

merely superficial, although they are sufficient to show the general 

character of the deposit. A part of the lepidolite, which is very 

abundant, js fairly pure, lilac purple in color, and finely granular; but 

the larger -portion of the mineral is coarser in structure, reddish, and 

thickly sprinkled with small, opaque, red tourmalines. The color of 

the latter is very rich, and some are found in radiated masses of considerable size; but so far no true gem material has been obtained at 

the locality. The appearance of the associated lepidolite and tourmaline is strikingly characteristic and resembles nothing from the other 

localities of the region. Green tourmaline is found quite sparingly, 

and so also are amblygonite and tinstone. The spodumene, however, 

is one of the notable features of the deposit, occurring in masses of 

very great size. Faces of this mineral over a meter in length can be 

observed at several points along the vein. At the other lepidolite localities spodumene is comparatively scarce. An analysis of the granular purple lepidolite gave Mr. E. B. Eiggs the following results:

Si02 .........

A12 03 . .......

FeiOs ........ 

FeO.. ...... ..

ME.O .........

PaO

MgO.........

Li20 .........

Na*O... ......

K2O. .........

H20... .......

F.. ..........

Less oxygen.

I

51.52

25. 89

.SI

Undet.

,.20 

.16

.02

4.87

1.18

11.00

.88

5 8lf

101. 83 

2.44

99. 39

II

51.32

I 26.35

4.93

.94

11.02

1.02

5.91

In the ordinary analysis no caesium nor rubidium could be found; but 

a bare trace of the the latter was shown spectroscopically in an examination of the alkalies concentrated from 150 grammes of the mineral. 

In all the analyses the water was determined directly by means of the

(12)
CLAKKE.] RESEARCHES ON THE LITHIA MICAS. 13

Gooch tubulated crucible. Lithia was estimated by the new method 

devised by Dr. Gooch and described in another part of this bulletin. 

The fluorine was determined by the old Berzelius process. 

 Paris. The famous locality known as Mount Mica, which lies about 

a mile eastward from the village of Paris, was discovered in 1820 by 

Messrs. E. L. Hamlin and Ezekiel Holmes. Since that time large excavations have been made in search of mica and of gem tourmalines, and 

the locality is one of those most noted among mineral collectors. It has 

been thoroughly described by various writers, especially by Dr. A. C. 

Hamlin in his little book The Tourmaline.1 Quite naturally, on ac-. 

count of the long continued explorations, the list of species found at 

Mount Mica is much fuller than that for any of the other deposits; and, 

according to Mr. S. E. Carter, who has supervised much of the excavation 

and made large personal collections, it embraces the following minerals: 

Tourmaline, black, green, red, blue, white, and yellow; Beryl, green, 

white, and yellow; Quartz, rose, yellow, smoky, and crystallized; Garnet; Zircon; Albite, cleavelandite; Orthoclase ; Spodumene; Muscovite; 

Biotite; Lepidolite ; Autunite; Apatite, green, blue, and crystallized; 

Cookeite; Brookite ; CMldrenite; Yttrocerite; Amblygonite; Kaolinite; 

Halloysite; Cassiterite; Lolingite; Triphylite; Pyrite; and Tantalite (?). 

Thelepidolite occurs both in the purple, granular form, and also broadly 

foliated like muscovite. The latter variety was analyzed by Mr. Kiggs, 

and the results may well be compared with those obtained by Berwerth2 

and by Eammelsberg: 3

SiOa ...... .... ....

A1203 . ............. 

Fe2O3 .............

FeO...... .........

MnO...... ........

'LiiO... ............

Na3 0... ...........

K2O.. .............

CssO.. .............

Rb2O....... .......

HSO.. .............

F... ...............

Less oxygen . . .

Ki

I.

50.92

24.99 

.30

.23

Trace

4.11

2.23

11.50

'"Pfo pA

1.92

6.29

102. 49 

2.64

99.85

Sgs.

II.

50.68

4.29

2.00

11 25

2.00

6.31

50.39

28.19

5.08

12.34

2.36

5.15

103.51 

2.17

101. 34

52.61

28.43

4 OQ

^Q

10. 89 '

.22

*! 1Q

102.22 

2.19

100. 03

1 PublisliecTby James R. Osgood & Company, Boston, 1873,12°, 107 pp.

»Zeit. Kryst. Min,, 2, p. 523.

9 j3ee Third Supplement to Dana's System of Mineralogy p. 79,

(13)
14 WASHINGTON LABORATOEY. [BU.LL. 43.

Hebron. About 7 miles southeast of Mount Mica is the well known 

locality in Hebron, which, however, because of legal complications in 

the title to the land, has been but little worked. All the exploration, 

so far, has been superficial; and yet many fine specimens of green and 

red tourmaline, cassiterite, ainblygonite, cookeite, beryl, apatite, and 

childrenite have been obtained. The lepidolite of this locality is of 

the ordinary purple, coarsely granular kind, but is especially interesting on account of the fact that'it has supplied chemists with considerable quantities of the rare metals caesium and rubidium. The existence of these elements in lepidolite was first-pointed out by Johnson 

and Alien,1 who were working on the,Hebron mineral; and yet no complete analysis of the latter seems so far to have been published.

The following results were obtained by Mr. Biggs:

Si02 .... ..........

A12 03 . .............

Fej03 .............

FeO. ..............

MnO.... ..........

CaO. ..............

MgO........ ......

Li 2O. ..............

Na2 0.... ..........

K2 0. ..............

EbaO.. ............

Cs2 0.... ..........

H,0.. .............

F. ........... .....

Less oxygen ....

I.

48.80

28. 29

.29

09

.08

.10

.07

4.40

72

)

io or.

1.66

4. 96

101.81 

2.02

99.79

II.

48.68

> 28. 71

4.58

.76

12.06

I

on

r-> 1Q

In this case the potassium, rubidium, and caesium were weighed together as chlorides and the chlorine was subsequently determined. 

The percentages given, 12.35 and 12.06, respectively, therefore represent the actual oxides present, and not merely a computation of all as 

potash from the platinchloride. In the one case we have 10.34 of metal 

to 2.01 of oxygen, while in the second analysis we have the ratio 10.98

lAm. Jour. Sci. (II), XXXV, p. 94. 

(U)
CLAKKE.] RESEARCHES ON THE LITHIA MICAS. 15

to 1.98. If caesium and potassium only were present these would give 

by indirect calculation the following proportions of the two metals :

K2O. ..........

Cs2O...... ....

I.

11.47

.88

12. 35

II.

11.40

.66

12.06

The csesia and rubidia present, therefore, must be less than the figures given for Cs2O.

Associated with the Hebron lepidolite there have been found specimens of red and green tourmaline, which, preserving their crystalline

form, have undergone alteration into a softer mineral of an opaque, 

talcose appearance. Some of this material so derived from tourmaline 

has been supposed to be lepidolite ; and, as it was possible that a study 

of it might be of interest, an analysis of a pink specimen, originally rubellite, was made by Mr. Eiggs. The specific, gravity, as determined by 

Mr. T. M. Chatard, was 2.87. Analysis is as follows :

SiOs ..

A1203 . 

Fes03 . 

FeO.. 

MnO.. 

CaO.. 

MgO.. 

Na2O. 

K2 0.. 

H20.. 

F......

..... ................................. 43.90

.....'................... .............. 38.71

..... .............................. .... .58

................... ................... -.25

....................................... .04

........,...........................*. .41

....................................... .05

....................................... 1.05

....................................... 10.92

............. ......................... 4.25

....................................... None

B203 ............................................. Strong trace

100.16 .

These results show clearly that the alteration product is nob lepidolite, but damourite, a fact which could hardly be altogether unexpected.

Auburn. In the western part of this town, near the Minot line, there 

are two localities, less than half a mile apart, yielding lepidolite with the 

associated minerals. The one longest known is small and apparently unimportant, while the other, lying about southeast of the first, upon the 

farm of Mr. G: 0. Hatch, has been thoroughly opened. It has yielded 

a large number of gem tourmalines, mostly of the paler greenish, lilac, 

or lavender colors, unusually fine crystallizations of apatite, and perhaps the best crystallizations of lepidolite so far known.1 Cookeite, 

orthoclase, albite, cassiterite, muscbvite, biotite, beryl, garnet, quartz,

 For a description of this locality, see G. F. Kunz, Am. Jour. Sci. (Ill), XXVII, p. 303.

(15)
16 WASHINGTON LABORATORY. I DULL. 42.

and amblygonite are among the other species here found. The lepidolite occurs in the ordinary purple, coarsely granular form, and also in 

remarkable perfection as a border upon inuscovite, the broad plates of 

the latter being practically encircled by aggregations of small crystals of the lithia mica. Some specimens of this type have also been 

found at Paris, but the Auburn examples are much finer than those 

from other localities. The accompanying illustration (Fig. 1) shows the 

peculiar association of the two minerals.

FIG. 1. Border of lepidolito on muscovite.

As it was hoped that this mode of occurrence of lepidolite might 

throw some light upon its genesis, three analyses of material from Auburn were made by Mr. Riggs: first, of the common granular variety; 

secondly, of the border upon muscovite; and, thirdly, of the muscovite 

itself from the center of the second specimen. The results were as follows, the lithia being determined by the old phosphate method ;
RESEARCHES ON THE LITHIA MICAS. 17

Si02 ....................

A1303 .. .................

Fe2 03 ...................

FeO

MnO.... ................

CaO ........ ..!..... . ...

MgO..... ...............

L'aO.. ...................

NasO... ....... ...........

K3 0.. ..................

BbsO.. ............. ....

CSjO. ...... .............

H3O.... ................

F ......................

I. Granular lepidolite.

51. 11

25.26

.20

.07

.17

.12

.01

4. 76 5. 17

1. 52 1. 35

10.511 f

1. 29 \ 12. 21^

 45J I

. 88 1. 01

6. 57 6. 67 6. 60

102. 94 

2.76

100. 18

II. Border on 

muscovite.

49.62

27. 20

.31

.07

o55

4.50 4.17

o in o OK

8.03

2.44

.72

1.52

5.45 5.78

102. 51 

9* QQ

100. 22

HI. Muscovite.

44.48

35.70

1 fll

1.07

T^rsj PA

.10

Trico

2.41

Q 77

5

CA

.72

100. 84

Of)

100. 54

In these analyses the determinations of csesia and rubidia are to be 

considered merely as rough approximations. The caesium was separated 

as stanniehloride, and the rubidium and potassium were computed from 

the amount of chlorine in the mixed chlorides of the two metals. In 

the oxides K2 0, Kb2O, and Cs2O, taken together, the actual ratio of 

metal to oxygen in analyses I and II is as follows:

Oxygen ...............

(KRbCs)20 ............

I

10.32

1.93

12. 25

10. 26

1.95

12 21

II.

9 57

1.62

11 1Q

Norway. Thislocality, which has been but little opened, is about seven 

miles from Mount Mica, in a southerly direction. With the lepidolite are ' 

associated, as usual, quartz, the feldspars, the micas, cassiterite, lithiophilite, beryl, &c., and also a peculiar rose red clay, derived from some 

other species by alteration. Most of the colored tourmaline is of a peculiar dark oily green tint, and the lepidolite is partly of a coarsely 

granular white variety and partly of a brownish, very finely granular 

sort, . ,

(17)

Bull. 42-
18 WASHINGTON LABORATORY. : [BULL. 42.

Analyses of both varieties by Mr. Biggs came out as follows:

SiO,.... ...... ..................

A12 03 . ...........................

Fe203 ...... .....................

FeO... ..........................

MnO.. ........ .....I.... ........

CaO...... ...... ................

MgO.. .......... ................

Li2 0 ............ ................

Na2 0...... ......................

K2O .......... ..................

KbaO.... ........................

Cs20 .................... ........

H30.... .........................

F ...............................

White.

40 e:o 40 4=:

28.80

.40

,24

.07

.13

.02

3.87

.13

8.82\

3.73 1 12. 70

.08J

1.60 1.85

5. 18 5. 39

102. 59 

2.18

100. 41

Brown.

50.17

25.40

.87

AK.

OQ

Undet.

Undet.

4 no

13.40

2 no

5.05

101. C2

2

10

99.49

The analysis of the brown variety was only partial.

The lithia was determined by the phosphate method, while, as in the 

case of the Auburn material, the caesia and rubidia estimations are merely 

approximative. The actual ratios between metal and oxygen in the potassium group, as found in the two experiments upon the white lepidolitc, are subjoined:

Mptnl

(KRbCs)20.. ................................

10.83

1.80

12.63

10.91

1 7Q

19 70

The fact that this lepidolite is the richest of the series in these rare 

metals becomes doubly interesting when we remember that a beryl from 

the same or a nearly adjacent locality gave Penfield 1.66 per cent, of 

ceesia.1

' Of the rose-red clay, previously mentioned, a partial analysis was 

published in Bulletin No. 9, U. S. Geol. Surv. The following complete 

analysis by Mr. Biggs is better, and shows, in spite of some little nonuniformity of composition in the material, that it is to be classed most 

definitely as cimolite:

SiOs ...................... ..... ......... .- . 66.86

A1203 -----...-------............... .. .- i- 22.23

Fe2O3 ................................................... .47_

i Am. Jour. Sci. (Ill), XXY, p. 28. The Hebrou beryl contains 2.92 per cent.

(18)
RESEARCHES ON THE L1THIA MICAS. 19

FeO . 

MnO. 

CaO . 

MgO. 

Li2O .

K2O 

H20 

F ..

Less oxygen

.18 

.07 

.42 

.33 

.29 

.46 

.18 

8.26 

.06

99.81

.02

99. 79

Formula, Al2H4 (SiO3 )5. 

It is not easy to determine, from the specimens at hand, from what 

species this clay has been derived.

DISCUSSION OF RESULTS.

The foregoing analyses of the Maine lepidolites cover several distinct 

types of the mineral from five different localities, and yet they indicate 

a very great constancy or uniformity of composition. For convenience 

of comparison, we may tabulate the results, using mean values whenever 

two determinations of a constituent have been made. Two exceptions 

to this rule, however, have been adopted, namely, to use the higher 

determinations for silica and the lower for fluorine, because of the known 

direction of the experimental errors in the analytical processes. Slight 

loss of silica, when fluorine is present, is difficult to avoid; and so also 

slight impurities in the calcium fluoride can hardly be eliminated. 

.With these qualifications the analyses may be stated as follows:

no2 ...... ......................

A12 03 ...... ....................

FesOj......... .................

FeO...... ......................

MnO...........................

p->n

MgO...........................

LiaO.... ........................

TSaaD. ...........................

KtO...... ......................

RbsO. ..........................

CszO ...........................

H20. ......... ..................

F.... ...........................

Kumford, 

purple.

51. 52 

25.96 

.31 

Undet. 

.20 

.16 

.02 

4. 90 

1.06 

11.01

.95 

5.80

101.89 

2.44

99.45

Paris, foliated.

50.92 

24.99 

.30 

.23 

Trace 

Trace 

Trace 

4.20 

2.11 

11. 38 

Trace 

Trace 

1.96 

6.29

102. 38 

2.64

99.74

Hebron, 

granular.

48.80 

 . 28.30 

.29 

.09 

.08 

.10 

.07 

4.49 

.74

! 12. 21 

j 

1.73 

4. 9C

101. 86 

2.02

99.84

Auburn.

Border.

49. 62 

27.30 

.31 

.07 

.55

4.34 

2.17 

8.03 

2.44 

.72 

1.52 

5.45

102. 52 

2.29

100. 23

Granular.

51.11. 

25.26 

.20 

.07 

.17 

.12 

-.01 

4.98 

1.43 

10.51 

1.29 

.45 

.94 

6.57

103. 11 

2.76

100. 35

Norway.

White.

49.52 

28.80 

.40 

.24 

.07 

.13 

.02 

3.67 

.13 

8.82 

3.73 

.08 

1.72 

5.18

102. 71 

2.18

100. 58

Brown.

50.17 

25.40 

.87 

.45 

.23 

Unde.t. 

Undet. 

4.03 

1 

} 13.40

j

2.02 

5.05

101. 62 

2.13

99.49

(19)
20 WASHINGTON LABORATORY. [BULL. 42.

With this table may be advantageously compared the following 

analyses of lepidolite from three foreign localities i 1

Si02 ... ............................................

AhOs.- ...........................................

FezOs..-.. ...... ..................................

FeO....... ........................................

MnzOs .................................... .......

CaO................ ...............................

MgO... ...........................................

LiaO. .............................................

NaaO.... ................................. ... .

KsO.. ............... .............................

H2 0 .............................................

F ......................................

Cl. ...... ............................... ... .

PcOs .............................................

Rozena.

Ber- 

 werth. ,

50.98 

27.80

.05

5.88

10.78 

.96 

7.88

.05

104. 38 

3.37

101.01

Ramraelsberg.

51.32 

26.00

1.30

3.87 

.96 

9.98 

.57 

7.18

101. 18 

3.02

98.16

Cornwall, 

Bammelsberg.

51.70 

26.76

1.29 

.40

1.27 

1.15 

10.29

? 7.12

.16

100. 38 

2.99

97.39

Juschakova.

Kosales.

48.92 

19.03

5.59 

.14

2.77 

2.23 

10.96

10.44 

1.31

101. 39 

4.68

96.71

Kammelsberg.

. 50. 26 

21. 47

5.36

4.88 

.54 

11.08 

.66 

8.71 

1.16

104.12 

3.93

100. 19

Few other lepidolite analyses are worth quoting, except possibly 

Cooper's analysis of the Eozena mineral, in which he found 0.24 per 

cent, of rubidia and a trace of ccesia.2 The essential identity of the 

material from Maine, Rozeua, and Cornwall is thus made clear, while 

the lepidolite from Juschakova is different in its large percentage of 

manganese, its higher fluorine, and its trace of chlorine. In the last 

named mineral of course the manganese replaces an equivalent amount 

of alumina, and the function of chlorine is the same as that of fluorine. 

In the other analyses, to speak in general terms, the water and fluorine 

vary sonifiwhat reciprocally, suggesting the ordinary replacement of the 

latter element by hydroxyl. With this assumption, if it may be called 

so, the formula of lepidolite may be written thus:

Al2 (SiO3) 3F2LiK;

a formula which has.long had general acceptance, but which is now put 

upon a surer basis by the wider range'of analyses. It corresponds to 

the following theoretical composition :

'

Si02 .....

A1 2 O3 ....

'Li3O ....

K2 0..... 

F. ......

Calculated.

49.18

27.87

4.09

12.81 

9.84

Si08 .. .......

A1303 .. ......

Li.2O ........

(NaKRbC»)aO. 

(F,HS0) ......

Found (Riggs).

48. 80 to 51. 52

24. 99 to 28. 80

3.87 to 4.98

12. 07 to 13. 68 

6. 69 to 8. 25

1 See Dana's System of Mineralogy, p. 315, and Third Supplement, pp. 78, 79.

2 Pogg. Ann., pp. 113, 343.

(20) '
CLAUKK.J RESEARCHES ON THE LITHIA MICAS. 21

Most of the variations from theory are 110 greater than we should expect to find them with material so difficult to secure in absolute purity 

as lepidolite. The granular structure of the species is peculiarly* favorable to the presence of inclusions of foreign matter, such as albite, for 

example, to which latter impurity some of the soda found in the analyses is very probably due. The greatest difference is in the case of 

fluorine, although the foreign analyses notably Kammelsberg's analysis of the Juschakova mineral contain very nearly the full theoretical 

amount. If, however, the fluorine is present in the univalent group 

A1F2 , it is possibly replaceable in part by the similar group A1O, a supposition which easily accounts for all the variations. With this supposition it becomes a simple matter to write a probable structural formula 

for lepidolite, as follows:

 Si03 -Al=F2 .

SiOs-K. 

SiOs-Li.

Thus the mineral is regarded as a definite substitution derivative of 

the normal aluminum inetasilicate Al2 (SiO3) 3 , one atom of Al having been replaced by the three univalent factors represented above. 

Another view of its structure is given at the close of this paper.

II. THE IRON LITHIA MICAS OF CAPE ANN.

In the granite quarries of Rockport, Massachusetts, near the extremity 

of Cape Ann, there are occasional veins of feldspathic character which 

contain, along with the ordinary constituents of such veins, the rare 

minerals danalite, fergusonite, cyrtolite, amazon stone, and certain 

remarkable micas. One of the latter, cryophyllite, was described by 

Cooke in 1867.1 who also analyzed an associated " lepidomolane," to 

which Dana afterwards gave the name of annite. The vein from which 

Cooke obtained his niaterial was long ago blasted away or covered up, 

but other veins of like nature are still accessible, and from one of them 

the micas examined in this laboratory w.ere obtained. They were collected for the United States National Museum by the original discoverer 

of the locality, Mr. W. J. Knowlton, and were, to all outward appearance, identical with the micas described by Cooke. The analyses, however, reveal notable differences between the older and the newer material and add great interest to the micas of the locality.

In the collection furnished by Mr. Knowlton two micas were clearly 

recognizable, the one a dark greenish black lithia mica, presumably 

cryophyllite, and the other a black, brilliant lepidomelane. In some 

specimens the cryophyllite formed a border of small crystals around the 

broader plates of annite, precisely as in the association of lepidolite and

'Am. Jour. Sci. (II), XLIII, p. 217. 

(21)
22 WASHINGTON LABORATORY. [BULL. 42.

muscovite at Auburn. The resemblance in this point is curiously striking, only that the Rockport specimens are less conspicuous than those 

from Auburn, since they lack the contrast of color by which the latter 

are characterized.

The lithia mica, or cryophyllite, varies considerably in external charac 

ter, and three well marked types of it were selected for analysis: first, 

\.he broadly foliated, brilliant, blackish green mica, which showed no 

trace of alteration; secondly, a paler, dull green, less lustrous variety, 

apparently somewhat altered upon the surface; thirdly, an aggregation of minute six-sided prisms, so small as to give the mineral an almost 

granular appearance, similar to an ordinary dark green chlorite. The 

analyses were made by Mr. Eiggs, who used the Gooch process for 

separating lithia and Berzelius's method for the fluorine. The results 

were as follows:

SiO2 ...........

A1203 ..........

FeaOa. .........

FeO ...........

MnO.... .......

CaO ...........

MgO.... .......

Li 2 0 ...........

Na2 0 ..........

K2 0 ...........

HaO ...........

F...... ........

Less oxygen .

Foliated.

51.96 51.74

16.89

2.63

6. 35 6. 29

.24

.12

.03

4. 93 4. 80

.92 .81

10. 66 10. 73

1.22 1.40

. 6. 78 6. 86

102. 73

2.86

99.87 '

Altered.

51.46 51.35

16.22

2.21

7. 66 7. 60

.06

Trace

.17

4.83 4.78

.95 '.82

10. 65 10. 65

1.06 1.18

7. 44 7. 60

102. 71 

3.11

99.60

Granular.

52.17 52.07

16.39

4.11

6. 08 5. 90

.32

Trace

Trace

5.03 4.95

.60 .66

10. 54 10. 42

1. 43 1. 48

7. 02 7. 20

103. 69 

2.95

100. 74

(22)
RESEARCHES ON THE LITHIA MICAS. 23

These results demonstrate the essential identity of the three specimens, but do not sharply correspond with the figures given by Cooke. 

In mean, using, as in the case of the lepidolites, the maximum silica and 

minimum fluorine determinations, they may be compared with Cooke's 

analysis as follows:

Si02 ...... .........

A1203 ...... ........

Fe2O3 ........'.....

FeO. ..............

MnO ..............

CaO ..............

M°-0 . - - .

Li 2O ...... ........

Na2 0...... ........

KaO...:.. .........

HaO ...............

F... ..............

Riggs.

51.86

16.50

2.98

6.65

21

.04

.07

4.89

.79

10.61

1.29

7.08

102. 97 

2 Q8

99.99

Cooke.

51.49(+1.97)

16.77

1 97

7 98

Mn2 03 . 34

.76

4.06

Trace

13. 15. Tr. Rb2 0

SiF4 3.42. F, 2. 49

99. 94

It will be seen at once that Cooke's mineral contains only about onethird of the fluorine found in the later analyses and that it runs notably higher in silica and alkalies. In general terms the same mineral 

is represented by both analyses, with the presumption as to purity in 

favor of the specimens examined by myself. If we assume that Cooke's 

material contained a slight isomorphous admixture of some other micaceous species poor in fluorine, the most important difference is accounted for.

Inasmuch as some writers have been inclined to identify cryophyllite 

with zinnwaldite, a comparison of the two species may be instructive. 

The published analyses of ziunwaldite vary widely, especially in the 

amounts of iron; but the older figures are subject to doubt as regards 

the relative proportions of ferrous and ferric oxides. Two comparatively recent analyses by Berwerth and Eammelsberg. however, agree 

fairly well with each other, although, compared with former determinations, they run low in iron. The comparison between the analyses 

is subjoined:

(23)
24 WASHINGTON LABORATORY. [HULL. 42.

Si02 ..........

A12 03 . .........

Fes03 .........

FeO.... .......

MnO ..........

PiO

MgO ..........

Li 2 0 ..........

NajO.. ........

K8 0.. .........

H20... ........

F.. ...........

P

/-v

Cryopbyllite, 

Eiggs.

51.86 

1C. 50 

2:98 

6. 65 

.21 

.04 

. .07

4.89 

.79 

10.61 

1.29 

7.08

102. 97

Zinnwaldite.

Berwerth. 1

45.87 

22. 50 

.66 

11.61 

1.75

3.28 

.42 

10.46 

.91 

7.94 

.08

105. 48

Eammelsberg.*

46.44 

21.84 

1.27 

10.19 

1.57

.18 

3.36 

.54 

10.58 

1:04 

7.62

104. 63

'Zeit. Kryst. und Min., II, p. 525. "-Sec Third Supp. to Dana's Syst. Min., p. 79.

Eeduced to empirical formulae these analyses give two quite different 

ratios, which, however, do not admit of very simple expression :

Cryophyllite :

or, Al3 (Si03)6F2R/6. 

Zinnwaldite: FesHaKJ^AlsF 

or, Al4(Si03)7F4R/8.

The further consideration of these formulae may be deferred until the 

latter portion of the paper. For present purposes they serve to show 

the non-identity of the1 two minerals.

For the lepidomelane, or annite, of Eockport, quite unexpected results were obtained. The material analyzed by Mr. Eiggs was black, 

brilliant, broadly foliated, and apparently very pure. Upon the specimens examined same purple fluorite was visible. The water estimations were directly made with the Gooch tubulated crucible.

(24)
EESEARCHES ON THE LITHIA MICAS. 25

SiO8 ... ............

Ti03 ...............

Al a03 .... ..........

Fe2 03 .............

FeO.... ...........

MnO ..............

CaO...... ..........

MgO... ...........

Li3O ..............

Na3 0...... ........

KsO. ..............

H20... ............

F.... .............

Rifigs.

31.96

3.42

11.93

8.06

30.35

21

.23

.05

1.54

8.46

4.25

Trace

100. 46

Anuite.

Cooke.

39.55

16. 73

12.' 07

17. 48

Mna03 .60

.62

.59

10. 66

1.50

SiF4 ' . 62

100. 42

It is at once evident that two entirely distinct micas are here represented, and the question is raised as to whether the Eockport granites 

may not contain a series of complex isomorphous mixtures. Cooke, indeed, pointed out the isomorphism of cryophyllite with the lepidomelane which he had analyzed, and showed that the lithia and the fluorine in the latter were probably due to admixtures of the former. We 

now see that more than two micas are involved in the problem, and the 

difficulty of establishing accurate formulae for the several species becomes enormously increased. For the present, approximate formulae 

only can be assigned, involving various assumptions and representing 

probabilities rather than complete interpretations of the facts. If we 

unite the groups TiO2 and SiO2 in our annite and regard the ferric iron 

as belonging partly with the alumina and as partly having been the 

result of oxidation from the ferrous state, we have the two following 

general formulae for the two analyses:

Annite, Cooke, R'8Al4 (Si04 )6. 

Annite, Riggs, R'i4Al2 (Si04) 5.

For the latter, the equivalent of R' is approximately K2H4Fe"4 ; and 

for the former it is K2H2 Fe"2 . These values correspond to the following percentage compositions:

SiOa . .............. ........

A1303 - ......... .............

FeO........... ............

K2 0. ......................

H,O. ......................

Cooke.

39.5

26.8

18 9

12.4

2 4

100.0

Riggs36.6

12 4

 ^ 1

11.5

4.4

100.0

(25)
26 WASHINGTON LABORATORY. [H.n.t,42. .

Attention has already been called to the fact that some specimens of 

cryophyllite are borders upon plates of annite, precisely as the lepiddlite of Auburn is arranged about nuclei of muscovite. It accordingly 

becomes quite probable that a similar relation connects the two pairs 

of minerals, and upon that relation the form uke so far assigned shed 

some light. In each case we have a mineral with metasilicate ratios 

implanted upon an orthosilicate, and a derivability of the one from the 

other is strikingly suggested. Structural analogies also appear, for in 

each pair we have a common type of nucleus, which maybe represented 

as follows :

Muscovite nucleus, A1 (8104)3. Annite nucleus, Al 2 (Si04 )5 . 

Lepitlolite nucleus, Al(Si03 )3. Cryophyllite nucleus, Al.2 (Si03 )6.

The development of complete structural formulae from these nuclei is 

rendered difficult by our ignorance of the part which fluorine plays in 

such compounds. In the formula previously assigned to lepidolite the 

fluorine is represented as combined with aluminum in the univalent 

group A1F2 ; but a similar representation becomes difficult, if not impossible, in the case of the two iron micas. A different solution of the 

problem must therefore be sought, and. it probably is to be found by an 

application of the generally recognized principle that fluorine and hydroxyl can replace each other isomorphously.

If, now, we start with orthosilicic acid Si(OH)4 and regard the hydroxyl groups as successively replaceable by atoms of fluorine, we can 

conceive of a series of acids ranging from Si(OH)4 to SiF4 ; and by the 

aid of such a supposition many of the fluoriferous silicates may be rationally explained. For example, the acid SiF(OH) 3 may be considered, 

and its nucleus SiFO3, a trivalent residue, may be applied to the discussion of the lithia micas. Upon this supposition the empirical formula for cryophyllite, Al2F2Si5Oi5R'6 , and the similar formula for lepidolite, ALjl^SiaOgK's, become curiously significant, especially wh'en they 

are written out in contrast with two other fo.rmulflB, as in the subjoined 

scheme :

Muscovite. Annite (Cooke). Annite (Kiggs). 

.8104 = R'3 Si04 ' 

AieSiO4 =5Al Al^-Si04 

8i04 = Al

Lepidolite. Cryophyllite.

SiF03 = R'2 

Al4Si03 -R'

SiF03 m

Al^SiO3 R' 

SiF03 = R'2

To the zinnwaldite, as represented by the newer analyses, no probable structure is assignable, and it is very possibly a mixture of isomor-

(20)
CLABKB.] RESEARCHES ON THE LITHIA MICAS. 27

phous species. Indeed, the old analyses indicate great variability in its 

composition, and it needs to be more thoroughly studied, not only for 

itself, but also in its relations to whatever other micas may be associated with it. The matter of association can never, in the study of the 

micas, be safely neglected.

Although the formulae herein assigned to annite and cryophyllite 

are purely provisional and approximative, at least as regards the values ascribable to B', it may be set down as practically certain that the 

ratios between the sesquioxides and the silica are correctly given. 

These ratios are the ratios of phlogopite, with which, therefore, rather 

than with the lepidomelanes and biotites, the Rockport micas are chemically to be classed. Zinnwaldite is already so classed by Tschermak 

and others, and cryophyllite falls easily into the same category. A 

typical phlogopite is fairly represented by the subjoined formula:

SiFO3 = Mg 

si04 = 

Si04 = M 

Si04 =EM 

SiF03 =

(27)
THE MINERALS OF LITGHFIELD MAINE.

BY F. W. CLARKE.

In Kennebec Couuty, Maine, along and near the boundary between 

the towns of Litchfield and West Gardiner, are scattered many bowlders of an elseolite rock. For many years these have yielded to collectors of minerals superb specimens of blue sodalite, yellow cancrinite, 

and zircon; but although the parent ledge appears at several points, 

it seems nowhere to have been opened. In addition to the minerals 

already mentioned, the bowlders contain albite, lepidomelane, a black 

mineral resembling columbite, a flesh colored mineral which has been 

called indiscriminately eloBolite or cancrinite, and a massive alteration 

product known to local collectors under the provisional name of "white 

sodalite." Although specimens from the locality are widely distributed 

in cabinets, some of the minerals seem to have been but partially described ; and I have therefore thought it worth while to study them 

somewhat closely. The supposed columbite I have not examined, for 

want of material; the zircon I have omitted, since it has been sufficiently studied by Gibbs; 1 'but the sodalite and caucriuite, although 

they had been well analyzed by Whitney,2 1 have included in my investigation, for reasons which will appear below,

BLJEOLITE.

This species occurs abundantly in Litchfield and West Gardiner in 

characteristic, dark gray, cleavable masses of strong greasy luster. 

Since it is the typical mineral of its group and as I can find no published analysis of it from this locality, the following results may have 

value as a matter of record :

HaO ................................................... .86

SiO3 ..........I. ........................................ 43.74

A12 03 .................................................. 34.48'

CaO ................................................... Trace

MgO................................................... Trace

. K2 0 ................................................... 4.55

Na2O .................................................. 16.62

100.25

1 Pogg. Ann., LXXI, 559. 2 Pogg. Ann., LXX, 431. 

28 (28) ' .
CLARKE.] MINERALS OF LITCHFIELD. 29

The specimen analyzed contained minute inc1 ions of black mica, 

but not enough of them to notably affect its composition. The analysis 

agrees fairly well with the published analyses of el^olite from other 

places.

CANCEINITE.

This mineral is one of the most abundant and characteristic at the 

locality and varies considerably in appearance. Two analyses of it 

were made by Whitney, one of the yellow variety, the other of a green, 

ish modification. I have myself seen nothing to answer to the latter 

description, but have selected three typical samples for investigation. 

They may be briefly described and indicated as follows:

A. Bright orange yellow, with strong luster and cleavage, transparent 

ill thin fragments.

B. Dirty pale yellow, less lustrous, highly cleavable, also transparent 

in thin fragments. . . C. Bright yellow, granular the commonest variety.

For ease of comparison I have tabulated the analyses side by side 

with Whitney's, indicating his yellow cancrinite by D and his greenish 

variety by E. The carbonic acid determinations were made for me by 

Mr. E. B. Eiggs, who used the Gooch tubulated crucible and collected 

the gas evolved directly in a potash bulb.

SiOz...... ....... -.---T ,....- ..---.....---....-..-. ......

AlsOs.. ........ ........ .....................................

MmOa.... ...... ........................................... -

CaO.. ...................-.........--..-..- - -- -- -- 

NasO.- ....................... ............. ..................

K,0. .......................... ..........................

MpO.. .......... ............ ...............................

H2 0....... .................................................

COa. ........... .............................................

-

A.

36.29

30.12

Trace

Trace

4.27

19. 56

.18

2.98

6. 9G

100. 36

B.

35.83

29.45

Trace

5.12

19.33

.09

3.79

6.50

100. 11

C.

37. 22

28.32

Trace

Trace

4.40

19.43

.18

.07

3.86

6.22

99.70

D.

37.42

27.70

I .86

3.91

20.98

' .67

2,82

5.95

100. 31

E.

37.20

27.59

.27

5.26

20.46

.55

3.28

5.S2

100. 53

It will at once be observed that cancrinite A, which, from its appearance, was presumably the purest type of the mineral, is the highest of my 

series in carbonic acid and the lowest in water. It is also the highest in 

soda and alumina. Whitney's two analyses show more potash than 

mine, but in other respects run fairly near C, which, as I have said, 

represents the commonest and probably the least pure variety. But, 

in order to understand the variations better, we must consider the 

flesh colored mineral referred to in my .introductory paragraph, which, 

as I have said, has been called indiscriminately elaeolite or cancrinite, 

according to the fancy of the collector. It sometimes occurs in specimens of considerable size, is lustrous and cleavable, and to the eye ap-

(29)
30 WASHINGTON LABORATORY. [BULL. 42.

pears perfectly homogeneous. An analysis gave the following results,

the carbonic acid, as in the other cases, being determined by Mr. Riggs:

SiOjj..-.-............................./..:............... 38.93

A1203 ................................................... 32.52

CaO.................................................... 2.47

Na.3 0 ................................................... 17.02

K3O .................................................... 3.23

H2 0 .................................................... 2.83

COB ......................................... .......... 2.95

99.95-

These figures plainly indicate that the mineral is a mixture of elaeolite and cancrinite, but do not show whether the mixture is mechanical 

or due to isomorphism. To determine this point, Mr. J. S. Diller kindly 

undertook a microscopic examination of the material, comparing it in 

thin sections with the el zeolite and cancrinite B, from the specimens 

of which portions were previously analyzed. He found the mineral to 

be a merely mechanical commingling of the two species, in nearly equal' 

proportions, and later he succeeded in separating them by means of 

Sonstadt's solution. This fact, considered together with the apparent 

homogeneity of the material, renders it probable that the variations in 

composition of the cancrinite are due to small admixtures of elceolite, 

and that Whitney's specimens were rather more so contaminated than 

mine. Still, the entire series of cancrinite analyses are fairly concordant and confirmatory of one another. In discussing the formula of the 

mineral, however, analysis A will be given preference.

SODALITE.

On account of its beauty and its intense blue color, this mineral, as 

it occurs at Litchfield, is a favorite among collectors. It is now s'omewhat scarce, at least in large or compact specimens, and it ought to be 

carefully searched for in place. It often occurs intermingled with cancrinite, forming beautifully mottled masses, and also is associated intimately with the white, massive alteration product to be described later. 

The following analysis was made partly for comparison with Whituey's 

and partly to aid in the study of the accompanying white mineral:

SiOs ........ ....... ......................................

Ala03 -. ................ .................................

Fe2O3 .. .......... ................................ ........

Na20.. .......................................... ........

KS0... . ..--....'. ............................... ......

Cl... .............-.... ..----....................-. ...

HSO... ..................................................

Deduct O C1. .............. ..............................

Clarke.

37. 33

31.87

24.56

.10

6.83

1.07

101. 76 

1.54

100. 22

"Whitney.

37. 30 37. 63

> 32. 88 30. 93

I ...... 1.08

23.86 25.48

. 59 Uudet.

6. 97 Undet.

101. 60

(30)
CLAUKE. | MINEKALS OF LITCHFIELD. 31

In my analysis iron was not looked for, because the ignited alumina, 

which should have contained it if present, was perfectly white. Otherwise the analyses agree tolerably well.

HYDKONEPHELITE, A NEW SPECIES.

Intimately associated with the sodalite is the white alteration product mentioned in the 'last paragraph. So close is the association in 

fact and so similar in occurrence are the two minerals that the latter 

has been called white sodalite by the local collectors. Like the sodalite it is found in seams, and yields specimens as much as two centimeters in thickness; it is white, lusterless, and has the fracture of socialite, and probably it originated from the alteration of the latter. 

Two specimens of it, received from two different collectors, were analyzed, with the following results:

HaO. ..........

SiOa .. .........

A12O3 . .........

CaO.... ......

Na 20. .........

KaO. ..........

Cl ............

A.

13.12

38.90

33.98

.05

13 21

1.01

100. 27

B.

13.30

TO 24

33.16

13.07

.88

99.65

The alumina carried a trace of iron, and a doubtful trace of manganese was also indicated; hardness, 4.5; fusible easily to a white 

enamel; soluble in hydrochloric acid and gelatinizing upon evaporation ; fracture irregular, resembling that of the sodalite. In general, 

the mineral may be said to have the appearance of a slightly altered 

feldspar, minus the distinct cleavage.

These analyses left little doubt in my mind that I had a new mineral 

to deal with, and one belonging to the zeolite family. Such minerals 

are well known derivatives of the nephelite group, and thomsonite and 

natrolite have especially been often noted. In composition the new 

product differs distinctly from natrolite, but agrees in ratios approximately with thomsonite; forming, so far as chemical evidence alone 

goes, the soda end of a series passing through rauite up to ozarkite, 

the last named mineral being the nearest towards the lime end of the 

series. A comparison of the analyses of these elseolite derivatives>is 

worth making, on account of its suggestiveness. The ozarkite was 

analyzed by Smith and Brush; the rauite, from Brevig, l)y Paykull. 1

r. deutscli. chern. Gesell., VII, p. 1334. 

(31)
32 WASHINGTON LABORATORY. [HULL. 42.

H2 0...........

Si02 ..........

A1 2 03 .........

Fc,03 . ........

CaO ..........

Na2 0. ........

K,0. ..........

Ozarkite.

13.80

36.85

29 42

1.55

13.95 

3.91

99.48

Eauite.

11 71

39. 21

31.79

.57 5.07' 

11.55

91). 90

Hydroncpholite.

13.12

38.90

33.98

.05 

13 21

1.01

100. 27

Inasmuch, however, as massive minerals, and especially those which 

are produced by processes of alteration, are always subject to doubt, I 

requested Mr. Diller to assist me with a microscopic examination of 

the new substance. He very kindly acceded to. my request, and I subjoin an abstract of his results. In his report on it he says:

"A section was carefully prepared so as to show both the sodalite and 

the white lusterless mineral associated with it in such a way as to reveal their relations. The accompanying figure illustrates a small portion of the section as seen under the microscope.

FIG. 2. Portion of thin section of hydrouephelite.

"The unaltered sodalite (1) is quite irregular in form, so that the position of the section with reference to the crystallographic axes could not 

Be determined. Although of a distinct, cobalt blue color in the small frag-

(32)
CLAUKE.I MINERALS OF LITCHFIELD. 33

ment, it appears colorless and transparent in the thin section, and under the microscope it is seen to contain numerous liquid inclusions. It 

is penetrated'by many irregular fissures, which are enlarged in the process of alteration and filled with its clouded products. The extremely 

irregular line between the socialite and its secondary products is well 

defined in transmitted light, but is eyeu more distinct between crossed 

uicols from the fact that the sodalite, being isotropic, remains dark in 

all positions, while the other minerals are more or less brilliantly colored. The secondary products, which have clearly resulted from the 

zeolitization of the sodalite, are two in number. One of them forms very 

much the larger portion, probably nearly 90 per cent, of their total 

amount, and the other is embedded in the first in the form of distinct 

grains. Under the microscope in transmitted light the predominating 

mineral, which is doubtless a zeolite as shown by your analyses, is more 

or less deeply clouded, like decomposed feldspar. Between crossed nicols it breaks up into flaky grains, w-hich vary considerably in the intensity of their color; some remain dark, others range through light and 

medium tints of red and yellow, according to the position of the section. The isotropic grains in converging light are proved to be distinctly 

uniaxial and positive, and the anisotropic ones, so far as can be determined, exhibit parallel extinction. It is evident therefore that the zeolite must be either quadratic or hexagonal in the system of its crystallization. Some of the grains show an indistinct'striation approximately 

parallel to the vertical axis, but a distinct cleavage could not be discerned. In basal sections three sets of fractures could be rarely made 

out with, sufficient distinctness to suggest that the mineral is probably 

hexagonal. The mode of its occurrence indicates clearly that it has resulted from the zeolitization of the sodalite, a phenomenon which has 

been observed in many rocks. The small?grains of the other secondary 

mineral are so intermingled with the uniaxial zeolite as to indicate that 

both are derived from the sodalite. They are easily distinguished from 

the zeolite in which they are embedded. In transmitted light they are 

perfectly clear and transparent, with so high an index of refraction as 

to appear to rise above the surrounding mass. The grains are entirely 

without crystallographic boundaries, but are traversed by distinct 

cleavage lines. Between crossed nicols they are much more brilliantly 

colored than the associated zeolite, and if the section is rotated they 

become dark when the cleavage lines make a prominent angle (15°-33°) 

with the principal sections of the prisms. The mineral is certainly biaxial, and in all probability belongs to one of the two inclined systems 

of crystallization, but its definite determination is not practicable under 

the circumstances." .

In view of the presence of an impurity in the new zeolite, Mr. Diller

suggested a reanalysis of it to be made on carefully purified materialThe purification, by means of Sonstadt's solution, he kindly undertook,

determining at the same time the specific gravity of th e mineral. The

Bull. 42 3 (33)
34 WASHINGTON LABORATORY. [BULL. 42.

crude material gave him a sp. gr. of 2.263j while the zeolite was a little 

lighter and the embedded grains were a little heavier. After purification the coarsely powdered zeolite was carefully picked over under the 

microscope until Mr. Diller felt confident that the sum of all impurities 

could not exceed 1 per cent. The mineral, then dried at 100°, gave 

me the following analytical results:

H30.,

Si02 . 

A1203 

CaO .

K20....................................................

99.85

These figures confirm the previous analyses ana show that the impurity which vitiated them must have been small in amount and similar in 

composition to the new zeolite. The latter, I think, may be considered 

as fairly well established, and its formula may be written Al3 (SiO4 ) 3 

Na2H,3H2O, which requires, water, 13.76; soda, 13.54; alumina, 33.41, 

and silica, 39.29. This composition and the manifest relations of the 

mineral to nephelite, the parent member of the group, naturally suggest 

for it the name hydronephelite, which seems to be both appropriate and 

descriptive. Chemically, as I have already observed, the species approximates to a soda thomsonite, but optically it appears to be quite 

different. This fact suggests the desirability of a careful microscopic 

re-examination of all the other massive zeolitic alterations of elseolite 

which, on analytical grounds, have been referred to the thomsonite series. Hydronephelite, indeed, is directly derived from sodalite, but the 

latter itself probably originated from ekeolite; so that the new species 

may quite properly be considered along with the other zeolites which

were previously mentioned. The fact that it contains more potassium 

than the sodalite is noteworthy and calls for an-explanation which I 

am unfortunately not prepared to offer.

ALBITE AND LEPIDOMELANE.

The albite of Litchfield, which appears to be associated with other 

undetermined feldspars, is mostly in obscure masses. Occasionally a 

fragment is found with a translucent cleavage surface one or two centimeters broad. Such a specimen was partially analyzed, giving H2O 

0.52, SiO2 66.39, A1 2O3 19.09, K2O 0.99, Ka2O 10.17. These figures serve 

only for complete identification of the species.

The lepidomelane exists abundantly in the elseolite rock, but mostly 

in small black scales. Sometimes tolerably large plates of it are found, 

black and brilliant, decidedly brittle, and apparently affected by altera-

(34)
CLAKKE.J MINERALS OF LITCHFIELD. 35

tion. An analysis gave the following results. The iron determinations 

were made by Mr. Biggs :

H2O ................................................... 4.62

F...................................................... None

Ti09 ................................................... None

SiO.................................................... 32.09

AljOs-................................................. 18.52

Fe3O3 .................................................. 19.49

FeO ................................................... 14.10

MnO................................................... 1.42

MgO................................................... 1.01

K20 .................................................. 8.12

................................................ 1.55

100.92

This analysis is noteworthy on account of the extremely low percentage of silica, which is approached, so far as I can ascertain, only in an 

analysis by Eammelsberg of a black mica from Brevig. The ratio between silicon and oxygen is nearly 1 to 5, which agrees with no known 

formula. My results make it extremely probable that the mica is a 

mixture and that it has undergone an alteration tending toward the 

ultimate development of some chloritic species. Still it deserves, as 

also do the feldspars of the locality, a more thorough examination,

DISCUSSION OF FORMULAE.

In attempting to discuss the formulae of cancrinite, sodalite, and hydrouephelite, certain points should be carefully borne in mind. First, 

the three species must be considered, not independently, but relatively 

to one another, for all the evidence indicates for them a common origin. 

That origin is from the first member of the group, elaeolite or nephelite, 

the empirical formula for which has been finally fixed by Banff.1 In 

partially rational form it may be written Na8Al8 (SiO4)7(SiO3 )2 , ignoring the small replacement of sodium by potassium, which has been shown 

by synthetic investigations to be non-essential. Not only does the mode 

of occurrence and association of the minerals point to community of 

origin, but the same conclusion is emphasized by the experiments of 

Lemberg 2 upon the artificial alteration of silicates. When elseolite from 

Fredriksvarn was digested one hundred and eighty hours with a solution of sodium carbonate, a partial transformation into a soda cancrinite 

was effected, while a digestion of six months with a caustic soda solution containing sodium chloride gave a product identical in composition 

with sodalite. Many such experiments were tried by Lemberg, yielding 

a large class of similar results. His method of procedure probably did 

not give absolutely pure or definite compounds, and yet his researches

1 Zeitsckr. Kryst. uud Mi a,, II, p. 445,

8 Zeitscliivcleutsch. geol. Gesell,, XXXV, p, 557,1883,

(35)
36 WASHINGTON LABORATORY. [BULL. 42.

furnish evidence of great value in discussing the chemical structure of 

many minerals.

The taking up of sodium chloride by elseolite, both in the dry and in 

the wet way, has also been observed by Koch. 1 The easy alterability of 

elseolite, therefore, may be regarded as a point thoroughly established 

and to be taken into account in all discussion of it and its congeners.

If we compare the published analyses of cancrinite from different localities we shall find that they vary in two ways. First, there are 

variations which are probably due to admixtures of elaeolite, such as I 

have shown to occur at Litchfield; and, secondly, the ratio between the 

lime and the carbonic acid ranges between rather wide limits. In the 

cancrinite from Miask, the two are about equivalent, while the Litchfield mineral contains only half enough calcium to saturate the carbonic 

acid. The lime and soda, however, vary reciprocally, so that when one 

is high the other is low; and, furthermore, the experiment quoted from 

Lemberg goes to show that a cancrinite may exist containing no lime 

whatever. If this conclusion be correct, then the carbonic acid of the 

mineral must be represented as linked with aluminum, a supposition 

which finds some justification in the existence of the rare species dawsonite. The function of water in cancrinite remains doubtful; if it be 

regarded as water of crystallization, the formula of the residue becomes 

less easy to write intelligibly; but, if it forms a part of the atomic structure, it is almost necessary to represent the carbonic acid as orthocarbonic in the group CO4 . This mode of consideration, as will appear 

later, leads to a simple general formula for cancrinite, covering all variations in composition except such as are due to impurity and correlating 

the mineral with the allied species sodalite andnosean. For the Litchfield mineral the following special formula may be written, giving the 

theoretical composition in the column below: Al8 (SiO4 ) 8 (CO4)2CaNa8H6 .

SiOa ...... ............

A1303 . ....... ..........

NaaO.... ..............

CaO ............ ......

COa ...... .............

H2O...... .............

Found.

35. 83 to 37. 22

28. 32 to 30. 12

19. 33 to 19. 56

4. 27 to 5. 12

6.22 to 6.96

2. 98 to 3. 86

Calculated.

or Q

30.6

18.6

4 2

6.6

4.1

100.0

In this case the water as found is slightly lower and the soda slightly 

higher than the calculated values, which is probably ascribable to. the 

mutual replaceability of sodium and hydrogen.

1 Neues Jahrb., Beil. Bd. I, p. 143, 1881. 

(36)
M.AHRH.] MINERALS OF LITCHFIELD. * . 37

The formula commonly accepted for socialite, and the one which is certainly the simplest, is that deduced by Barnberger ' from his analysis of 

the mineral from Tiahuaimco. Written empirically, this formula is Ka 5 

Al4 (SiO4 ) 4Cl, which requires considerably less chlorine- than has ordinarily been found in the species. In Bamberger's analysis, as finally 

corrected, he obtained 5.54 per cent, as against nearly 7 per cent, in 

Whitney's determinations. The difference he ascribes to silica in the 

chloride of silver, as weighed by other analysts ; and yet in my own estimation every 'care was taken to eliminate such impurity, and my results confirm the older figures. Still, both figures have theoretical interest, as will be seen further on ; and I am inclined to believe that the 

Bolivian mineral was more nearly typical than that from Litchfield. To 

the latter we may assign the empirical formula Na9Al7 (SiO4 )7Cl2, which 

is directly derivable from the formula for nephelite and which agrees 

quite sharply with the analyses.

We now have three empirical formulae ready for comparison side by 

side, as follows:

Nephelite... ................................. Al 8(Si04 )r(Si03 )2Na8

Cancrinite (Litchfield) ...................... Al g(Si04 )8(C04 )2CaNa8Hfl

Sodalite (Litchfield) ........................ AlT (Si04)7CliJNafl

These may easily be put into structural form by an application of the 

principle suggested in a former paper,2 that orthosilicates containing 

.aluminum are to be represented as substitution derivatives of the normal salt Al4 (SiO4 ) 3 . The latter contains the fundamental nucleus 

Al(SiO4 ) 3 , which appears to be capable of a sort of polymerization, and 

which forms the basis of the subjoined symbols :

Si03-Na Cl 

Si04=Al Al^Si04=Al 

Si04=Na2 Si04=Na<: Si04=Na2

si04=Al 

SiO4=NaH 

"

SiO4=Na2 Si04=Na2 i 

Si04=Al Al.^Si04=Al SiO,= NaH 

Si03-Na Cl Al^-Si04=Al

Si04=Na2

Nephelite. Sodalite. Cancrinite.

Now, although these formulae fit the analyses and express a structural 

similiarity of type, two of them are capable of a further generalization. 

Bemembering the reciprocal variations between soda and lime in different cancrinites and the fact that a soda cancrinite is quite pos1 Zeitschr. Kryst. und Min., V, p. 581.

^Topaz from Stoueham, Maine, Bull. U. S. Geol. Surv. No. 27.

(37) '
38 ' WASHINGTON LABORATORY. [BUM.. 42.

sible, we may write the following general formula for that species: 

A^fSiC^CC^NasHs; which requires

Si02 ...................................................... 35.8

A1203 .................................................... 30.4

Na2O (partly replaceable by CaO) ........................ 23.1

C02 ...................................................... 6.6

H2 0 ..................................................... 4.1

Comparing this with Bamberger's sodalite formula, and with the generally accepted formula for nosean, we have this remarkable series of 

structural expressions:

S04 Na Cl C04

i04=Al A1 ^Si04=Al Al<^Si04=Al

SiO4=Na.2 . Si04=Na2 ^Si04=Na

" \~ \ v

04=Na3 . . Si04=Na3 Si04; 

Noaean. Sodalite. Cancrinite.

The formula of hauynite of course reduces to the same type, and so also, 

probably, does that of microsoinmite. Hydronephelite has a still simpler formula, which, however, includes three molecules of water of crystallization. It may be advantageously compared in series with its 

parent minerals, in which case we have the following set of structures:

Si03-Na

;SiO4=Na2 .Cl.

Si04= Na 2 Si04= Na2 Al SiO4= Al 

4=Al Al^SiO4=Al NSi04=Al 

4=Na-2 Si04=Na3 +3 H2O 

4=Al 

3 Na 

Nephelite. . Sodalite. Hydronepbelite.

These formulae express with decided clearness the natural order of 

transition from one species to another. The alteration of a mineral 

necessarily involves the passage from a less stable to a more stable condition ; and in this instance we observe precisely that state of affairs. 

From a quite complex and therefore easily disturbed molecule, through 

an intermediate, simpler compound, we pass to one which is simplest of 

all, and hence presumably the most stable. I do not deny that such 

formulae are subject to criticism and that possibly the advance of knowledge may brush them to one side; and yet I feel justified in claiming 

that they have some real value in the co-ordination of observed facts, 

and that; through their singular suggestiveness, they assist in the prosecution of research.

(38)
TURQUOISE FROM NEW MEXICO.

BY F. W. CLARKE AND J. S. DILLER.

At Los Cerillos, New Mexico, about twenty-two miles southwest of 

Santa F6, are mines of turquoise which have been worked for centuries. 

The locality has been repeatedly described 1 from archaeological and 

geological points of view; but, so far as we are able to ascertain, the 

turquoise itself has never been fully analyzed, nor has it been subjected 

to complete microscopic study. Having at our disposal a very full 

suite of specimens, collected during the summer of 1885 by Maj. J. W. 

Powellr Director of the United States Geological Survey, we have 

thought it desirable to investigate the subject more thoroughly, and 

to present our results in such a form as to render them readily comparable with the published data concerning turquoise from other localities.

The turquoise occurs embedded in its matrix, sometimes in nodules, 

oftener in seams or veins. It varies in color very widely, ranging from 

a pure sky blue through many shades of bluish green and apple green 

to dark greens which show no blue whatever. The dark green nodules 

often shade off to nearly white at the center, sometimes resembling in 

structure, as Blake has observed, certain varieties of malachite. Many 

of the specimens are seamed or streaked by limpnite, which has been 

derived from accompanying pyrite; and the latter mineral occasionally 

is found, bright and unaltered, inclosed completely in masses of clear 

blue turquoise.

For analysis, three samples of turquoise were selected, representing, 

as nearly as possible, the most definite types of the mineral. They 

may be summarily described as follows :

A. Bright blue, faintly translucent in thin splinters.

B. Pale blue, with a slightly greenish cast, opaque and earthy in luster, 

and of sp. gr. 2.805. Blake giv es the density from 2.426 to 2.651 for 

the green variety.

C. Dark green, opaque.

i W. P. Blake, Am. Jour. Sci. (II), XXV, p. 227,1858. J. S. Nowberry, Report of the 

Exploring Expedition, from Santa Fe" to the Colorado, &c., 1859 (Macomb's Expedition). B. Silliman, jr., Am. Jour. Sci. (Ill), XXII1, p. 67,1881.

(39) 39
WASHINGTON

H3 0 ..........

A12 03 .........

Fe2 03 . ........ 

Pn

CuO ..........

SiO............

CaO ..........

A.

19.80

( 39. 53 

31.96

6.30

1.15

.13

98.87

B.

19; 60

36.88 

2.40 

32.86

7.51

.16

.38

99.79

C.

18.49

37.88 

4.07 

28.63

6.56

4.20

Uudet.

99. 83

Analysis A is not quite complete, for enough material could not 

be obtained without the destruction of too valuable specimens. The 

silica in it was due to traces of admixed rock, from w hich the material 

could not well be perfectly freed. C, however, was free from rock, and 

the silica in it must be accounted for otherwise. Silliman reports the 

turquoise as containing 3.81 of copper, which corresponds to 4.78 of CuO 

but he gives no other quantitative data.

In attempting to discuss these results, it will be well to compare them 

with three other published analyses of turquoise from difl'erent localities. >. 

First, we have the figures given by Church1 for the well known variety 

from Persia; secondly, the analysis by Gr. E. Moore3 of turquois e pseudomorphous after apatite, from Taylor's Eanch, Fresno County, California; 

and, thirdly, Nikolaieff's3 data concerning the mineral from Karalinsk 

in the Kirghiz Steppes. These analyses may be tabulated as follows:

HS 0.... ...........

A1203 -- -..-..--.-..

Fe2 03 .............

FeO......... ......

MnO .'.............

CuO ..............

P f)

Sp. gr...... .......

Persia.

iq -u

40.19

2.21

.36

5.27

32.86

100. 23 

2.75

California.

10 0(3

35. 98

2.99

7.80

33. 21

. 99.96 

2. 798, 2. 815

KarnliusK.

18.60

35.79

3.52

7.67

34.42

100. 00

These analyses, leaving temporarily out of account that of the dark 

green variety, agree well with one another in their atomic ratios. Divid1 Church, Chem.News, 10, p. 290; Dana'sSyst. Min.,p. 581. 

2 Zepharovich and Moore, Zeitsch. Kryst. und Min., 10, p. 240. 

sin a paper by Kokscharoff, Neues Jalirb., 1886, I, Ref., 10.

(40)
CUnka AND TURQUOISE F&OM NEW MEXICO. 41

ing the percentages by the proper molecular weights and treating the 

bases together, the following ratios appear :

New Mexico, A....

New Mexico, B ....

Total base.

.468

.479

.492

.470

.470

P20s.

.225

.231

.231

.234

.242

H20.

. 1. 100

1.089

1.075

1.110

1.033

In each case the base stands to the acid in a ratio very slightly in 

excess of two to oue, and that excess may fairly be accounted for upon 

the supposition that it represents a trifling admixture of limonite. The 

water is present in a proportion a little under that of five molecules to 

one of phosphoric acid, the variation here being due to differences

in the percentages of copper. If we calculate the amount of phosphoric 

acid necessary to satisfy the alumina and then reckon the phosphate so 

obtained as requiring five molecules of water, we shall have left over a 

quantity of copper, acid, and water corresponding to a very simple 

formula, and the turquoise will appear as a variable mixture of the two

following salts:

2 A12O3 , P2 05, 5 H20

2 CuO, P2 O5, 4 H2 O

In the Oalifornian turquoise the analytical results fit these formulas 

quite sharply and give the ratio between the two compounds as approximately four to oue. The first formula may be regarded as that of 

normal turquoise, and may be written in rational form, halved, as

A12HPO4 (OH)4

The copper salt, to which the mineral owes its color, is to be considered 

merely as an impurity, a Tiew which is emphasized by the analysis of 

the dark green turquoise 0. In the latter case the same ratios apply, 

modified by the presence of silica, which is nearly sufficient to form 

with the copper a normal rnetasilicate, similar to if not identical with 

chrysocolla. This silicate, with whatever blue tinge of color it might 

have, affected by the yellow or brown of the iron present, probably 

gives the turquoise its green hue. It is exceedingly probable that the 

purity of tint in gem turquoise is due to the copper salt alone and that 

degradations of the color towards green are ascribable to admixture 

of salts of iron. It is noteworthy that of the three turquoises analyzed 

the bluest contains the lowest percentage of copper. This could hardly 

be the case were not the colors of the other samples modified by some 

impurities, and compounds of iron would naturally produce an effect in 

the observed direction.

Sections of the three varieties of-turquoise were studied under the 

microscope and found to be of essentially the same character. Although

(41)
42 WASHINGTON LABORATORY.

deeply colored in the hand specimens, the thin sections appeared almost clear and transparent. Between crossed uicols the deep blue and 

green forms were seen to be composed of minute grains or short, thick 

fibers, but in the paler varieties the fibrous structure was more pronounced. The optical properties of both grains and fibers are the same 

throughout. They are all weakly doubly refracting, but have a rather 

high refractive index. The finely granular portions have a pale bluish 

aggregate polarization, less intense than that of chlorite, but when the 

mineral is distinctly fibrous it polarizes like some forms of serpentine 

with light colors of the first order. The fibers are generally somewhat 

bent and interwoven, but lie approximately in the same direction. 

Each fiber becomes dark when parallel to the principal section of either 

of the crossed nicols,- indicating that they must crystallize according to 

the quadratic, hexagonal, or rhombic system, instead of in one of the 

inclined systems, as was the case with the fibers studied by Bucking l 

in the turquoise of Fresno County, California.

A section was prepared of a distinct vein of pale green turquoise, 

which showed that the fibrous structure is directly across the vein perpendicularly to its walls. Small fissures, running into or across the 

veins, have the fibers of turquoise arranged perpendicularly along their 

sides, just as serpentine arranges itself along fissures in olivine. Some- , 

times the fissures are minute and curved; but the resulting arrangement does not simulate the radial fibrous or spherulitic structure described by Biicking 2 as found in the turquoise of California, Nevada, 

and elsewhere.

The perpendicular arrangement of the turquoise fibers along fissures, 

crossing the vein indicates that the mineral may have been derived 

from the alteration of another substance with which the vein was formerly filled. We would suppose, of course, that the original vein material was itself a phosphate 5 and the only one after which turquoise is

known to be pseudomorplious is apatite, a.species which not infrequently occurs in veins. The opinion that the turquoise has resulted 

from such an alteration is favored by the presence of other alteration 

products, to be noted in considering the composition of the country rock 

in which the turquoise is found. It is also suggested by Hermann's 

analysis of blue Oriental turquoise, in which the equivalent of 3.41 per 

cent, of calcium phosphate was actually determined. 3

The rock in which the veins of turquoise occur is described by Blake 

as/u a granular porphyry, yellowish, gray, or white in color, porous and 

earthy in texture. It decomposes rapidly by weathering and very much 

resembles a sandstone." In the collection made by Major Powell there

^ee paper by Zepharovich and Moore, Zeitschr, Kryst. und Min., 10, p. 240; already 

cited.

2 Zeitschr. Kryst. und Min., 2, p. 163. 

3 See Dana's Sysfc. Min.. p. 581.,

(42)
CT.AHKK AND Diujsn.]. TtfK'QUOlSE FROM NEW MEXICO. 43

are several good examples of the rock penetrated by the turquoise. It 

is a fine grained, reddish, feldspathic rock, mostly fresher than that 

described by Blake, and it has a micrograuitic aspect. It contains numerous particles of biotite and pyrite, with stainings of oxide of iron. 

The hand specimens look as though they had been crushed, and the 

fissures thus formed so filled as to produce irregular veins and nodules. 

The veins are small and mostly composed of turquoise, in which are 

embedded a few scales of biotite, particles of pyrite, and considerable 

quartz and oxide of iron. Scales of biotite are found abundantly in the 

iron stained cavities, as well as in the solid portions of the rock. Some 

specimens of rock, containing much pale blue turquoise of earthy texture, have been completely kaolinized, and a partial analysis of the 

kaolin gave the following results :

H2 0.. ................ .................................. 12.88

SiO-2 ........................................ ........... -52.38 .

AlsOs+FeaOs. ........................................... 33.49

P2 05 .................................................... None

MgO... .............v...... ............................. 1.17

CaO.......................................... .......... Trace

99.92

Although the mineral itself was white, the alumina from it was distinctly reddish with the iron.

Under the microscope the rock is seen to be composed chiefly of 

feldspar, with a considerable amount of biotite, epidote, pyrite, and 

limonite, and some amorphous substance. It is somewhat rnicrogranitic in structure, and the irregular interlocking grains of feldspar vary 

in size from .01 to .8mm in diameter. Most of them are considerably 

kaolinized, so as to appear cloudy in ordinary light; but between 

crossed nicols the original outlines of the grains become more distinct. 

Their optical properties indicate that the feldspar is orthoclase, an 

opinion which is fully borne out by the subjoined analysis of the rock, 

which shows a remarkably large proportion of potash :

HS0 .................................................... 3.28

SiO.2 ..................................................... 56.68

A12O3 ................................................... 16.62

Fe2O3 .......................................:........... 6.50 .

FzOs.............................................. ...... .73

MgO...!.......................... ...................... .79.

CaO ................................ .................... .59

CuO.............................................Trace, undet.

MnO......................I................................. 1.02

FeSj.................................................... 2.21

K2 0 ...!...................... ...... .................. 11.18

Na20.................................................... 1.03

100.63

The porphyritic crystals are generally Carlsbad twins with irregular 

outlines. There are occasionally small grains of fresh, transparent 

plagioclase. which has evidently resulted from alteration.

(43)
44 WASHINGTON LABORATOKY. [HUM, 4?.

The biotite of the rock occurs in noteworthy quantities, but is very 

unequally distributed. It is frequently aggregated in groups of scales 

and maybe seen most abundantly in small cavities. It sometimes occurs 

intimately associated with the turquoise, but unlike the latter it is one of 

the primary minerals. The small quantity of quartz present is a secondary product, so intimately associated with turquoise as to suggest their 

genetic connection. Pyrite is scattered rather uniformly throughout 

the rock in small cubical crystals easily seen in the hand specimen. 

They are sometimes altered to limonite, but in other cases they have 

been completely replaced by pseudomorphs of epidote. The specimen 

of rock which was subjected to analysis probably contained an amount 

of pyrite rather greater than the average.

One of the most important constituents of the rock, because of its 

very close association with the turquoise, occurs in the form of bright 

yellow grains. They are not distinctly pleochroic, but have a high refractive index, with strong double refraction, and give brilliant aggregate polarization. The particles are usually very small and grouped 

together in irregular compound grains, so as to suggest nothing of crystal lographic form. In several cases, however, elongated simple grains 

show inclined extinction, which indicates that the mineral must be 

either monoclinic or triclinic in crystallization. Judging not only from 

the properties enumerated, but also from the percentage of lime in the 

rock, this mineral is in all probability epidote. It is evidently connected genetically with the turquoise, for it is almost uniformly found 

upon the border of the latter and is most abundant in its neighborhood.

Concerning the origin of the turquoise bearing rock, it may be stated 

that Professors dewberry and Silliman, both of whom studied it in the 

field, regard it as eruptive and probably of Tertiary age. The occurrence of this veritable orthoclase rock in the West is of special interest 

from the fact disclosed by recent investigations that in many of the 

rocks previously described as trachytes the predominating feldspar is 

plagioclase.

The very small size of the veins and their limited distribution show 

that the turquoise is of local origin and emphasize the idea that it has 

resulted from the alteration of some other mineral. In addition to the 

evidence already cited to show that the turquoise has been derived from 

apatite, we have the fact that epidote, a lime bearing mineral, is present 

as a secondary product. The oxidation of pyrite may have had something to do with initiating the process of alteration and the alumina of 

the turquoise was probably derived from decomposing feldspar. The 

latter suggestion was made by Silliman, who also examined microscopic 

sections of the rock and reported apatite as present. No apatite, however, could be seen in the specimens examined by us. A search for it 

at the locality would certainly seem to be desirable.

(44)
THE GNEISS DUNYTE CONTACTS OF CORUNDUM. HILL, NORTH 

CAROLINA, IN RELATION TO THE ORIGIN OF CORUNDUM.

BY THOMAS M.'CHATAED.

Hie associations of corundum with the olivine or dunyte rocks of 

Western North Carolina and the adjacent portions of South Carolina 

and Georgia have been often described, 1 but, having had an opportunity during the summer of 1884 to visit a few of the typical localities 

and to collect specimens of the associated rocks, the results of my 

chemical examination of some of the latter are here given, as possibly 

affording some data for the solution of the problem of the origin of 

corundum.

The names given in this paper to the various rocks and minerals, 

unless analyses or authorities are given, must be considered as only 

approximately correct. By chlorite is meant all the varieties of green, 

foliated, hydrous, aluminous magnesian silicates met with in connection 

with dunyte, while the whole series of brown and yellow foliated minerals are called vermiculites. Under the heads of enstatite, talc, &c., 

are grouped a number of minerals of similar appearance, many of which 

may prove, on examination, to have compositions differing widely from 

that of the species under which they are placed.

In making the analyses, the silica, after being ignited over the blast 

lamp to constant weight, was treated with hydrofluoric acid and the 

residue deducted, while the alumina iron precipitate was, after ignition 

to constant weight, fused with sodic bisulphate, and silica, if present,

' C. U. Shepard, Am. Jour. Sci. (Ill), IV, pp. 109, 175,1872, 

J. L. Smith, Am. Jour. Sci. (Ill), VI, p. 180,1873. 

F. A. Genth, Am. Phil. Soc., Sept. 19, 1873, July 17,1874. 

J. P. Cooke, Proc. Am. Acad., Vol. IX, pp. 48, 49,1874. 

C. W. Jenks, Quar. Jour. Geol. Soc., XXX, pp. 303-306,1874. 

W. C. Kerr, Geol. N. C., I, p. 64, Supplement.

C. D. Smith, Geol. N. C., I, Appendix D, pp. 91-97; II, pp. 42,43, 1881. 

E. W. Raymond, Trans. Am. Inst. Min. Eng., VII, pp. 83-90, 1878. 

A. A. Julien, Proc. Bos. Soc. Nat. Hist., XXII, pp. 141-149, 1883. 

M. E. Wadsworth, Mem. Mus. Comp. -Zool., Litholcgical Studies, pp. 118, 119, 1884. 

T. S, Hunt, Trans. Eoy. Soc. Can., Vol. II, Sec. Ill, §§ 37, 38,1884. 

T. M. Chatard, Mineral Eesources U.,S., 1883-'84, pp. 714-720, U. S. Geol. Survey, 

Washington, 1885.

(45) 45
46 WASHINGTON LABORATOKY. [BULL. 41

separated. Double pre'cipitation was always employed and the precipitates were carefully tested.

THE LOCALITIES.

The principal southern mining localities for corundum are at Corundum Hill, Macon County, North Carolina, and at Laurel Creek, Georgia, 

26 miles southeast of the former. Both are owned and worked by the 

Harnpden Emery Company, under the direction of Dr. H. S. Lucas, to 

whom I am indebted for every desired facility and for a very warm and 

intelligent interest in my work. .

The two localities are alike in respect to the occurrence of the corundum. In both, the mineral is found in chlorite and vermiculite lying 

between hornblende gneiss and altered dunyte. At Laurel Creek the 

open cut in which the corundum is mined runs east 10°-20° north, following the course of the veins, the mine being situated on the north 

bank of Laurel Creek, at the base of a high hill. On the south bank 

and in the bed of the creek, hornblende gneiss is the country rock, succeeded as we go northwardly, by enstatite, talc, and allied minerals. The 

corundum first met with occurs in what is locally known as the "sand 

vein," which is composed of chlorite and vermiculite carrying more 

or less corundum, usually in small crystals and fragments. The chlorite 

in the upper portion of this vein was much disintegrated, the mass falling readily to pieces, allowing of the easy removal of the corundum, 

but at the time of my visit it was very compact and tough and of little 

value. The sand vein is succeeded by a so-called "horse" of steatite, 

on the other side of which is the vein of " block corundum." This is a 

vein of vermiculite containing masses of corundum sparingly mixed 

with chlorite and vermiculite and frequently of great size, several 

having been obtained of at least 5,000 pounds in weight. One mass 

which I saw must have weighed at least a ton. The north wall of the 

block vein is a smooth wall of "indurated talc" and steatite, which 

gradually passes into altered but still hard dunyte. Indeed, the difference between this place and Corundum Hill is in no respect more 

marked than in the greater hardness and toughness of the corundum 

bearing rocks and in the apparent concentration of the corundum into 

large masses with but little evidence of crystallization. At the westerly 

end of the cut is a vein of decomposed white material shown by analysis 

to be an altered soda lime feldspar. In this I did not find any corundum, but I was told that it was occasionally found in this rock.

The Corundum Hill mine is situated on a ridge which runs in the 

northeast and southwest direction characteristic of this section, the 

dunyte outcrops being on the crest, and apparently surrounded on all 

sides except towards the east by hornblende gneiss. On the east side 

mica schist1 takes the place of the gneiss, and it is on the eastern side

' Probably damourite schist; cf..Ara. Acad., 1874, by F. A. Geiith, "Damourite."

(46)
CHATAKP-] GNEISS DUNYTE CONTACTS OF CORQNDUM HILL. 47

of the dunyte that the so-called " sand vein " is found. This is a veinlike mass of brown vermiculite in small scales containing an abundance 

of small crystals of corundum, which are usually brown in color and often 

broken into fragments. At the time of my visit the nearly perpendicular vein was about 6 feet wide and was worked by hydraulic washing 

through an open cut about 30 feet deep. The easterly wall of this 

vein is the mica schist very much decomposed, while on the western 

side we find enstatite, next vermiculite mixed with chlorite, then talc 

which in turn gives place to nodules of more or less altered dunyte.

The specimens of corundum crystals for which this locality is so celebrated have all been found on the westerly side of the dunyte, and, so 

far as I have seen or could find out by inquiry from the owners and the 

miners, only on or near the lines of contact between the gneiss and the 

dunyte. The dunyte is sometimes, as stated by Julien in the paper 

cited," interbedded with the hornblende gneiss in layers 1 to 6 meters

in thickness. This was shown by a cross section of the beds on the 

north side of the dunyte deposit at the Jenks Mine (Corundum Hill), 

near Franklin, in Macon County. Although the dunyte is thus inclosed in or interbedded with the hornblende .gneiss, the latter was 

never observed to be enveloped by the dunyte."

The origin of the dunyte, whether igneous or sedimentary, and, if the 

latter, whether mechanical or chemical, is a disputed question which 

has been ably discussed in the list of papers already given, and upon 

this point I am not able to give any further information of value. 

Leaving out the question of the origin of the dunyte, it appears very 

much like a dike or dike series, portions of which have been forced into 

the adjacent country rock without completely severing the connection 

with the main mass.

In its present condition it forms irregular spheroidal masses,-sometimes several meters in diameter, most of which are much fractured and 

altered, the fracture seams being filled in with brown or yellow, clay-like, 

magnesian silicates, while the surface is also converted into a similar 

material which, when dry, has a strong tendency to peel off in semiconchoidal plates. In this form of alteration the mass of the nodule is still 

rather hard, but frequently the nodules are cased with talc, 10-20cm 

in thickness and quite tough; when, however, this casing is pierced 

throughj the interior is found to consist of a soft, yellow, ocherous material, into which a rod can be forced with comparative ease for a foot or 

more; towards the center of the nodule the material is often harder, 

being apparently less thoroughly decomposed.

The gneiss along the lines of contact is much decomposed, preserving 

its laminated structure but becoming a friable mass of reddish and 

brownish gray grains of quartz and scales of altered mica, with whitish 

nodules irregularly disseminated through it. Several contact sections 

from gneiss to dunyte were examined, and samples taken as the charac-

(47)
48 WASHINGTON LABOKATOKY. [BULL. 42.

terof the formation seemed to change. Of these the results of the chemical examination of one series is given, as it is typical of them all, the 

variations in the others being due, apparently, only to differences in 

the relative proportions of the same general classes of minerals.

DESCRIPTION OF THE SECTIONS.

These sections were all taken in an open cut which starts from a point 

near the corundum mill and runs into the hill in a southeast direction. 

In this cut the exposures were clearest, the banks in most of the other 

cuts being more or less covered, either by caving or by debris piled 

against them in the course of the mining operations.

In going up the cut the walls were found to consist in most part of 

the material which I have called altered gneiss, with occasional masses 

of dunyte very much altered and showing the characteristic chloritic 

minerals. The cut at the upper end widens out immediately after 

passing through a belt of gneiss which crosses it with a northeast, southwest strike and a dip which is apparently eastward, but is nearly perpendicular. This rock can be traced northeast for some distance, but is 

then covered by mining debris, though Dr. Lucas informed me that it 

continued without an apparent break through that portion of the ground. 

Beyond the rock piles it can be traced to the main body in the higher 

part of the hill.

On the east side of this gneiss and on the north side of the cut we have 

the following sequence:

Section A.

A 1. Altered gneiss, becoming somewhat vermiculitic as it approaches A 2.

A 2. A narrow band of greenish chlorite.

A 3. A 6 inch seam of vermiculite.

A 4, Soft, yellow, magnesian clay.

A 5. A narrow seam of very impure chalcedony; stained red.

A 6. More yellow clay.

A 7. A rather hard casing, brownish yellow in color, inclosing

A 8. A large nodule of dunyte, much altered, with seams filled with soft clay and 

harder material of the same kind, while the comparatively hard brown yellow dunyte (A 8) has running through it small seams of

A 9. A mineral similar to enstatite.

Section B.

On the opposite side of the cut a section, B, starting from the same 

gneiss, shows 

B 1. Altered gneiss, like A 1.

B 2. About 2 feet (G0cm) of yellowish, micaceous, and quite rotten material. 

B 3. About 30cm of fine, scaly, brown vermiculite.

B 4. A band of foliated, compact, bright green chlorite stained bright red in places 

with ferric oxide or an iron clay.

(48)
CHATAKD.I GNEISS DUNYTE CONTACTS OF CORUNDUM HILL. 49

B 5. Eustatite. gray in color and quite hard. 

B 6. Yellow clay similar to A 6, and inclosing

B 7, Much altered but still rather hard dunyte, the casing on the other side being 

chlorite.

The corundum, when it occurs, is found in A 3 and B 3 and is much 

fractured.

Section C.

At about 10 meters northeast from A the Section 0 was made and 

gave the following series:

C 1. Altered gneiss, containing, distributed irregularly through it,

C 2. Harder nodules, very silicious; the gneiss gradually changing into

C 3. A scaly, brownish material, followed by

C 4. A soft, friable, yellowish white kaolin, intermixed with

C 5. A reddish brown, micaceous mineral, followed by

C 6. A seam of a small foliated, brownish yellow mineral which disintegrates easily, 

falling into small scales.

C 7. Vermiculite containing corundum. The specimen selected for examination was 

very typical and showed a mass of friable, yellowish brown vermiculite with a 

narrow seam of bright green chlorite dhiding it into two nearly equal 

parts. The corundum is found on only one side of this chlorite seam, but is 

there in large proportion, some of the crystals being over 2cra in length; 

the width of the corundum bearing streak being about 15cm . The vermiculite containing the corundum was marked C 7 a ; that on the other side 

of the chlorite, and which showed no corundum, C 7 /?. This was followed by

C 8. A combination of vermiculite and actinolite.

C 9. Enstatite mixed with chlorite, forming a tough casing about 10cin thick, inclosing a mass of altered dunyte with the yellow ochers and other characteristic decomposition products.

In giving the results of the examinations of these minerals it may be 

well to say that the rocks were always examined carefully with a strong 

lens and in most cases microscopically. The separations were made 

with Sonstadt's solution whenever practicable; but in the presence of 

the slimy, yellow, magnesian silicates this was often impossible, and 

hand picking was resorted to.

ANALYTICAL RESULTS.

C 1. Altered gneiss (*?). A friable, sublaminated aggregate of scales of 

a micaceous mineral, in color from colorless to brownish and reddish 

yellow, with grains of quartz of similar shades of color and occasional 

small masses of a whitish, kaolin-like material (C 2). This rock has, as 

stated above, the same strike, dip. and structure as the adjacent unaltered gneiss and apparently passes into it.

C 2. Nodule in C 1. Structure finely granular, with larger grains of 

quartz disseminated through the mass, and a few small, yellowish scales 

on the fracture surfaces; rather friable; color brownish and yellowish 

white, with some small brown spots.

C 3. A friable aggregate of micaceous minerals, similar in structure 

and appearance to C 1, but the scales are smaller and more deeply colBull. 42 4 (49)
50 WASHINGTON LABOKATORY. [BULL. 42.

ored in shades of brown and yellow, tbe grains of quartz are fewer and 

smaller, and the nodules C 2 are absent. '

Ignition ........ . 

Si02 . ..............

TiOs ............

P205 . ...........

A1203 ..............

FejOs ...........

FeO. ..............

MnO ..............

CaO. ..............

MgO. .............. O

K2o ........:......

NaoO ..............

Cl.

4.97 

64.27

1.32

0.05

16.75

6.08

0.89

0.07

0.25

1.74

3.09

0.89

100. 37

C2.

2.79 

75.62

12. 52

2 52

0.56

0.42

'5.58

0.27

100. 28

C3.

7.96 

56.65

0.44

T; a o

21. 60

6.36

0.70

0.13

0.35

3.61

1.98

0.59

100. 37

C 4. Soft, friable, fine granular, yellowish white, kaolin-like material, 

in lumps, with dark brown spots and streaks. Contains a very small 

proportion of fine grains of quartz.

C 5. The lumps of C 4 are scattered through a seam of a small foliated 

mineral aggregated to a loosely coherent mass which breaks up when 

handled. The scales have a pearly luster and are apparently colorless 

or of a greenish tint, but are stained reddish brown by interlaminated 

ferric oxide whichcanuot be separated from them. When heated the 

mineral exfoliates slightly, assuming a silvery luster and a purplish red 

color. Before ignition, decomposable by hot, concentrated hydrochloric 

acid. . C 6. A compact mass of translucent scales; color, yellow with shades 

of brown; apparently homogeneous, but altered; disintegrates easilyj 

contains a little chromite (0.15 per cent.).

SiOs-.- ........

A1203 -. ........

Cr203 .........

FeaOs

FeO...........

MuO ..........

CaO........... 

MgO..........

C 4.

13.70

45. 71 

35.49

1.82

0.60

0.06

0.30 

1.61

0.34

99. 63

C 5.

12.63

37.96 

22.53

11 12

0.30

0.12

None 

15.46

Undet.

100. 12

C 6.

9.46

52.59

K Ofi

0 *&

2

OO

0.69

0 19

0.33 

28.53

0. 16.

99.99
GNEISS DUNYTE. CONTACTS OF CORUNDUM HILL.

C 7 a and C 7 /3. This occurrence has been described above. The 

two vermiculites show but little difference in physical characteristics, 

both being fine, scaly, and of a pale brown yellow color. The thinnest 

scales have a pearly luster and are nearly transparent. C 7 a was 

carefully hand picked and showed no corundum under a magnifying 

glass, but the presence of it was shown not only in the course of the 

analysis, but also in the process of grinding, as the vermiculite when 

pure is quite soft and free from grit. The corundum is probably interlaminated with the vermiculite, as is often seen in specimens which are 

more broadly foliated j 1 moreover the corundum crystals, as separated 

from the gangue, are very much fractured and fall readily to pieces, 

often forming thin plates. C 7 /? appears to be free from corundum. 

The analyses are given with total amount of water and are also calculated as being free from corundum and dried at 110°, the latter calculation showing that the two vermiculites are practically identical,

The narrow seam of chlorite separating these two was not examined 

chemically, as it did not differ apparently from the ordinary chlorites 

of this region. One chlorite (Analysis F, see page 56) has been examined on account of its peculiar appearance, but in most cases it was not 

deemed necessary:

H2OatllO°.... 

H20 at red heat. 

Si03 . ..........

Alo03 ..........

Fe203 .. .--.....

Fpf)

MnO. ..........

CaO ...........

MgO. ..........

C

Air dried.

8.87

10.33 

9.47 

31.01

15.14

5.63

0.55

0.12

0.35

19.08

0.22

100. 77

7 a.

At 110°.

11.60. 

38.02

18.56

6.90

0.68

0.15

0.44

23.38

0.27

100. 00

C 7

Air dried.

11.42 

10.05 

32.97

17.88

4.76

0.57

Trace

22.36

100. 01

P.

At 110°.

11.34

37.22

20.19

5.37

0.64

25 24

100. 00

C 8. A mass of a yellowish brown, small foliated mineral, through the 

central part of which runs an irregular seam of a fine, granular, grass 

green mineral intermixed with a small quantity of black magnetic 

grains and a large proportion of the vermiculite scales, which are, however, much smaller than those of the outer portions. As there were cons, quoted by Cooke, Proc. Am. Acad., 1874, loc. cit.j Genth, Am. Phil. Soc.

Sept. 19, 1873, section Chlorite;

(51)
52 WASHINGTON LABORATORY. [BULL. 42.

siderable differences in the specific gravity of these minerals, they were 

separated by Thoulet's solution and marked C 8 a, C 8 /?, and C 8 y.

C 8 a. Small rounded grains showing some octahedral faces ; opaque; 

luster, submetallic; color, brownish black; streak, blackish brown; magnetic. Analysis corresponds to chromite intermixed with some magnetite, but FeO was not determined for itself, the whole of the Fe2O3 

being calculated as such.

C 8 fi. Finely granular, compact, the larger pieces showing under 

the magnifying glass a crystalline structure and longitudinal striations; 

translucent to subtransparent; luster, vitreous; color, grass green; 

streak, greenish white; sp. gr., 3.062. Analysis corresponds to actinolite.

H20at 110° ...........................

Si02 . ...... .............................

Ti02 ...................................

PS06 ...... ..............................

Cr3O3 . -- -.. .........-.............:...

A1303 . ....... ..........................

Fe203 ..................................

.FeO ...........:........................

(Ni,Co)O .................... ..........

MnO ...................................

CaO... ......................,....;....

MgO ..................................

08 a.

q on

0.36

n 10

45 94

0 C1

4° Qfl

0.84

 3 Q1

99.78

C8/5.

0.04

O r.n

2KC OQ

0 1Q

|3.04

1 fiS

2

C1

TTO /it*

0.26

10 Of*

99 °»1

0.58

99.92

C 8 y. Foliated, compact; folia generally small, not over 2mm across; 

cleavage, basal, eminent; color, yellowish brown, the thinnest scales 

being almost colorless, with a greenish tint; luster, submetallic, somewhat greasy, the material having a great resemblance to the so-called 

"bronze powder." Easily decomposed by concentrated hydrochloric 

acid, the silicic acid separating in pearly scales. When heated gives 

off much water and exfoliates with considerable force, particles being 

projected several centimeters from the mass, which doubles its bulk 

and becomes reddish brown with a somewhat silvery luster. Examined 

microscopically by Mr. J. S. Diller, who reports " that it is biaxial and 

negative, but the angle between the optic axes, as seen in a cleavage 

plate split off parallel to the base, is uniformly small. Upon rotating 

the section, although the cross is plainly distorted into two hyperbola, 

they do not completely separate from each other/ 7 Sp. gr., 2.613 in 

water at 25.5°. 

(62)
ciiAi'AHD.1 GNEISS DUNYTE CONTACTS OF CORUNDUM HILL. 53

In the following water determinations the figures in brackets represent 

determinations by difference, the others being direct determinations.

H3 0 at 110°. .............

H2 6 at 130°. .............

H2O at red heat (blast 

lamp) ............. ....

Total H2 0 as deterPer cent.

3.87

0.12

(6. 83)

10.82

Per cent.

3.81

j> 7.04 

J

(10.85)

Per cent.

3.72

(G. 95)

10.67 '

Per cent.

3.72

(7.00)

10.72

Average.

3.78

' (6.98)

10. 76

Analyses Nos. 1 and 2 are the results obtained on the air dried mineral; No. 3j average of 1 and 2, and No. 4 the average calculated as dried 

at 110°. ' ' '

H2OatllO° ..................

H20 at 130° and red heat 

Si02 .. ........................

Ala03 .................. ......

Cr203 .. .......... .............

Fe2 03 ........................

FeO...... .....................

MnO.. ....................:...

CaO.... ......................

MgO...... ....................

ZsO. .........................

NasO... ......................

l.

3.78

6. 98 , 

39. 89

12.88^

0. 54 1

5 29 >= 18,82-

O.llJ

0.05

0.14

24. 88

5.76

0.20

100. 50

2.

' ft "7!^

(6. 98) 

39.74

19. 04'

0.05

0.13

24.78

(5.76)

(0. 20)

100. 46

3.

3.78

6.98 

39.81

C 12. 99

1 0.54

| 5. 29

1 0.11

0.05

o;i4

24.83

5.76

0.20

100. 48

4.

7. 22 

41. 17

13. 43

0.56

5.47

0.11

0.05

0.14

25.68

5.96

0.21

100. 00

No. 4 gives the atomic ratio :

Si : B : E : B : H

2.75 :1.03 :fc29: 0.14: 0.80

2.46

6

:0.80 

: 2

As this mineral appears to be a very definite vermiculitej I have, 

in order to distinguish it from the others, given it the name lucasite, in 

honor of Dr. H. S. Lucas, of Corundum Hill, North Carolina, and the

"(53)
54 WASHINGTON LABORATORY. twuuui

following table froih Professor Cooke's paper1 will show its relations to 

the other members of the group at 100°.

Hallite ........ 2.42: 2.41 :1.47 or 8: 8:5

"Lerni"....... 2.54: 2.50 : 1.30 or 2 : 2 : 1

Pelhamito...... 2.75: 2.46 : 1.26 or 9 : 8 : 4

Culsageeite .... 2.50 : 2.66 :1.23 or 2 : 2 :1

"Millbury".... 2.38: 2.74 :l.l4or2:2:l

Jefferisite...... 2.56: 2.53 : 1.17 or 9 : 9 : 4

Lucasite....... 2.75: 2.46 v : 0.80 or 7 : 6:2

C 9. Grayish white, asbestiform mass made up of fine fibers of a vitreous luster, aggregated to a somewhat woolly mass intermixed with a 

smaller proportion of bright green chlorite. The rock mass disintegrates 

easily, breaking down into a soft, woolly aggregate of fine needles, not 

folia. A hydrous enstatite. Sp. gr., 2.872.

H,0 ..................................................... 4.55

SiOi ...................;............-.................... 56.58

TiO2 ..........................i......................... None

Cr2O3 ..........................................-.....-.- 0.24

A1203 ..................................................... 1.74

Fe2O3 ....... ............................................ 1.89

FeO.................................................... 3.67

MnO ........... .,,...................................... 0.21

CaO.................................................... 0.59

MgO.................................................... 30.34

Alkalies ................................................ 0.17

99.98

fhe dunyte alteration following C 9 was very much decomposed, being 

a friable, Clay-like mass with needles of white, hydrous enstatite, like 

C 9, and small scales of another mineral which, however, could not be 

separated in a pure condition by means of Sonstadt's solution, as almost 

all the scales showed, when examined under the microscope, that they 

were interpenetrated by the needles. The examination of the decomposed dunyte of the A series will, however, show the character of these 

alteration products.

Of the following analyses, D is from the apparently least altered 

specimen of dunyte that I was able to find. It is granular, crystalline, 

the grains of olivine being subtranslucent, with a subvitreous luster and 

of an oil green color with grayish tints. The rock contains a little chromite.

Some of the specimens of dunyte, particularly the darker varieties, 

show an indistinct radiated structure, the radiations starting from points 

which are lighter in color than the rest of the specimen*

1 Cooke, Proc. Am. Acad., p. 461,1875, 

(54)
CHATAUD.] GNEISS DUNYTU CONTACTS OF COEUNDUM HILL. 55

E is my old analysis of dunyte from the same locality, given in Dr. 

Grenth's first paper on corundum, already cited.

Chromite ................ 

H2O.. ...... .............

SiOa . ....................

Cr203 ....................

A1303 .. ..................

Fe2O3 ...................

FeO ....................

NiO(tr. CoandMu) .....

CaO. ....................

MgO. ....................

D.

0.56 

2 74

40.11

0.18

0.88

1.20

6.09

48.58

100. 34

E.

1.72

41.53

0.14

7.49

0.34

0.11

49.28

100. 66

A 7 is the casing of the dunyte nodule of the A series. It is brownish 

yellow, granular, and, when dry, easily pulverized ; but, some portions 

appearing harder than the rest, the specimen was crushed without 

grinding, the coarse powder shaken violently and then sifted through 

a fine sieve. The softer part was called A 7 a, the harder A 7 /?, and 

it will be seen that the two are practically alike, the harder part 

containing much more chromite and being not quite so much decomposed.

Chromite-.-. 

Ignition .... 

Si02 . ........

A1 B03 . ...:...

FesO, -.-- - 

MgO. .......

A 7 a.

0.17 

2.14 

40.04

3. 17

12.15

42.97

100. 64

A 7 ft.

2.45 

2.01 

40.18

1.35

9.88

43.84

99.71

A 8. Altered dunyte, granular, compact, traversed by small seams 

carrying A 9. Luster, dull; color, pale yellowish brown. From interior of nodule.

A 9. Fine fibrous or small foliated, the folia being so arranged transversely in the seams of A 8 as to present a fibrous appearance. Luster, 

pearly soft; color, colorless to white. Subtranslucent.

(55)
56 WASHINGTON LABORATORY. [BULL.

F. Chlorite; broad foliated, folia brittle, being probably somewhat 

altered. Colorr dark bluish green ; luster, submetallic. From Corundum Hill'.

-H20.. .........

SiOs ...........

A1 3 03 . .........

Fe2 03 .........

FeO.. .........

CaO.. .........

MgO ..........

KaO... ........

A 8.

1.54

40.25

0.96

2.71

5.97

47.76

99.19

A 9.

4.32

56.39

2.31

0.16

1.96

0.04

34.57

99.75

F.

12.71

35.88

20.90

6.55

3.68

0.14

19.90

0.19

99.95

In comparing these analyses with reference to the mode of occurrence 

of the corundum and to the question of its probable origin, it must be 

remembered that we start from an aluminous rock, gneiss, on one side 

of the seam, and, passing through the series, reach as a final term a 

magnesian rock, dunyte. In following the series we should expect to. 

find a progressive increase in the amount of magnesia and a gradual 

decrease in the amount of alumina. It will be observed that such is the 

case with the magnesia, while, roughly speaking, it is also true of the 

alumina. The ease with which magnesia, in the processes of rock alteration, may be dissolved and redeposited explains the regularity of its 

increase, while the high degree of insolubility of silicate of alumina and 

the presence of varying quantities of kaolin in the specimens C 1 to C 6 

account for the irregularities in the alumina percentages. The members 

of .the series C1 to C 6, though crystalline, ar'e in nearly every case much

decomposed and do not allow, generally, of proper.separations. Enough 

has been done, however, to show that the entire series falls into three 

groups: aluminous silicates, alumino-magnesian silicates,and magnesian 

silicates. The list of constituents is practically the same for all, and it 

is only by considering the relative predominance of one or the other 

base that the distinction can be made. The middle term of the chemical series is also the middle term of the field series, and in it the corundum is found. All the gneiss dunyte contacts which I have seen or 

have information of give practically the same succession. Corundum 

is, however, only an accessory; frequently it is not found at all, and, 

when present, often in comparatively small quantities. It may therefore be considered as the result of a certain balance between the aluminous and the magnesian solutions, which have by their union produced 

the chlorites and the vermiculites.

The question of the origin of the dunyte, in so far as it has any reference to that of the corundum, can now be considered. Three modes of

(56)
CIIATARD.J GNEISS DUNYTE CONTACTS OF CORUNDUM HILL. 57

origin are supposable, chemical, sedimentary, and igneous. If a chemical 

origin be assigned to the duny te (and gneiss), we could have a sequence 

of events something like the following: An aluminous silicate solution 

depositing the constituents of gneiss gradually becomes .impregnated 

with a solution of magnesia either as silicate, or, more probably ^ a mixture of silicate and carbonate. The researches of Way1 and those of 

Deville, Friedel and Sarrasin, and de Schulten* have shown that aluminous silicates and alkaline silicates can be made to combine, forming feldspars and other alkaline-aluminous silicates, and Way showed that the 

alkali could be replaced by lime.

Although much more work is required in this direction, still we are 

warranted in assuming that, if we can obtain solutions of aluminous 

silicates and of magnesian silicates and allow them to react upon each 

other under proper conditions, we shall obtain hydrous-alumino-magnesian silicates, or if iron be present, as is the case with dunyte, silicates belonging to the chlorite and vermiculite groups.

Under this assumption, the rock forming solution would cease depositing the constituents of gneiss, even of the more hornblendic varie- 

, ties, and, instead, furnish chlorites and allied minerals, until, gradually 

becoming more and more magnesian, enstatites, talcs, and finally chrys- 

. olites would be the products. To account for the formation of corundum during this process we must suppose the presence of carbonate of 

magnesia along with the silicate, which would permit of the replacement, by magnesia, of a part of the alumina, which would be precipitated either as the hydrate or, under conditions as yet unknown, as 

corundum.

If instead of a chemical origin for the gneiss and dunyte we consider 

them as results of either a sedimentary or an igneous action, we shall find 

the reactions involved in the alterations of these rocks to be of' the 

same character. In either case we should have gneiss in contact with 

dunyte. As soon as alteration of the gneiss begins, the feldspar kaolinizes and the mica is attacked, yielding solutions of alkaline salts which 

have the property of dissolving alumina, and this action is increased 

by the presence of carbonic acid, while even solutions of iron silicates 

and magnesian silicates have the same effect.3

As Both observes, accurate and sufficient data are lacking for the 

proper consideration of such questions, but enough is known to be able 

to say that the alteration of gneiss or granite furnishes a solution of 

silicate of alumina. On the other hand, the mode of alteration of olivine has been studied, 4 and we know that both magnesia and silica are 

removed, the former in excess and therefore probably as carbonate,

1 Way quoted by Hunt, op. cit., § 97.

2 Hunt, op.cit., $$ 98-99. Fouque" et Le"vy, Syuthese des mine"raux et des roclies, 

pp.32, 134, 161-164, Paris, 1882.

;! Roth, Chem. Geol., Vol. I, pp. 112, 141-160, 305-334, Berlin, 1879. 

 Roth, Chem. Geol., p. 113. . ' 

(57)
58 WASHINGTON LABORATORY* IBULL. 42.

which, as such, is not an uncommon occurrence among these rocks. 

Iron would, of course, be dissolved in the same manner as magnesia. 

Julien, in his paper already cited, says (page 147):

Thei corundum itself is in all cases, both in the veins and in the particles found 

in the gabbro, a secondary or alteration product. All the phenomena of alteration, 

both in the veins and rock masses, absolutely require and can be simply explained 

by the introduction of a solution of soda and alumina into the fissures and interstices 

during the period of alteration and metamorphism. The combination of soda with 

silicates of alumina and iron, perhaps previously formed, has produced all the minerals of the vein series; while the precipitation of the alumina naturally ensued 

from the separation of its alkaline solvent. The question then presents itself of the 

evidence of the introduction of such a solution. This is found in the strata of 

hornblende gneiss, which everywhere surround the dunyte beds and are abundantly 

traversed all along the dunyte belt by huge veins of endogenous granite. Into these 

there has certainly been an introduction, by subterraneous thermal solutions, of soda 

and alumina, as shown both by the development of a long series of crystallized mineral silicates containing those bases with other elements, and, elsewhere, even by the 

precipitation of corundum itself (in association with muscovite, margarite, and 

albite) in a certain class of small veins in the gneiss of limited occurrence but of great 

interest.

Professor Julien's extended field experience among these rocks gives 

great weight to his opinion that corundum is a product of rock alteration. It is, indeed, difficult to see how a different opinion can be arrived at, if these rocks are studied in the field. In my own case, my 

field notes, written before I had an opportunity to see his valuable paper, indicate the same conclusion. Whether the solutions of soda and 

alumina must be heated in order to effect the production of these minerals is a question to which, at present, no definite answer can be given j 

but it would seem that the ordinary subaerial decay of these rocks should 

furnish the necessary solutions. The observations of Becker and the 

experiments of Barus1 show that there is considerable doubt as to any 

production of heat as a result of the kaolinization of feldspar, and if 

Such is the case with feldspar it is not likely that the alteration of any 

of the other mineral species present in these rocks would be attended 

by any marked rise iii temperature.- We must therefore conclude that 

the gneiss can furnish an alkaline solution of alumina and the dunyte 

a solution of magnesia without the production of heat and perhaps 

without its aid. Unless heat be absolutely necessary, either for the pro 

duction of these solutions or for the formation of the contact minerals, 

we have no need for the introduction from a deeper source of a heated 

solution of alumina and soda, as the solutions furnished by the rocks 

at the contact should be sufficient for the purpose^ and, by their meeting 

at the contact of the formations, give rise to the reactions stated above, 

namely, the production of chlorites and vermiculites, and, if the necessary conditions of proportion are reached, of alumina or corundum. 

That these conditions are often lacking is shown by the comparative

1 G. P. Becker, Geol. of Gomstock Lode, Mon. U. S. Geol. Surv., Vol. Ill, Chaps. 

VII and IX.

(58)
GNEISS DUNYTE CONTACTS OF CORUNDUM HILL. 59

rarity of the occurrences of corundum when the number of such chlorite bearing contacts is considered.

Among the miners chlorite or vermiculite is considered a " corundum 

sign," and they follow it as long as it holds out. "The chlorite veins often 

extend for some distance into the dunyte, as should be expected when 

we consider the thoroughly fractured condition of the dunyte, with its 

consequent spheroidal alteration forms; but, in such cases, the connection with the contact can generally be traced. In. the same manner the 

chlorite seams may extend into the gneiss.

It has already been said that the dunyte of Corundum Hill lies between hornblende gneiss and mica schist. The same can be said of the 

locality at Unionville, Chester County, Pennsylvania, and, to a certain extent, of that at Chester, Massachusetts.

Mr. W. W. Jefferis has kindly furnished me with much information 

about the former place, where the serpentine (probably resulting, as 

stated by Genth, 1 from the alteration of chrysolite rocks) lies between 

mica schist on the north and hornblende gneiss on the south. The 

great mass of corundum which was found at this place lay on the 

north side, in the serpentine, a short distance from the mica schist, and 

was accompanied by chlorite. " It was between well defined walls of 

serpentine" (Jefferis). At a point on the south side of the serpentine, 

at the contact with the hornblende gneiss, is " a digging 15 feet deep, 

which produced 500 pounds of extra fine, blue corundum, similar to the 

blue from Macon County, North Carolina. Culsageeite occurs here iden. 

tical with the North Carolina specimens. Both the corundum and the 

culsageeite are so much like the Carolina mineral that it is difficult to 

tell them apart" (Jefferis).

The deposit at Chester, Mass., is a vein of emery situated nearly in 

the center of the Green Mountain chain.

It is included in the metamorphic series of rocks, here consisting of 

vast breadths of gneiss and mica slate, with considerable interpolations 

of talcose slate and serpentine. Strike, N. 20° E.-S. 20° W.; dip from 

vertical to 75°-80°, sometimes east, sometimes west. The immediate 

vicinity of the mine presents a succession of lengthened rocky swells, 

the longer axis of the elevations generally coinciding with the direction of the strata.

The emery vein traverses, in an unbroken line, the crests of two of 

these adjacent mountains, and is about 4 miles long and about 4 feet 

wide. It lies at the junction of the gneiss with the mica slate, just 

within the western edge of the gneiss, having throughout a layer of 

gneiss 4 to 10 feet in thickness for its eastern wall. Between this layer 

of gneiss and the mica slate is talcose slate about 20 feet thick at. the 

south end and widening out at the northern end to nearly 200 feet.

i Genth, Am. Jour. Sci. (II), XXXIII, p. 202, 1862, 

(59)
60 WASHINGTON LABORATORY. [HULL42.

The gneiss is highly horubleiidic; where hornblende is rare, epidote 

is found. Quartz is very deficient and no corundum is found in the 

gneiss. The talcose slate carries soapstone, chlorite, talcose dolomite, 

&c., and contains, here and there, corundum. Quartz is very rare. In 

the vein are found corundum, magnetite, margarite, ripidolite, biotite, 

andestite, tourmaline, and titaniferous iron. 1

Whether or not this locality can be placed with those already described is a question to which, not having visited the mine, I cannot 

give an answer. There are many points of similarity, but the presence 

of the thin wall of gneiss on the eastern side of the vein brings a difficulty into the consideration of the problem. The presence of magnet-. 

ite must also be explained; and, as the action of lime is here evident, 

it may be that this occurrence must be placed with that of the Cullakenee or Buck Creek Mine, Clay County, North Carolina, where lime 

has also played a part, as shown by the presence of margarite, zoisite, 

and oligoclase, the last carrying corundum.

The action of lime brings us to the occurrences of corundum in crystallized limestone, of which the emery deposits of Asia Minor and the 

Greek Islands, studied by J. L. Smith,2 are the most important. In his 

memoir he says:

In every instance I have found the emery associated with the old limestones overlying mica slate, gneiss, &c. It is embedded either in the earth that covers the limestone or in the rock itself, and exists in masses from the size of a pea to that of several tons' weight, generally angular, sometimes rounded, and, when in the latter form, 

they do not appear to have become so by attrition. * * * The emery has been 

formed and consolidated in the limestone in which it is found and-has not been detached from older rocks, as granite, gneiss, &c., and lodged in the limestone at the 

time of its formation. My reasons for so thinking are the following:

(1) In no instance could the closest investigation of the older rocks of these localities that are below the limestone furnish the slightest indication of the existence of 

emery there; and, moreover, the masses of emery in the limestone never had fragments 

of another rock attached to them. A few thin layers of mica slate were found in the 

limestone, but they were not in contact with the emery, nor contained any traces of 

corundum.

(2) The limestone immediately in contact with the emery differs almost invariably 

in color and composition from the mass of the rock; and at Kulat, where the marble 

forming the rock is remarkably pure, the part in contact with the emery is of a dark 

yellow color resembling spathic iron, and contains a large portion of alumina and 

oxide of iron. The thickness of this interposing coat between the emery and the 

marble is variable; but, what is certain, it passes gradually into white marble, so 

that their crystalline structures run into each other, showing that they are one and 

the same rock. * * * What we see is just what should be expected in ferruginous and aluminous minerals forming and separating themselves from a limestone not 

yet consolidated.

Other reasons are given to prove this point, and he gives a most instructive example of a nodule of emery surrounded by two concentric 

layers, the inner of chloritoid, a hydrous silicate of alumina and iron,

. M. L. Smith, Am. Jour. Sci. (II), XLII, pp. 83-93, 1866.

8 Am. Jour. Sci. (II), X, pp. 354^-370, 1850; XI, pp. 53-66, 1851.

(60).
CHATARD.J GNEISS DUNYTE CONTACTS OF CORUNDUM HILL. 61

the outer of margarite, a hydrous silicate of alumina and lime. Finally

he says:

At some future time * * * it will doubtless be found that emery forms the geognostic mark of extensive calcareous formations in that part of the world, just as the 

flints do in the chalk of Europe.

CONCLUSION.

From the foregoing examples it would seem that we have three types 

of corundum occurrences:

(1) In chlorites and allied minerals, the result of contact alterations 

between aluminous-alkaline silicate rocks and magnesian silicate rocks.

(2) In soda-lime feldspars, mainly depending upon the same reactions as No. 1, but complicated by the action of lime.

(3) In crystallized limestone, represented by the emery occurrences 

and that at Yernon, Sussex County, N. J., described by W. P. Blake.1

As to the character of the reactions producing this last class of occurrences, I am not at present able to say anything, and it will require a 

careful study of the relative influence of magnesia and lime, in this 

connection, before a?ny hypothesis can be stated.2

In considering the second type the facts that the feldspar is always a 

soda-lime feldspar, that it is found in connection with occurrences of the 

first type, and that margarite and other lime minerals are found in association point to a modification of type No. 1 through the action of lime. 

If the "hornblende gneiss" of the Buck Creek or Cullakenee Mine 

proves to be diorite, as has been stated, then we may be able to form a 

simpler idea of the course of the reactions.

The mode of origin of the duny te is readily seen to be foreign to that 

of the corundum, since the chemical reactions involved in the production of the latter are practically the same under each theory. If a 

chemical origin be assigned to the dunyte, then the corundum and chlo- 

. rite would be formed posterior to the gneiss and anterior to the dunyte, 

or even vice versa. If either the mechanical sedimentary or the igneous 

theory be assumed, then the corundum is posterior to both gneiss and 

dunyte and contemporary with the chlorite (and vermiculite), the two 

being equally alteration products. On the whole, it would seem that an 

igneous origin for the dunyte offers the simplest explanations.

That the chlorite and the corundum are contemporaneous is made 

evident by the intimate manner in which the two have crystallized 

together. In general the plates of chlorite would, seem to have attained 

considerable size before the corundum began to deposit and fill up the 

interstices, so that we have compact masses ranging all the way from 

almost pure corundum to almost pure chlorite. The u block corundum " 

of Laurel Creek is an example of the first class, while the u sand vein

'Am.- Jour. Sci. (II), XIII, p. 116, 1852; £. U. Shepard, Am. Jour, Sci. (Ill), IV, 

p. 179. 

2 J. L. Smith, Am. Jour. Sci. (Ill), VI, p. 182.

(61)
62 WASHINGTON LABOKATOKY. [DULL.42.

chlorite" of the same place shows the latter form. While perfectly 

formed crystals of pure corundum are not uncommon, we frequently find 

crystals with regular faces, but apparently formed in a solution having 

large numbers of small plates of chlorite or vermiculite floating in it, so 

that the corundum crystals carry many of the folia inclosed in them. 

If such a crystal, carrying vermiculite, is boiled in acid, the vermiculite 

is decomposed and more or less of the crystal disintegrates into corun. 

dum sand. Such crystals are found at Corundum Hill and specimens 

exist in the collection of the National Museum.

Whether or not the vermiculites are to be considered as resulting 

from the alteration of chlorites is a disputed point. Specimens are frequently found which show an apparent change from chlorite into vermiculite, the dark green folia of the one passing into the yellow brown 

of the other,1 but in most cases it is difficult to resist the conclusion that 

the chlorite now found with the vermiculite is not the residue of a process which has converted the rest into vermiculite. Such specimens from 

Corundum Hill show the chlorite apparently perfectly fresh and the 

form of the mineral entirely distinct from that of the associated vermic 

ulitej being usually much more broadly foliated. Moreover, we find 

seams containing'but little chlorite, the corundum being surrounded by 

vermiculite, while, but a short distance away and under apparently like 

conditions of exposure and weathering, veins are found filled with chlorite almost free from vermiculite. In this connection the observations 

of Cooke 2 are very interesting, and from what we know at present the 

derivation of one from the other is very doubtful. As to the relation of 

the chlorites (including vermiculites) to corundum, it is possible that 

this mineral may, in the process of alteration, occasionally furnish them; 

still, so far as field experience teaches, these minerals are the original 

gangue of the corundum and are not derived from it. The valuable researches of Dr. Gentli have shown that this mineral does alter, and, in 

so doing, produces many different mineral species; but whether any 

given mineral occurring with corundum is a result of the alteration of 

the latter must be determined for each case by the examination not 

only of the specimen but of its field surroundings also. Even when we 

have before us an apparently decided pseudomorph of some mineral 

after corundum it may prove to be only a case of envelopment, and 

this is particularly likely to be the case where the mineral in question 

is .found free from corundum in the same vein or even the same locality. Both damourite and margarite are found enveloping corundum, 

the outlines of the mass closely imitating the form of the inclosed crystal, so as to be easily mistaken for a true pseudomorph, and yet both 

of these minerals occur with corundum in such a manner that it is hardly 

possible to conceive that they are derived from it. The same may be

1 Grenth, op. cit., 1873, section " Jefferisite."

? Cooke, Proc. Am. Acad., Vol. IX, pp. 49-50, 1874.

(62)
OBATABD.J GNEISS DUNYTE CONTACTS OF CORUNDUM HILL. 63

said of the lime-soda feldspars, which, in general, present all the appearance of a gangue and not of an alteration product.

In concluding this paper it may be said that the information on this 

subject which has been gathered by different observers, while in the 

aggregate of considerable extent, is so far neither sufficient nor of a 

character to enable any one to speak with any great degree of confidence as to the mode of origin of this interesting mineral. Much more 

work, both in the field and in the laboratory is necessary; and, as a 

thorough investigation in this direction cannot fail to elucidate many 

points of great value to chemical geology, it is to be hoped that such 

work will be done. The value of corundum from the practical standpoint, the ease with which it can be recognized when occurring with 

other minerals, the great scientific importance of alumina, not only in 

its pure and crystallized condition, but also as a principal constituent of

the earth crust, aud therefore playing a part in almost all geoguostic

reactions, its varied and sometimes inexplicable chemical behavior, 

all tend to promise a rich return to the well equipped investigator.

(63)
A METHOD FOR THE SEPARATION AND ESTIMATION OF BORIC 

ACID, WITH AN ACCOUNT OF A CONVENIENT FORM OF APPARATUS FOR QUANTITATIVE DISTILLATIONS.

BY F. A. GOOCH.

In all successful methods for the estimation of boric acid, its comparative isolation is a necessary preliminary. Fortunately, the removal of 

nearly everything which interferes seriously with the proper execution 

of methods is not particularly arduous, but, of ordinarily occurring 

substances, two, silica and alumina both very commonly associated 

with boric acid are especially annoying in this regard. In the separation of alumina the trouble lies in the tendency of the precipitated 

hydrate to carry and retain boric acid,1 so that the two cannot be 

parted by means of ammonia or ammonia salts; with silica, the difficulty is in removing it completely. The volatility of boric acid stands, 

of course, absolutely in the way of treating with acid and evaporating 

to dryness, and every chemist knows the vainness of attempting to 

precipitate silica by means of ammonia, ammonia salts, or zinc oxide 

in ammonia. In Stromeyer's method2 the presence of silica is peculiarly harmful, since in passing to the condition of potassium fluosilicate this substance nearly quadruples its weight, and to free the 

potassium fluoborate from contaminating fluosilicate requires, according to Fresenius,3 at least six treatments by solution in boiling water, 

the addition of ammonia, and evaporation to dryness. Wb'hler 4 recommends evaporating the hydrochloric acid solution to dryness in a flask 

fitted to a condenser, collecting the distillate, reuniting the latter with 

the residue, and filtering from silica; and the operation is successful so 

far as the complete removal of silica is concerned, but the alumina, if 

present, is still in condition to give annoyance, and the other bases are 

yet to be separated. ' - Advantage has long been taken of the volatility of free boric acid 

with hydrofluoric acid or with alcohol to secure its removal from fixed 

substances, but so far as I know no attempt has been made heretofore 

to secure its complete volatilization and estimation in the distillate. The 

experiments which I proceed to describe are the result of an effort to 

accomplish this end.

! Wohler, Aun.'Chem. uurl Pharm., CXLI, p. 268. 

'Ann. Chem. und Pharm., C, p. 82.

3 Quailt. Chem. Anal., p. .424.

4 Handbook of Mineral Analysis, under Datholite.

64 (64)
GOOCH.] METHOD FOR THE SEPAEATION OF BORIC ACID. 65

Aside from the difficulties in manipulation and in the construction of 

apparatus which the use of hydrofluoric acid would involve, this reagent is otherwise plainly inapplicable to the purpose in view, and of 

other agents with which boric acid is known to volatilize freely methyl 

alcohol seems to present the most desirable qualities. Methyl alcohol, 

ethyl alcohol, and water are effective in the order in which they are 

named. Thus to volatilize 1 grin, of boric acid the equivalent, speaking roughly, of about 0.5 grm. of boric anhydride two treatments with 

10 cm.3 of methyl alcohol and evaporation to dry ness in each case were 

adequate; for the volatilization of 0.2 grm. of boric acid were required 

two treatments of 10 cm.3 each of ethyl alcohol, succeeding an evapora-' 

tiou with 50 cm.3 of the same alcohol; and the residue of five evaporations of water over 0.4 grm. of boric acid, taking in each case 50 cm.3 

of water, followed by ignition, weighed 0.08 grm., or one-fifth of the 

original weight. In the presence of water, methyl alcohol is not equally 

effective; arnyl alcohol and sulphuric acid restrain its action similarly, 

doubtless by dilation simply, caud hydrochloric acid seems to possess 

no advantage over water alone in developing the volatility of boric 

acid. As an example an experiment may serve in which a solution of 

0.4 grm. of boric acid in 50 cm. 3 of water, after being heated three times 

successively with 25 cm.3 of methyl alcohol until the boiling point rose 

in every case nearly to that of water, and then evaporated to dryness, 

left a large residue which disappeared with a single charge of 25 cm.3 

of methyl alcohol applied by itself.

From the residue of the evaporation of borax with hydrochloric, 

nitric, or acetic acid, methyl alcohol, as would naturally be predicted, 

volatilizes the boric acid freely, though the presence of foreign material acts to a certain degree protectively and tends to diminish the 

rapidity with which the alcohol would otherwise effect extraction and 

volatilization. In case, however, that acetic acid is used to break up 

the borate, the tendency of sodic acetate to lose acid and become alkaline simply by exposure to evaporation in its aqueous solution makes 

it necessary to insure the acidity of the residue of evaporation by adding a drop or two of acetic acid before repeating the treatment with 

methyl alcohol.

On the whole, methyl alcohol shows itself to be an excellent agent by 

which to secure the volatilization of boric acid.

To retain free boric acid, magnesium oxide naturally suggests itself. 

According to Marignac 1 it is effective, and, if in the course of analysis 

it may have been partly converted to the chloride, it is easily regenerated by the action of heat and moisture. Marignac, it will be remembered, makes use of magnesia mixture the chlorides of ammonium and 

magnesium with free ammonia to fix the boric acid, evaporating the solution to dryness, igniting, extracting with boiling water, filtering, and 

weighing the residue, while the filtrate is again treated as before to re1 Zeitschr. anal. Chem., I, p. 406. 

Bull. 42 5 (65)
66 WASHINGTON LABORATORY. [BULL. 42.

cover traces of the-borate which has yielded to the solvent action of 

the water. During the drying and ignition the magnesium chloride 

yields hydrochloric acid, and it would seem scarcely possible that the 

magnesium borate should fail to show some loss of boric acid when both 

hydrochloric acid and moisture exert their action. Further, the presence 

of ammonia during evaporation does not prevent the volatilization of 

boric acid, 1 and Marignac regards the addition of it from time to time 

as of doubtful use. So it appears natural to look for some loss under 

such conditions, and Marignac fully recognizes the fact that the apparent accuracy of his method is due to the balancing of errors, the inclusion of foreign matter by the magnesium borate and the deficiency of 

the magnesia when precipitated as ammonio-magnesium phosphate together compensating for the loss of boric acid by volatilization. To 

bring the matter to the test, the following experiments were made. In 

them and in all succeeding experiments the boric acid was weighed in 

solution, the standard of this having been fixed by dissolving in a 

known weight of water a known weight of fused boric anhydride prepared in a state of purity by frequent recrystallization. The magnesium 

oxide employed was made from the pure chloride by precipitating by 

ammonium carbonate and igniting, and was free from lime and alkalies 

and so far as could be determined was otherwise pure. The whole operation of each experiment was conducted in one vessel, so as to avoid transfers. In all cases a weighed platinum crucible of 100 cm.3 capacity received 

a weighed portion of magnesia, and after ignition and subsequent weighing the weighed solution of boric acid was introduced. In experiments 

(1) to (4) the magnesia was thoroughly stirred in the solution of boric acid, 

the evaporation carried at once to dryness, and the crucible and residue 

ignited and weighed;, in experiments (5) to (8), the magnesia was dissolved, after the addition of the boric acid, in hydrochloric acid sufficient in amount to prevent the precipitation of magnesium hydrate on 

the subsequent addition of ammonia, ammonia introduced in considerable excess in (7) and (8), in distinct excess in (5) and (6), the whole 

evaporated and ignited, the residue moistened and again ignited, and 

this last treatment repeated until the residue ceased to yield vapor of 

hydrochloric acid when heated.

MgO

((1)

) (2)

) (3)

((4)

("(5)

) (<>)

) (?)

((8)

taken.

grm. 

0. 1734

0. 1804

0. 1793

0. 1794

0. 1807

0. 1789

0. 1806

0. 1789

taken.

grm. 

0. 5005

0. 4973

0. 4949

0. 4941

0. 4984

0. 4974

0. 4944

0. 4959

found.

grin. 

0. 6607

0. 6660

0. 6640

0. 6627

0. 6542

0. 6687

0. 6684

0. 6672

found.

grm. 

.0. 1602

0. 1687

0. 1691

0. 1686

0. 1558

0. 1560

0. 1740

0. 1713

grm. 

0.0132-

0.0117-

0. 0102 -

0. 0108 -

0.0249-

0. 0229 -

0. 0066 -

0. 0076 -

1 Rose, Pogg. Aun. } LXXX, p. 262. 

(66)
GOOCH.I METHOD FOR THE SEPARATION OF BORIC AQID. 67

From these results it appears plain that under the conditions of the 

experiments neither magnesia alone nor the magnesia mixture is efficient 

in fixing boric acid ; bufc in experiments (7) and (8), in which ammonia 

was employed in large excess, the loss of boric acid is least; so that it 

would seem to be the case that though ammonia is not a perfect preventive of volatilization it does exert a restraining action on the boric 

acid. That the magnesia mixture should be incapable of retaining entirely the boric acid present is. as has been pointed out, not surprising; 

but that the loss should be so great is rather startling, and more than 

suggests that the errors of Marignac's process are seriously excessive. 

The failure of magnesium oxide to hold back boric acid under the conditions of the experiment must be due to a cause other than that which 

determines the loss during the evaporation and ignition of the magnesia 

mixture, and for this ifc is natural to turn to the insolubility of the 

oxide, a quality likely to oppose some difficulty in the way of establishing complete contact between the boric acid .and the magnesia dur- 

. ing a short exposure. Direct tests of this point showed distinctly that 

mixtures of boric acid in water and magnesia, when submitted at once 

to distillation, yielded boric acid to the distillate; but that, if the mixtures were permitted to stand some hours before distilling,' the oxide 

passed to the sernigelatinous condition of the hydrate and retained 

the boric acid so firmly that turmeric failed to show the presence of the 

latter in the distillate. It is plain, therefore, that with sufficient preliminary exposure magnesia might be relied upon to retain boric acid; but 

inasmuch as long and perhaps somewhat indefinite periods of waiting 

are objectionable in any analytical process, it was thought best to try 

the effect of substituting lime for magnesia. Experiments (9) to (12), 

conducted like the previous ones, excepting only the use of carefully 

prepared and ignited calcium oxide instead of magnesium oxide, were 

made with this end in view.

B2 03 CaO CaO+BjOs B2 0., Error, 

taken. takeii. found. foimd.

grm. grm. grin. K rm - grni -

(9) 0.1810 0.9737 i. 15GO 0.1823 0.0013+

(10) 0.1819 0.9750 1.1583 0.1833 0.0014+

(11) 0.1808 0.9922 1.1810 0.1818 0.0010+

' (12) 0.1833. 0.9715 1.1560 0.1845 0.0012+

These figures indicate sufficiently that there is no loss of boric acid 

by volatilization when its aqueous solution is evaporated in contact 

with calcium hydrate; but, inasmuch as the comparative solubility of 

the latter is the quality which makes it effective where magnesia is not, 

it seemed desirable to test the action of calcium hydrate in alcoholic 

solutions, in which it is very insoluble. The experiment showed that 

Avhen the solution of boric acid in methyl or ethyl alcohol is put upon 

lime and distilled at once loss is apt to take place, and sometimes to a 

very considerable amount, but that a short period of digestion, with

(67)
68 WASHINGTON LABORATORY. [BULL. 42.

^^

FIG. 3. Apparatus for determination of boric acid

(68)
GOOCH.] METHOD FOR THE SEPARATION OF BORIC ACID. 69

The apparatus which is shown in the accompanying cut consists 

essentially of a retort, a condenser, and a bath lor heating. For the 

last I have used a paraffine bath, as being, on the whole, the most convenient. The condenser is set vertically, to facilitate changing the level 

of the retort within the bath and to secure at the same time continual and thorough washing of the tube by its own condensations. 

The retort, somewhat like the well known drying tube of Liebig in general shape, is easily made of a pipette by bending the tube at one end to 

a right angle, at the other to a gooseneck, as shown. To the former 

end is fitted, by a rubber stopper or section of tubing, a glass funnel 

tube provided with a stop cock; the end of the goose neck passes tightly 

through a rubber stopper in the upper end of the condensing tube. 

This is essentially the apparatus, but it is convenient to attach, to receive 

the distillate, a small Erlenmeyer flask, which moves with the condenser 

and is joined to it, in the manner indicated in the figure, by means of a 

thistle tube and a rubber stopper grooved to permit the free passage of 

air. In carrying out a distillation, the liquid to be distilled is introduced into the retort either by the funnel tube or previous to its insertion, the glass cock is closed, the water started through the condenser, 

and the retort lowered into the hot paraffine, care being taken to begin 

the operation with the retort not more than half full and so inclined 

that only the rear dips below the surface of the bath. If the precaution to heat the retort at the start in this manner be overlooked, it may 

sometimes happen that the sudden and violent expulsion of air through 

the liquid will carry portions of it bodily into the gooseneck, and even 

into the condenser. With this point considered, the remainder of the 

operation presents no difficulty and requires little care.

The size of the retort may be suited, of course, to the particular case 

in hand, but for most purposes a 200 cm.3 pipette makes a retort of 

convenient dimensions, neither too large for the distillation of small 

charges nor too small to permit the treatment of 100 cm. 3 of liquid comfortably. The tube of the goose neck should be wide enough to prevent the formation of bubbles in it; 0.7 cm. is a good measure for the 

interior diameter. It is of advantage to heat the bath to a point considerably above the temperature at which the liquid which is to be distilled boils something between 130° 0. and 140° C. does very well for 

water and is not too high for methyl alcohol and under such circumstances, and when the retort is entirely submerged, it often happens 

that evaporation takes place with extreme rapidity from the surface of 

the liquid in perfect quiet without actual boiling.

With such an apparatus the following experiments were made. The 

boric acid was weighed, as before, in solution, and, to bring the condition of the experiment to that of an actual analysis, 1 grm. of pure 

sodium hydrate was added in solution, nitric acid or acetic acid to 

acidity and a little more, and the whole was' introduced into the retort 

and distilled to dryness.

(69)
70 WASHINGTON LABORATORY. IBULL. 42.

In those experiments in which, nitric acid was employed, the methyl 

alcohol was introduced upon the residue thus dried in six successive 

portions of 10 cm.3 each and distilled to dryuess; but in order to break 

up the residue of sodium nitrate, which by its insolubility might affect 

to some extent the protection of the boric acid from the action of the 

alcohol, 2 cm.3 of water were introduced and evaporated between the 

second and third and again between the fourth and fifth distillations.

When acetic acid was made use of to free the boric acid, the six distillations with methyl alcohol were made as before; but, sodium acetate 

being soluble in methyl alcohol, the intermediate treatments with water 

were unnecessary. With the fourth portion of methyl alcohol a few 

drops of acetic acid were added to preserve the acidity of the residue, 

which, as has been pointed out, tends to become alkaline under the 

treatment.

The residues of both processes of treatment were found to be free 

from boric acid by the exceedingly delicate test with turmeric, care being taken in the series of experiments in which nitric acid was used to 

oxidize nitrites by means of bromine (expelling the latter before making 

the test), and in the acetic acid series to acidify with hydrochloric acid 

sufficiently to counteract the tendency of the acetate by itself to brown 

the turmeric on evaporation.

The lime to retain the boric acid in the distillate was ignited in the 

crucible in which the evaporation of the distillate was to be made subsequently, and then transferred to the receiving flask attached to the 

condenser, so that the boric acid might be fixed during the distillation. 

To prevent the caking of the lime by the action of the alcohol, it was 

slaked with a little water before the distillation was begun.

In experiments (13) to (16) nitric acid was employed and in (17) to 

(20) acetic acid was used, with the precaution noted, to liberate the 

boric acid. *

"(13)

(14)

(15)

.(16)

'(17)

(18)

B?0s '

taken.

grm. 

0. 1738'

0. 1806

0.1779

0. 1824

0. 1806

0. 1812

. CaO

taken.

grm. 

0. 9647

0. 9639

0.9665

0. 9739

' 1. 4559

0. 9720

BsOs+CaO 

found.

grm. 

1. 1392

1. 1456

1. 1450

1. 1587

1. 6371

1. 1543

B20s 

found.

grm. 

0. 1745

0. 1817

0. 1785

0. 1848

0. 1812

0. 1823

Error.

grm. 

1 0. 0007+

0.0011+

0. 0006+

0. 0024+

0. 0006+

0. 0011+

>

(19) 0.1788 0.9986 1.1781 0.1795 0.0007+ 

(20) 0.1813 0.9527 1.1358 0.1331 0.0018+ '

In experiments (13) to (16) the mean error amounts to 0.0012+ grm.; 

in experiments (17) to (20) the mean error is a little more than 0.0010+ 

grm. Throughout the entire series of experiments the tendency to yield 

figures slightly larger than the truth is manifest, but the error is quite

(70)
OOOCH.] METHOD FOR THE SEPARATION. OF BORIC ACID. 71

within legitimate limits. The greatest care was taken to secure similarity of conditions under which the crucible and the lime were weighed 

before and after the evaporation and absorption of boric acid, and the 

weight after ignition was taken in every case after cooling over sulphuric 

acid during a definite period often minutes, in order to eliminate as far 

as possible the effect of atmospheric condensation upon the large surface of platinum. Ignitions were always finished over the blast lamp, 

and constancy of weights was secured.

The results indicate that both modes of treatment are on the whole 

equally satisfactory.

In the presence of chlorides, it is of course impossible to employ 

nitric acid to free the boric acid. Oxalic, citric, and tartaric acids also 

liberate hydrochloric acid to a considerable extent from alkaline chlorides. It was found, however, that when acetic acid was distilled over 

sodium and potassium chlorides only traces of hydrochloric acid passed 

into the distillate, and experiments (21) to (23) were made to determine 

whether these amounts are sufficient to vitiate the separation of boric 

acid from alkaline chlorides by distillation in presence of free acetic 

acid. The details of treatment were identical with those of experiments 

(17) to (20), excepting only the addition of 0.5 grm. of sodium chloride 

to each portion before distillation.

BsOs CaO BaOs+CaO B203 

taken. . taken. found. ' found.

.grm. 

' (21) 0. 1834 

(22) 0. 1831

(23) 0. 1761

grm. 

0. 9842

0. 9755

0. 9740

grm. 

1. 1675

1. 1593

1. 1523

grm. 

0. 1833

0. 1838

0. 1783

grm. 

0.0001-

0. 0007+

0. 0022+

The mean error of these results is about 0.0009+ grm., and it is plain 

that the presence of sodium chloride does not materially change the conditions of the experiment. There seems, therefore, to be no reason why 

boric acid may not be separated by distillation from alkaline chlorides 

in presence of free acetic acid; but it was found that the presence of 

any considerable amount of potassium acetate is disadvantageous. 

Sodium acetate to a reasonable amount does not interfere with the favorable progress of the separation ; but potassium acetate appears to require a much higher temperature for the expulsion of its water, and 

longer distillation.

When, therefore, chlorides are present in the salts from which boric 

acid is to be removed by distillation, the choice is open between two 

methods. The distillation may be made directly with an excess of acetic 

acid ; or the hydrochloric acid may be first removed by means of silver 

nitrate and the distillation of the filtrate proceeded with at once or 

after precipitation of the excess of silver salt by means of sodium hydrate or carbonate, care being taken to acidify again sufficiently with 

nitric acid after the removal of the silver. Of these two modes of proceed-

(71)
72 WASHINGTON LABOKATOKY. [BULL.42.

ing, I incline to the treatment with nitric acid and the removal of the 

chlorine by precipitation ; and this method has been used with success 

by others as well as myself for some mouths in the analysis of waters 

carrying boric acid and natural borates.

The process in either modification is fairly accurate and easily executed and admits of very wide application. Insoluble compounds in 

which the boric acid is to be determined may be dissolved in nitric acid 

at once, or, if necessary, first fused with sodium carbonate j and, fortunately, nearly everything which is volatile in the subsequent treatment 

and capable of forming with lime compounds not easily decomposable 

by heat may be removed by known processes. The combination of 

fluorine, silica, and boric acid is perhaps most difficult to treat; but the 

precipitation and removal of the first as calcium fluoride from the aqueous solution of a fusion in alkaline carbonate may, it is believed, be effected with care, and the mode of procedure from that point is simple.

The number of distillations necessary depends, of course, upon the 

amount of boric acid treated. To remove 0.2 grm. of boric anhydride 

completely to the distillate, six charges of methyl alcohol, of 10 cm.3 

each, proved, as we have seen, to be ample.

The apparatus by the aid of which the distillation processes which 

have been described were carried out has found useful application in a 

number of other processes. In the determination of free and albuminoid 

ammonia in waters which can be boiled quietly with difficulty, in the 

methods of estimating hydrofluoric acid which involve the expulsion of 

silicon fluoride from a mixture of the fluoride with sulphuric acid and 

silica, in the separation of iodine from bromides and chlorides by distilling with ferric sulphate and sulphuric acid and of bromine from 

chlorides by means of permanganic acid, it has proved of value, and it 

will doubtless be found convenient in many analytical processes in which 

quantitative separations by the distillation of liquids liable to spatter 

or boil explosively are involved.

(72)
A METHOD FOR THE SEPARATION OF SODIUM AND POTASSIUM 

FROM LITHIUM BY THE ACTION OF AMYL ALCOHOL ON THE 

CHLORIDES, WITH SOME REFERENCE TO A SIMILAR SEPARATION OF THE SAME FROM MAGNESIUM AND CALCIUM.

BY F. A. GOOCH.

For the quantitative separation of lithium from sodium and potassium Mayer's method,1 which is based upon the precipitation of lithium 

as the tribasic phosphate, and Eainmelsberg's2 mode of parting the 

chlorides by means of a mixture of anhydrous alcohol and ether in 

equal parts have been available.

The method of Mayer grew out of the older process of Berzelius,3 

which consisted essentially in treating the solution of the alkaline salts 

with phosphoric acid and sodium carbonate in excess, evaporating to 

dryness, and extracting with cold water. The result of a single analysis of the product thus obtained was the testimony upon which Berzelius rested the belief and statement that the salt was a double phosphate of lithium and sodium, which left upon ignition sodium and 

lithium pyrophosphates in equal molecules ; and on this Berzelius based 

his process for the estimation of lithium. Eammelsberg,4 however, 

showed later that it was a tribasic phosphate which was actually obtained, and from his experiments arrived at the conclusion that the 

proportions of soda and lithia were variable within wide limits, the 

amounts of the former varying in the special cases investigated from 

7.84 per cent, to 28.38 per cent. ; and the same thing in substance was 

reiterated subsequently5 in an account of a repetition of the work suggested by the criticism of Mayer. Mayer,6 however, was unable to prepare under any conditions the double phosphate of Eammelsberg, and 

obtained invariably, when the preparation had been washed with sufficient care, trilithium phosphate free from sodium; but the point was 

made that the phosphate is apt to be contaminated with lithium carbonate when sodium carbpnate is employed to bring about alkalinity.

. 193. 4 Loc. cit.

2 Pogg. Ann., LXVJ, 79. 8 Pogg. Anu., CII, 443.

3 Id., IV, 345. G Loc.cit.

(73) 73
74 WASHINGTON LABORATORY. [BUM. 42.

Mayer therefore modifies the method of Berzelins by substituting 

sodium hydrate for the carbonate, and, proceeding, evaporates to dryness, treats the dry mass with as much water as is needed to dissolve 

the soluble salts with the aid of heat, adds a drop or two of sodium 

hydrate if necessary to restore alkalinity, and then ammonia in volume 

equal to that of the water already added, sets aside at a gentle heat, 

filters only after twelve hours, and washes with a mixture of ammonia 

and water in equal parts. From the filtrate and first washings a small 

amount of the lithium phosphate is to be recovered by evaporation and 

the repetition of the former treatment. According to Mayer the precipitation of the ^phosphate may be effected with equal completeness 

by boiling the solution, prepared as before, instead of evaporating it; 

but the objection to' this mode of proceeding is the tendency of the 

liquid carrying the precipitate to bump explosively. Careful washing, 

somewhat prolonged, is essential to secure the complete removal of 

salts of sodium and potassium, and it is remarked that the purity of 

the precipitate is shown by its failure to cake when strongly ignited.

This is the mode of proceeding by which Mayer separates lithium 

from sodium and potassium, isolating it as presumably pure trilithium 

phosphate and weighing it as the anhydrous salt. In dealing with 

mixtures of the chlorides in which the proportion of the lithium salt is 

relatively small, the removal of the greater part of sodium and potassium chlorides by a preliminary treatment with absolute alcohol is 

recommended. The following table comprises the results of Mayer's test 

analyses of lithium carbonate in the first seven, of lithium sulphate in 

the last two, recalculated with the use of the number 7 the figure now 

generally accepted as the atomic weight of lithium.

	LisPO, found. Error. 

grin. grin. grin. 

1.3586 1.3719 0.0133+ 

1.5172 ' 1.5088 0.0084- 

0.7519 0.7580 0.0061+ 

0.9561 0.9510 0.0051- 

1.2651 1.2646 0.0005- 

1.2197 1.2230 0.0033+ 

0.8991 0.9018 0.0027+ 

1. 1325 1. 1236 0. 0089- 

0.9715 0.9665 0.0050-

Fresenius l found on examining the method that several repetitious 

of the treatment by evaporation and extraction were required to complete the recovery of all lithium phosphate, and advised that the operation be continued until residual lithium phosphate fails to appear. The 

results of Fresenius's experiments with lithium carbonate, recalculated

1 Zeitschr. anal. Cliem., I, p. 42. 

(74)
GOOCII.] SEPARATION OF SODIUM FEOM LITHIUM. 75

with the use of the number 7 as the atomic weight of lithium, are.given 

in the table appended.

LisPOa equivalent LisPOj fonnd. -^ 

to salt taken. Dried at 100° C. Ignited. -L.nor.

grin. grm. grm. gnu.

f after two treatments 0.7243 ...... 0.0200 

0.7443 ] " t]iree ". 0.7385 ...... 0.0058 

[ " four " 0.7433 ...... 0.0010-

( 0.9861 ......' 0.0041+

0>982° { ...... 0.9826 0,0006+

( 1.6342 ...... 0.0001+

f 1.6,341 j 1.6305 0.0036-

Thus it will be seen that in the nine experiments of Mayer the error 

ranges from 0.0133+ grm. to 0.0089 grm., and that of the determinations of Fresenius from 0.0001+grm. to 0.0041+gnn. for the dried precipitate and from 0.0006+ grm. to 0.0036 grm. for the ignited precipitate.

If the tendency of lithium carbonate to fall in company with the phosphate were not to assert itself during the evaporations of solutions of 

salts of lithium, in presence of sodium hydrate and in contact with ordinary atmospheric air, it would surely be strange, and this point may 

be fairly set down as one of the weak ones of the method j but the 

gravest source of error, and that indicated most unmistakably throughout the whole history of the process which has been recounted at some 

length for the purpose of emphasizing this very matter is the impossibility of preparing the lithium phosphate in anything like a condition 

of freedom from other alkaline phosphates without a careful and prolonged washing, which is sure to result in loss of the lithium salt by 

solution. When it is remembered that according to Mayer's determinations trilithium phosphate requires for solution only 2,539 parts of 

water or 3,920 parts of a mixture of ammonia and water in equal portions, it is plain that the success of the method depends upon the ability of the analyst to wash to a condition of purity, and without loss of 

that which it is the purpose of the process to save, a precipitate peculiarly prone to retain foreign matter and soluble in the washing mixture 

in the proportion of 10 milligrams to every 40 cm.3 of the latter. Of 

course washings will never be entirely saturated, nor will.the precipitate be as soluble at the beginning of the operation as at the end, when 

the precipitant no longer exerts an action which tends to lessen solubility ; but in view of the difficulties which present themselves, it is sufficiently obvious that exact results obtained by Mayer's process owe their 

apparent accuracy to a fortuitous balance of errors. The difference of 

0.0222f grm. between the extremes of Mayer's experimental results 

should not be surprising; and, at the best, the process is tedious and 

not entirely trustworthy, facts of which its author was not unmindful.

(75)
76 WASHINGTON LABORATORY. [BULL. 42.

In Eammelsberg's method of separating lithium chloride from the 

chlorides of sodium and potassium the sources of error are, in brief, 

the solubility of sodium chloride and potassium chloride in the etheralcohol mixture, the influence which the presence of small amounts of 

water exerts upon the solubility of these same salts, the difficulty of 

bringing the chlorides to the anhydrous condition without decomposing 

the lithium chloride to a greater or less extent, and the mechanical 

difficulties of transferring the fused or crusted chlorides to a suitable 

receptacle for digestion and agitation, in the solvent, and of extracting 

perfectly the soluble constituents of closely compacted matter. Of the 

last two items nothing need be said in explanation beyond simply 

noting them. The third is particularity important, inasmuch as the 

tendency of lithium chloride, first noted I believe by Mayer, to exchange chlorine for oxygen when ignited in presence of water, results 

in the formation of lithium hydrate or, in contact with products of 

combustion, lithium carbonate, both of which are insoluble in the 

mixture of ether and alcohol and remain with the sodium and potassium chlorides. As to the effect of water in the mixture, an experiment of Mayer, in which it was found that 100 cm.3 of a mixture of 

alcohol of 96 per cent, and ether of 98 per cent, dissolved 0.1100 grm. 

of sodium chloride, is instructive. In regard to the solubility of the 

chlorides of sodium and potassium in the mixture of anhydrous ether 

and alcohol, Kammelsberg's statement that from 0.9770 grm. of pure, 

strongly heated sodium chloride with an undetermined amount of 

lithium chloride the mixture extracted 0.0130 grm. is unfortunately 

meaningless in the absence of information concerning the amount of 

solvent employed. J. Lawrence Smith1 found, in making an examination of this matter, that 10 cm.3 of the anhydrous ether-alcohol mixture extracted from 0.5 grm. of sodium chloride 0.0005 grm. and from 

0.5 grm. of potassium chloride 0.0003 grm. Smith's mode of applying

the method is better than the original; for, by taking care iiot to heat 

the mixed salts above 100° 0., the danger of decomposing the lithium 

chloride is diminished, and by treating the dried salts with the etheralcohol mixture in the capsule in which it is heated and weighed (protecting it by a small inverted bell glass) the disadvantage of the transfer is avoided, but the danger is incurred that the mixed salts may not 

be thoroughly dried by heat so gentle. With this modification Smith 

obtained results which are rearranged in the following statement, and 

which do not throw a very favorable light upon the method :2

'Am. Jour. Sci. (2), XVI, p. 56.

2 Dr. Smith's language in the description of these experiments is somewhat ambiguous, but it is believed that these figures represent the meaning intended. After 

the presentation of the data of the first experiment given here with the correction of 

an obvious typographical error, it is said of the second and third experiments that 

" a similar.mixture containing 18.10 per cent, of chloride t>f lithium furnished a residue of 17.65 per cent." and " a similar mixture containing 67.20 per cent, of chloride

(76)
OOOCH.] SEPARATION OF SODIUM FROM LITHIUM. 77

NaCI taken. KC1 taken. LiCl taken. "Weight dissolved. Error.

grm. grin. grm. grm. grin. *

0.2000 0.2000 0.0080 0.0101 0.0021+

0.2000 0.2000 0.0884 0.0862 0.0022-

0.2000 0.2000 0.8195 0.8341 0.0146+

It is obvious, therefore, that neither the method of Rammelsberg nor 

that of Mayer may justly claim to be what a good process should be, 

accurate and rapid; and in the dilemma many chemists have been inclined to accept, with Bunsen, 1 the inherent disadvantage of an indirect process, and in a mixture of sodium and lithium chlorides calculate 

the percentage of each from the known weight of the mixture and its 

contents in chlorine, and in a mixture of the three chlorides calculate 

the percentage of each from the known weight of the mixture and the 

determined contents in chlorine and potassium. Here again, however, 

as in Eammelsberg's process, the difficulty of bringing the chlorides to 

a definite condition for weighing without decomposing the lithium 

chloride is an obstacle; and in case potassium is to be separated from 

large amounts of lithium by precipitation as potassio-platinic chloride, 

the concurrent precipitation of a similar salt of lithium, to which Jenzsch2 

has directed attention, may be the occasion of inexactness. So, the 

intrinsic unsatisfactoriness of indirect methods quite aside, it appears 

that in following Buusen we have by no means all that is to be desired 

in an analytical method.

In looking about for better means for the separation of lithium from 

sodium and potassium, certain preliminary experiments on the behavior 

of the chlorides of these elements toward arnyl alcohol gave very encouraging indications, and subsequent quantitative tests have borne 

out the hope that a successful method of separation Nmight be based 

upon these relations.

In arnyl alcohol the chlorides of sodium and potassium are highly 

insoluble, lithium chloride dissolves freely, and the attraction of amyl 

alcohol for water is so slight and its boiling point so far above 100° C. 

that the latter may be expelled without difficulty by the aid of gentle 

heating.

When amyl alcohol is poured into a solution of lithium chloride in 

water the liquid forms two layers, the aqueous solution of the salts at 

the bottom and the amyl alcohol now carrying a little water above. 

With the application of heat, the water evaporates slowly, then boils, 

and, passing through the alcohol, escapes, until toward the end of the 

operation the residual lithium chloride collects in a viscous globule and

of lithium gave a residue of 68.40." I have taken this to moan that iu all three experiments 0.2 grm. of sodium chloride aud 0.2 grm. of potassium chloride were employed with the different proportions of lithium chloride indicated for each experiment. At all events, if this is not the meaning of the language made use of, it is 

difficult to see a definite value in the experiments.

1 Ann. Chem. und Pharm., CXXII, p. 348.

»Pogg. Ami., CIV, p. 102.

(77)
78 WASHINGTON LABORATORY. [BULL. 42.

finally dissolves, with the exception of a slight incrustation. If now the 

alcohol is cooled and a drop of strong hydrochloric acid is added and 

brought in contact with the deposit and the boiling repeated, the solution is complete. This deposit I take to be lithium hydrate, resulting 

from the decomposition of the chloride by the protracted action of water 

at a temperature near its boiling point. The small amount of water 

which is added in and with the hydrochloric acid seems to exert no 

unfavorable influence, but rather to be beneficial in hastening the solution of the residue by securing immediate and sufficient contact.

In hot amyl alcohol, lithium chloride appears to be a little more 

soluble than in the same reagent at ordinary temperatures, but the solubility under the latter condition only was determined. By boiling the 

solution until turbidity began to show, cooling, filtering, and then evaporating a known volume of the concentrated solution to dryness and 

Aveighing the residue after converting it to the sulphate, it was found 

that one part of lithium chloride was held dissolved in the cold in about 

fifteen parts of amyl alcohol, 10 cm.3 of the solution containing in the 

mean 0.66 grm. of the chloride.

When aqueous solutions of sodium chloride or potassium chloride are 

treated with amyl alcohol and boiled, the water disappears, as before, 

leaving first a globule of the concentrated solution and finally the crystalline salts. On continuing the boiling until a thermometer dipped in 

the liquid indicates the temperature, at which the alcohol boils by itself, 

a slight additional precipitation, doubtless due to the expulsion of the 

water retained by the alcohol up to this point, takes place upon the walls 

of the containing vessel. The results of quantitative tests of the solubility of sodium and potassium chlorides are given in the following 

tables. The strengths of the solutions of sodium chloride and potassium 

chloride were determined by evaporating weighed portions in a platinum crucible and drying at a temperature considerably below the melting point of the salt, and weighing. The solution of lithium chloride 

was standardized by treating a weighed portion with sulphuric acid in 

excess, evaporating, igniting at red heat, and weighing. The standards 

were fixed by experiments (1) to (9).

Weight of solution Weight of Weight of NaCl iu -^ 

of .NaCl taken. KaCl found. 10 grm. of solution. muui.

grm. grm. grm.

(1) 10.7110 . 0.1072 0.1001-J gm>

(2) 10.9419 0.1097 0.1003 £ 0.1002

(3) 10.9325 0.1097 0.1003J

Weight of solution Weight of: Weight of KaCl in Ar 

of KaCl taken. KaCl found. 10 gnn. of solution. Juean.

grm. grin. grm.

(4) 9.3045 0.1744 0.1874^/ grm.

(5) 10.7225 0.2000 0.1871 \ 0.1872

(6) 11.1974 0.2096 0.1872J

(78)
GoocH.1 SEPAEATION OF SODIUM FROM LITHIUM. 79

Weight of solution "Weight of Weight of LiCl in .

of LiCl taken. LijSOa found. 10 grm. of solution.

gnn. grin.

(7) 10.9280 0.1635 0.1156^

(8) 11.1480 0.1665 0.1153 C 071154

(9) 10.8790 0.1626 0.1154 J

3 ft 

3 I

To determine the solubility of sodium 'chloride and potassium chloride in amyl alcohol, portions of the test solutions were weighed out, 

evaporated to a convenient bulk in platinum crucibles of 100 cm.3 

capacity, amyl alcohol was added, the water expelled by boiling, and 

the heating continued for some minutes after the thermometer in the 

liquid indicated 132° 0., the boiling point of the alcohol employed. 

The liquid was then decanted with care and the residue dried at a temperature below its melting point and weighed. When the chlorides are 

precipitated in the manner described, the deposit generally adheres so 

closely and such particles as do remain loose settle so well that the 

supernatant liquid maybe decanted to the end without appreciable 

transportation of the insoluble residue. For the sake of perfect security, 

however, in this part of the manipulation the decanted liquid was 

filtered under gentle pressure upon asbestus, with the aid of the device 

which I have previously described for such purposes, 1 and, after gentle 

heating, the increase in weight of the felt and the containing perforated 

crucible was added to the weight of the residual salt. In no case did 

this increase exceed a few tenths of a milligram and often could not be 

detected.

As a source of heat, a bath in which the sand of the sand bath is replaced by smooth asbestus board is a convenience, or a piece of asbestus 

board simply, about 30 cm. square, supported by a broad tripod and 

heated under the middle by a Bunsen burner, answers equally well to 

secure every gradation of heat without danger of igniting the evaporated alcohol.

As a control upon the results obtained by weighing the residue as 

described, the filtrate was evaporated in a large platinum crucible and 

the residue thus left gently heated and weighed. Though the evaporation be conducted with extreme care, the residue is almost sure to 

show some blackening, due to the carbonization of matter carried by 

the alcohol, which will not disappear entirely without the 'application of 

a degree of heat which the salts cannot bear without danger of volatilisation. The weight of the residue from the amyl alcohol itself is small, 

one portion of 50 cm.3 yielding 0.0003 grm. and its mate 0.0007 grm., 

so that the data obtained by the evaporation of the filtered alcohol of 

the experiments, if not quite so trustworthy as the former testimony,

1 Proc. Am. Acad., Vol. XIII, p. 342.

(79)
80 WASHINGTON LABORATORY. [BULL. 42.

may nevertheless serve the purpose of a very close control. Both sets 

of data are given in the following table:

"Weight of 

Nad taken.

((10) 

1(11)

((12) 

1(13)

grm.

0.1062 

0.1043

0.1024 

0.1003

Total weight of 

NaCl found.

grm.

0.1067 

0.1047

0.1030 

0.1008

"Weight found 

in residue.

grm.

0.1043 

0.1024

0.1003 

0.0983

Weight found 

in solution.

grin.

0.0024 

0.0023

0.0027 

0.0025

Volume of residual amyl 

alcohol.

cm. 3

52 

46

. 51 

45

Eeducing these figures to a common level to .show the action of the 

same amount of amyl alcohol in every case we have:

LossofNaClto 

100 cm. 3 of 

amyl alcohol.

grm.

i (10) 0.0037 -\ 

\ (11) 0.0041 f 

( (12) 0.0041? 

((13) 0.0044;

Weight of 

KC1 taken.

grm.

( (14) 0.2091 

( (15) 0.2074

{ (16) 0.2059 

( (17) 0.2040

Mean.

grm. 

0.0041

Total weight of 

KC1 found.

grm.

0.2093 

0.2078

0.2059 

0.2041

Weight of NaCl found

in solution in 100 cm. 3

of amyl alcohol.

grm. 

0.0046" 

0.0050! 

0.0053| 

0.0055

Weight found 

in residue.

grm. 

' 0.2074

0.2059

0.2040

0.2015

Weight found 

in solution.

grm. 

0.0019 

0.0019 

0.0019 

0.0026

Derived from these figures we have:

(14)

(15) 

((16) 

1(17)

Loss of KClto

100 cm.3 of 

amyl alcohol.

grm. 

0.0049' 

0.00411 

0.0059 | 

0.0056

Mean.

grm. 

0.0051

Weight of KC1 found 

in solution in 100 cm. 3

of amyl alcohol.

grm.

. 0.0054' 

0.00531 

0.0059| 

0.0058

Mean.

grm. 

0.0051

Volume of residual amyl 

alcohol.

cm.3

35

36

32

45

Mean.

grm. 

0.0056

From these figures it appears that the total weight of chloride found 

is always a little greater than that taken, the mean increase being 0.0005 

grm. for sodium chloride and 0.0002 grm. for potassium chloride. It 

appears also that the residue left by the evaporation of the decanted 

and filtered amyl alcohol is greater than the loss put upon the chloride 

by the treatment: in the case of sodium chloride 0.0005 grm., in the 

mean, for every 50 cm.3 of amyl alcohol, which is about the quantity 

employed in the experiments; for potassic chloride 0.0002 grm., in the 

mean, for 40 cm.3 of amyl alcohol, which is approximately the quantity

(80)
OOOCH.J SEPARATION OF SODIUM FROM LITHIUM. 81

used in tha.t case. It will be seen, therefore, that there exists for both 

salts an exact coincidence between the mean total excess found and the 

difference between the figures which indicate the solubility of the salts 

for the two methods of determination; and, taking this fact in conjunction with the results of the evaporation of amyl alcohol in blank (the 

mean residue being 0.0004 grm. for 40 cm.3 , and 0.0005 grm. for 50 cm.3 ), 

it seems to be brought out pretty clearly that the former set of figures 

represents more exactly the solubility of the salts, though the difference 

between the two series is not great. Besting, then, upon the former 

determinations, the solubility of sodium chloride may be taken as 0.0041 

grm. in every 100 cm.3 of anhydrous amyl alcohol, or one part in 30,000 

parts by weight; and the solubility of potassium chloride, a little greater, 

is 0.0051 grm. to 100 cm.3 of amyl alcohol, or one part in 24,000 by weight.

The conditions under which the salts are acted upon are such as 

should insure the complete saturation of the solvent, and in this connection it is interesting to note that for the quantities of material 

employed the discrepancy between comparable figures never exceeds 

0.0005 grm.

In experiments (10), (11), and (14), (15), the alcohol was decanted and 

filtered at once while hot; in (12), (13), and (16), (1.7), it was cooled to 

30° C. before decanting; so it appears that the solubility of the salts is 

not influenced by changes of temperature within the range from 30° C. 

to 13200.

Used simply to wash the precipitate, amyl alcohol cannot, of course, 

exert an effect at all comparable with that manifested in the experiments which have been described, but to know, just what this action 

may be is important. Experiments (18) to (22) were undertaken, therefore, to elucidate this point.

Weighed amounts of the test solutions were evaporated nearly to 

saturation in small glass beakers, amyl alcohol added, and, as in the 

previous experiments, the whole heated until the salt had deposited and 

the residual alcohol had boiled quietly for some minutes at its ordinary 

boiling point, the liquid decanted, filtered under gentle pressure by 

means of a weighed perforated crucible and felt of asbestus, the filtrate 

measured, the residue dislodged with the aid of a rubbing-rod and transferred to the crucible and washed with anhydrous amyl alcohol, the 

washings being collected and measured. The crucible and contents 

were dried over a free flame turned low, so that the heat should not 

reach the melting point of the chlorides.

Weight of NaGl Error of cor- Volume of Volume of

Weight of Weight of found, corrected for rected weight residual amyl alcoNaCl taken. NaCI found, solubility in residual of NaCl amyl hoi in

amyl alcohol. found. alcohol. washings.

grm. grm. ' grm. grm. cm.3 cm.1

(18) 0.0947 0.0937 0.0947 O.'OOOO 24 '44

(19) 0.1080 0.1074 0.1083 0.0002+ 19 53 

Bull. 42 6 (81)
82 WASHINGTON LABORATORY. [BULL. 42.

Weight of KCl Error of cor- Volume of Volume of

Weight of Weight of found, corrected for rccted weight residual ainyl alcoKC1 taken. KCl found, solubility in residual of KCl amyl hoi in

amyl alcohol. found. alcohol washings.

grm. grm. grm. grm. cm. 8 cm. 3

(20) 0.1846 0.1837 0.1847 0.0001+ '20 60

(21) 0.1964 Q.1946 0.1961 0.0003 30 45

(22) 0.1857 0.1839 0.1854 0.0003 30 60

These results show very plainly that the solvent effect of anhydrous 

ainyl alcohol used for washing under the conditions described is trifling in the extreme, and may be neglected utterly providing the amount 

of the washing is not altogether disproportionate to the needs of the 

case.

We pass next to the consideration of the separation of the chlorides 

of sodium and potassium from lithium chloride. Weighed portions of 

the test solutions were concentrated and treated with amyl alcohol in 

the manner described until the precipitated salt was entirely free from 

water and the supernatant alcoholic solution of the lithium chloride 

boiled constantly at a point not far from that of the amyl alcohol employed. Then the liquid was cooled, a drop or two of strong hydro- 

.chloric acid was added in accordance with the evident suggestion of the 

preliminary experiments previously mentioned, and heat was again applied until the boiling had continued, as before, for some minutes at 

one point. The nitration, washing, drying, and weighing of the residue were effected as in experiments (18) to (22). In those of the experiments in which the lithium salt in solution was also determined, the 

end was accomplished by evaporating the nitrate and washings to dryness, treating the residue with sulphuric acid, and igniting and weighing as lithium sulphate. In the following table the weight of insoluble 

chloride actually found is given in one column, and this weight, corrected 

according to the data previously determined for the solubility of the 

chloride in the residual amyl alcohol, appears in the column adjoining. 

So also the weight is given of the lithium sulphate actually found, and 

an adjacent column contains the result of correcting this weight for the 

accompanying sodium or potassium sulphate, or both, upon the hypothesis that these salts are neutral sulphates after the ignition. In the 

case of quantities so minute the error which is introduced by such an assumption cannot be considerable, and in relation to this point Dittmar l 

maintains that comparatively large amounts of acid sodium or potassium 

sulphate may be reduced to the neutral salt by ignition simply. The 

figures of the column showing the weights of lithium chloride found are 

derived by calculation from the weights of lithium sulphate actually

1 Report on researches into the composition of ocean water, collected by H. M. S. 

Challenger during the years 1873-1876, p. 18.

(82)
GOOCH.] SEPAEATION OF SODIUM FEOM LITHIUM. 83

found. The other headings of the table are sufficiently intelligible 

without further explanation.

Weight of NaCl Error in Error in

Weight of Weight of found, corrected weight of corrected

NaCl taken. NaCl found, for solubility in 

amyl alcohol.

NaCl 

found.

Volume of amyl

alcohol used, 

weight of 

NaCl found. Rcaidual. Total.

(23)

(24)

(25)

grm.

0. 1089.

0. 1084

0. 1074

grm.

0. 1092

0. 1085

0. 1067

grm.

0. 1095

0. 1090

0. 1074

grm. grm. . cm.3 cm. 3

0.0003+ 0.0006+ 7 70

.0.0001+ 0.0006+ 12 80

0.0007 0.0000 18 90

Weight of 

LiCl taken.

grm.

(23) 0. 1298

(24) 0.1227 

(25) 0. 0116

Weight of 

KC1 taken.

grm.

((26) 0.2051 

(27) 0.2022

(28) 0. 2109

C29) 0.0984

Weight of 

LiCl taken.

grm.

(26) 0. 1256

(27) 0.1287 

(28) 0.0113

(29) 0.0113

Weight of 

NaCl taken,

grm.

(30) 0. 1053

(31) 0. 1051

Wfiio-hfnf \Wifrlitnf Corrected Error in Error in corTisng fn,iml nriTmml weight of weight of rected weight LisS04 found. LiCl found. LiCffound. LiCl found. of LiCl found.

grm. grm. gnn. grm. grm.

0.1682 0.1299 0.1296 0.0001+ 0.0002-

0.1592 0.1230 0.1225 . 0.0003+ 0.0002-

Volumo of amyl 

Weight of KC1 Error in Error in alcohol used. 

Weight of found, corrected weight of corrected 

KC1 found. for solubility in KC1 weight of Eesid- ,rnin , 

amyl alcohol. found. KC1 found. ual. lotaL

grm. grm. grm. grm. cm. 3 cm. 3

0.2036 0.2053 0/0015 0.0002+ 34 100 

0.2013 0.2032 .0.0009 * 0.0010+ 37 100

0.2096 0.2104 0.0013 0.0005 16 100

0.0970 0.0980 0.0014 0.0004 20 90

Wfiiirhtof TVmtrhtnf Corrected Error in Error in corTisng£,,mi TirT^nnml "flight of weight of rected weight of LuSOaound. LiCl found. LiC1fefound. LiCl found. LiCl found.

grm. . £riu. grm. Qsr&t grni0.1638 0.1265 0.1248 0.0009+ 0.0008-

0.1677 0.1296 0.1277 0.0009+ 0.0010-

v

TTT Weight . i_. n Weight of Corrected weight TT i t -\ ot isTom^Lirr1 ! nf KTOPI j^iroi Volume of amyl 

KC1. taken. foutd7 found. alcohol used.

Residual. Total.

grm. grm. . grm. cm.3 cm.3

0.1031 0.2064 0.2084 22 100

0.0945 0.1988 0.2003 16 80

(30)

(31)

Weight of 

LiCl taken.

grm. 

0. 0113 

0.0113

Error in weight 

of NaCl + KCl found.

grin.

0. 0020 

0. 0008 

Error in corrected weight 

of NaCl + KCl found.

grm. 

0. 0000 

0.0007+

It will be noticed that in experiments (23), (24), (26), and (27) the 

corrected error in the weight of the insoluble chloride has a positive

(83)
84 WASHINGTON LABORATORY. [BULL. 42.

value, ranging from 0.0002+ grin, to O.OOlO+,grm., with a mean of 

0.0006+ grm.; and that in experiments (25), (28), (29), (30), and (31), 

the mean error is negative, amounting to less than 0.0001 grm., with 

a range from 0.0005 grm. to 0.0007+ grm.

The point of difference between these two series of experiments is 

the amount of lithium chloride introduced, only a tenth of that used in 

the former being employed in the latter. It is plain that, when we are 

dealing with the larger amount, a larger portion tends to remain behind with the insoluble chloride ; r and here again we meet, though to a degree comparatively harmless, the inclination of lithium chloride to yield 

chlorine and pass to the form of lithium hydrate. When the lithium 

chloride is present in small amount, as in the latter group of experiments, there can be little left undissolved; and the spectroscope confirms the evidence of the figures of analysis as to the perfectness of the 

separation by showing in such cases either no lithium at all or merely 

fugitive traces. If a single precipitation is sufficient to effect a satisfactory separation of the insoluble chlorides from small amounts of 

lithium chloride,-it is natural to suppose that a repetition of the precipitation would be beneficial in treating larger quantities of lithium chloride.

Experiments (32) to (37) illustrate the effect of a double precipitation. The chlorides were brought to filtration as before, the liquid 

was decanted as completely as possible, the precipitate washed slightly 

by decautation and redissolved in a little water, and the round of boiling, filtering, drying, and weighing carried to the end as before, care 

being taken to repeat the treatment with a drop of hydrochloric acid 

during the process of boiling. The two portions of residual ainyl alcohol were measured apart, as well as the washings.

(32)

(33)

(32)

(33)

(34)

(35)

(36)

(37)

Weight of 

NaCl taken.

grm.

0. 1166

0. 1139

Weight of 

LiCl taken.

grm.

0. 1287

0. 1347

Weight of 

KC1 taken.

grm.

0. 1155

0. 1034

0.1914

0. 1953

Weight of 

Nad found

grm.

0. 1163

0. 1127

Weight of 

Li2S04 found.

grm.

0. 1662

0. 1759

Weight of 

KC1 found.

grm.

0. 1142

0. 1017

0. 1905

0.1939

Corrected 

weight 

of NaCl 

found.

grm.

0. 1169

0. 1132

Weight of 

LiCl found.

grm.

0. 1284

0. 1359

Corrected 

weight 

of KC1 

found.

grm.

0. 1152

0. 1028

0. 1912

0. 1950

Error 

in weight 

of NaCl

found.

grm.

0. 0003-

0. 0012-.

Corrected 

weight of 

LiCl found.

grm.

0. 1280

0. 1353

Error 

in weight 

ofKCl 

found.

grm.

0. 0013-

0. 0017-

o: 0009-

0.0014-

.(84)

Error in 

corrected 

weight of 

NaCI. found.

gr.m.

0. 0003+

0.0007-.

Error in 

weight of 

LiCl found.

grm.

0.0003-

0. 0012+

Error in 

corrected 

weight of 

KC1 found.

grm.

0.0003-

0. 0007-

0. 0002-

0. 0003-

Volurae of amyl 

alcohol used.

Residual. T(jtal

cm.3 cm.3 cm.3

88 .150

57. 150

Error in corrected 

weight of 

LiCl found.

grm.

0.0007-

0. 0006+

Volume of arnyi 

alcohol used. 

Kesidual. ^tal.

cm. 3 cm. 3 cm.3

10 10 100

10 12 200

3 11 90

4 18 110
GOOCH-l SEPARATION OF SODIUM FEOM LITHIUM. 85

]

(34)

(35)

(36)~

(37)

Weight of 

LiCl taken.

grm.

0. 1125

0. 1251

0. 1263

0. 1282

Weight of 

LizS04 found

grm.

0. 1475

0. 1649

Weight of 

.LiCl found.

grm.

0. 1139

0. 1274

Corrected 

weight of 

LiCllfound.

grm.

0. 1128

0. 1162

Error in 

weight of 

LiCl found.

grin.

0. 0014+

0. 0023+

'

Error in corrected 

weight of 

LiCl found.

grm.

0. 0003+

0.0011+

Thus it appears that, in the separation of the insoluble chlorides from 

the larger amounts of lithium chloride, the residue of two precipitations 

is substantially free from lithium.

For the sake of bringing the data in hand more directly into comparison, the corrected errors of the preceding determinations are tabulated 

again in the following statement:

experiment. of No.

(23) 

(24) 

(20; 

(27) 

(25) 

(28) 

(29) 

(30) 

(31) 

(32) 

(33) 

(34) 

(35) 

(30) 

(37)

Chloride.

NaCl. ........

KC1. .....".....

NaCl.. .......

KC1. .........

NaCl+KCl...

NaCl. ........

KC1-... ......

Approx. mean .

Corrected error of insoluble cliloride 

Precipitated 

once from 

about 0. 13 

.gnu. of 

LiCl.

Qrm. 

0. 0006+ 

0. 0006+ 

0. 0002+ 

0. 0010+

0. 0006+

Precipitated 

onne from 

about 0. 013 

grm. of 

LiCl.

Grm.

0. 0000 

0. 0005-

0. 0004-

0. 0000 

0. 0007+

.

0. 00004-

Precipitated 

twice from 

about 0. 13 

grm. of 

LiCl.

Grin.

0. 0003+ 

0. 0007- 

0.0003- 

0. 0007- 

0. 0002-

0.0003-

0. 0003-

Error in 

corrected 

weight of 

LiCl.

Grm. 

0. 0002- 

0. 0002- 

0. 0008- 

0. 0010-

0. 0007- 

0. 0006+ 

0. 0003+ 

0.0011+

I

Approximate 

mean error 

of LiCl.

Grm. 

 0. OQ05-

1 0.0003 +

Few processes in analytical chemistry are capable of yielding results 

more exact than these. The separation of from 0.1 grm. to 0.2 grm. of 

sodium or potassium chloride from a tenth of its own weight of lithium 

chloride is practically perfect in one operation, a'nd from its own weight 

of lithium chloride the parting may be effected satisfactorily by two precipitations.

The points to be observed in executing the method may be recapitulated as follows :

To the concentrated solution of the chlorides, amyl alcohol is added 

and heat is applied, gently at first to avoid danger of bumping, until 

the water disappearing from solution and the point of ebullition rising

(85)
86 WASHINGTON LABORATOEY. [BULL.42.

and becoming constant for some minutes at a temperature which is 

approximately that at which the alcohol boils by itself, the chlorides of 

sodium and potassium are deposited and lithium chloride is dehydrated 

and taken into solution. At this stage in the operation the liquid is 

cooled and a drop or two of strong hydrochloric acid is added to reconvert traces of lithium hydrate in the deposit, and the boiling is continued until the alcohol is again free from water. If the amount of 

lithium chloride present is small it will now be found in solution, and 

the chlorides of sodium and potassium will be in the residue, excepting 

the traces, for which correction will be made subsequently. If, however, the weight of lithium chloride present exceeds ten or twenty 

milligrams, it is advisable at this point, though not absolutely essential 

to the attainment of fairly correct results, to decant the liquid from the 

residue, wash the latter a little with anhydrous amyl alcohol, dissolve 

in a few drops, of water, and repeat the separation by boiling again in 

amyl alcohol. For washing, amyl alcohol previously dehydrated by 

boiling is to be used and, the filtrates are to be measured apart from 

the washings. In filtering it is best to make use of the perforated 

crucible and asbestus felt and apply gentle pressure. The crucible 

and residue are ready for the balance after drying for a few minutes 

directly over a flame turned low. The weight of insoluble chlorides 

actually obtained in this manner is to be corrected by the addition of 

0.00041. .grm. for every 10 cm.3 of amyl alcohol in the filtrate, exclusive 

of washings, if the insoluble salt is entirely sodium chloride, 0.00051 

grm. for every 10 cm.3 if potassium chloride constitutes the residue, and, 

if both sodium and potassium chloride are present, 0.00092 grm.; but, 

as in the experiments described, the entire correction may in any case 

be kept within narrow limits, if due care be given to the reduction of 

the volume of residual alcohol before filtration. The filtrate and washings are evaporated to dryness, treated with sulphuric acid, the excess 

of the latter is driven off% and the residue ignited to fusion and weighed. 

From the weight thus found the subtraction of 0.00050 grm. is to be 

made if sodium chloride constitutes the precipitate, 0.00059 grm. if potassium chloride alone is present in the residue, and 0.00109 if both of 

these chlorides are present, for every 10 cm.3 of filtrate, exclusive of 

washings.

Amyl alcohol is not costly, the manipulations of the process are easy, 

and the .only objectionable feature the development of the fumes of 

amyl alcohol is one) which is insignificant when good ventilation is 

available.

The-process has been used for some months frequently and successfully, by others as well as myself, for the estimation of lithium in 

waters and minerals.

In this connection it seems best to include the record of certain experiments looking to the separation of the chlorides of sodium and

(86)
QOOCH.] SEPARATION OF SODIUM FROM LITHIUM. 87

potassium from the chlorides of magnesium and calcium. The behavior 

of magnesium chloride toward amyl alcohol is of interest, both with 

reference to the problem of separating sodium and potassium from 

lithium and magnesium when the latter are associated and as concerns 

the parting of the alkalies from magnesium alone a matter which is 

by no means perfectly simple and experiments (38) to (41) touch upon 

this topic.

The chlorides of sodium and potassium were weighed, as before, in 

solution; the magnesium chloride was obtained by dissolving in hydrochloric acid the oxide specially.prepared and weighed as such. The 

process of treatment was identical with that just described for the separation of the chlorides of potassium and sodium from lithium chloride.

(38)

(39)

(40)

(41)

Weight of 

NaCl taken.

grin.

0.1030

0.0967

0.1030

0.1053

Weight of 

KC1 taken.

grin.

0.1064

0.1024

0.1073

0.1093

Weight of 

NaCl+KCl 

found.

grm.

0.2079

0.197G

0.2071

0.2114

Corrected 

weight of 

NaCl+KCl 

found.

grm.

0.2100

0.200G

0.2093

0.2142

Volume of amyl 

alcohol used. 

Residual. Total.

I. II.

cm.3

23

33

13

12

cm.3

--

-.

11

18

cm.3

120

100

100

100

(38)

(39)

(40)

(41)

Weight of 

MgO taken.

grm.

0.1000

0.1000

0.1000

0.1000

Error in weight of 

NaCl+KCl found.

grm.

0.0015-

 0.0015-

0.0032-

0.0032 

Error in corrected weight 

of tfaCl+KCl found.

grm. 

0.0006+ 

0.0015+ 

0.0010- 

0.0004 

The residues of experiments (38) and (39), in which the separation 

was made by a single precipitation, carried traces of magnesia; those 

of (40) and (41), in which two precipitations were introduced, were found 

to contain in the one case no magnesia and in the other an unweighable 

trace; These results point out a method by which the chlorides of sodium and potassium may be obtained free from magnesia, while the 

small amounts of the former which pass into solution with the magnesium chloride are capable of accurate estimation; and there seems to 

be no reason why the separation of these alkaline chlorides from, magnesium chloride and lithium chloride occurring together should not be 

effected in one operation, and the parting of the latter salts brought 

about by the familiar method of precipitating the magnesium in the 

cold as ammonium-magnesium phosphate.

Experiments (42) to (47), upon the separation of sodium and potassium from calcium by the action of amyl alcohol on the chlorides, yielded 

the figures of the following table. The mode of treatment was identical 

with that of the experiments with magnesia just described, excepting

(87)
88 WASHINGTON LABORATOKY. [BULL. 42.

only the substitution of pure calcium oxide, specially prepared, for magnesium oxide.

(42)

(43)

(44)

(45)

(46)

(47)

Weight of 

NaCl taken.

grm.

0. 0859

0. 1018

0. 1096

0.0985

0. 0914

0. 0997

Weight of 

KC1 taken.

grin.

0. 1126

0. 1057

0. 0962

 0. 1018

0. 1104

0. 1100

Weight of 

NaCl+KCl 

found.

grm.

0. 2177

0. 2217

0.2112

0. 2113

0. 1968

0. 2080

Corrected 

weight of 

NaCl+KCl 

found.

grm.-

0. 2195

0. 2235

0. 2130

0. 2130

0/2000

0. 2089

E 

I.

cm. 1

20

20

20

19

20

3

Volume of amyl 

alcohol used. 

Kesidual. Total. 

I. II.

cm. 3 cm. 3

20 

20

20

19

20 15

3 7

crn-e

100

100

100

100

100

90

(42)

(43)

(44)

(45)

(46)

(47)

Weight of 

CaO taken.

grm. 

0.1000 

0.1000 

0.1000 

0.1000 

0.1000 

0.1000

Error in weight of Error in corrected weight 

NaCl+KCl found. of NaCl -f-KCl found.

grm.

0. 0192+ 

0.0142+ 

0. 0054+ 

0.0110+ 

0.0050- 

0. 0017-

grm.

0. 0210+ 

0. 0160+ 

0.0072+ 

0.0127+ 

0. 0018- 

0.0008-.

From these results it is plain that it is a far more difficult matter to 

dehydrate and dissolve calcium chloride than to dehydrate and dissolve 

either magnesium chloride or lithium chloride. The separation of the 

chlorides of sodium and potassium from calcium chloride cannot be accomplished, for the quantities employed in these experiments, by a 

single precipitation; but the repetition of the treatment is effective. 

In the residues of experiments (46) and (47) calcium could not be found 

by the test with ammonium oxalate. In a case, therefore, in which the 

separation of sodium and potassium from lithium, magnesium, and calcium in one operation should be desirable, the end may probably be 

accomplished by means of the process here described.

Certain preliminary experiments with the nitrates of the bases under 

discussion indicate that these are susceptible of similar separation by 

the action of ainyl alcohol; and the wide applicability in analytical 

operations of the general principle involved the dehydrating of.salts 

by means of amyl alcohol or other liquid of high boiling point and appropriate solvent action can scarcely be a matter of doubt.

(88)
THE INDIRECT ESTIMATION OF CHLORINE, BROMINE, AND IODINE 

BY THE ELECTROLYSIS OF THEIR SILVER SALTS, WITH EXPERIMENTS ON THE CONVERTIBILITY OF THE SILVER SALTS BY 

THE ACTION OF ALKALINE HALOIDS.

By J. EDWARD WHITFIELD.

In the absence of trustworthy methods for the direct quantitative 

separation of bromine and chlorine, it is usual to employ some process 

for the conversion of the mixed silver salts to a common condition. 

Both the reduction to silver by hydrogen and the conversion of the 

bromide to chloride by heating in an atmosphere of chlorine are attended with loss by volatilization and mechanical transfer, and the 

possible inaccuracy of both the processes is such that they can scarcely 

be considered as available for the estimation of small amounts of 

either cbnstituent in the presence of large amounts of the other.

Of all such methods the electrolytic analysis of the mixed and fused 

silver salts as proposed by Bolley1 and more recently introduced and 

tested by Kinnicutt2 is probably the best, though according to Finkener 3 perfect decomposition is difficult to obtain by this method and 

there is danger of volatilization and partial change of the silver salts in 

the fusion.

Kinnicutt's test analyses of the fused salts show, for silver chloride 

and silver bromide each by itself, errors of 0.0006 grm. to 0.0003+grm. 

on amounts varying from 0.7 grm. to 1.8 grm.; and for the mixed silver 

chloride and bromide errors from 0.0010 grm. to 0.0012+grm. with 

a mean of 0.0006+grm.on weights varying from 2 grm. to 2.8 grm.

These figures represent the sum of the errors from the weighing of 

the fused chloride to the weighing of the deposit of silver and do not 

include errors made iu the precipitation, filtration, transfer to the crucible, and fusion.

A method in which the decomposition of the silver salts may be effected without fusion, and which would at the same time place the errors 

of filtration, preparation for weighing, and subsequent electrolysis at a

1 Dingl., Pol. Jour., CLI, p. 46.

2 Am. Chem. Jour., IV, p. 22.

, 3 Kose-Finkener, Quant. Anal., II, p. 621.

(89) 89
90 WASHINGTON LABORATORY. (BULL. 42.

minimum, seems to be desirable, and a promising line of investigation 

was suggested by Luckow's assertion1 that from the solution of silver 

chloride in potassium cyanide the silver may be thrown down completely.

Luckow gives no figures, excepting a common mean of all determinations by the precipitation from the cyanide solution and the decomposition of the solid chloride on the negative pole of the battery under 

sulphuric acid; so that the first experiments were made to test the accuracy of the battery process under these conditions.

In experiments (1) to (5) silver chloride was the starting point. In 

(1) to (3) the freshly precipitated and carefully washed chloride was 

dried to a constant weight in a platinum dish, protected from the light, 

at a temperature of about 150° 0., dissolved in potassium cyanide and 

electrolyzed after the addition of a little sodium hydrate, preliminary 

analyses having seemed to indicate that the presence of sodium hydrate 

affected the deposition favorably. In all subsequent experiments 

ammonia, which was found to be Of equal service, was used instead of 

sodium hydrate.

In experiments (4) and (5) the chloride was converted, previous to 

electrolysis, into the bromide by solution in potassium cyanide, the addition of potassium bromide, and precipitation by sulphuric acid, as will 

be described later, and the precipitate redissolved in potassium cyanide, 

the object being to test the action of the battery upon the cyanide solution of the silver bromide. * '

Ag Cl taken. Silver found. Silver calculated. Error.

grm. grin. grm. grm.

(1) 0.1565 0.1177 0.1178 0.0001 

(2) 1.3004 0.9785 0.9787 0.0002 

(3) 2.2C57 1.7047 1.7051 0.0004 

(4) 0.7472 0.5618 0.5624 0.0006 

(5) 0.2854 0.2133 0.2147 0.0014 

These results, as far as they go, are satisfactory. Similar tests upon 

the electrolysis of silver bromide and silver iodide in the cyanide solution 

were undertaken, but it was thought advisable to combine incidentally 

with the tests of the battery process an examination of the method recently proposed by Maxwell-Lyte2 for the direct conversion of silver 

chloride to the bromide and thence to the iodide.

Field 3 was the first to propose a quantitative conversion of silver 

chloride to the bromide by digesting the former in potassium bromide, 

and the change of the chloride or bromide to the iodide by the action of 

potassium iodide upon these salts. This method has been variously 

criticised and finally abandoned as an inaccurate process,4 though so

1 Dingl.,'.Pol. Jour., CLXXVIII, p. 43. 3 Jour. Chem. Soc., 10, p. 234.

2 Chem. News,Vol. 49, p. 3. 4 Rose-Finkeuer, loc. cit.

(90)
WHIT .] IN-DIRECT ESTIMATION OF CHLORINE, ETC. 91

far as concerns the conversion of the chloride and bromide to tbe iodide 

Siewert1 shows it to be exact.

Maxwell-Lyte's method of proceeding, depending upon identically the 

same principle which Field attempts to utilize, consists in the solution 

of the silver haloid salts in potassium cyanide, the addition of potassium 

bromide, the decomposition of the potassium cyanide by means of sulphuric acid, with the consequent precipitation and weighing of the silver 

bromide mixed with the iodide of the original mixture the resolution 

of this precipitate in potassium cyanide, the addition of potassium iodide, 

the decomposition of the cyanide as before with sulphuric acid, with 

the formation of a precipitate, which is presumably pure silver iodide 

and to be weighed as such.

To convert the chloride to the bromide Maxwell-Lyte uses a weight 

of potassium bromide equal to the weight of the silver chloride taken, 

and, to change the bromide to the iodide, a weight of potassium iodide 

one and a quarter times as great as the original weight of the silver 

chloride.

In the following experiments these amounts have varied widely, but 

the proportion of alkaline haloid salts employed is given for each case 

in the tabular statement.

The starting point was generally freshly precipitated silver chloride, 

but in the last three cases pure silver, this being dissolved in nitric 

acid, precipitated with potassium bromide (two equivalents), and the 

precipitate dissolved in potassium cyanide, converted to the iodide in 

the manner described, and weighed, the object of this being to test the 

convertibility of silver bromide to 'silver iodide.

In most cases the final precipitate after weighing was electrolyzed, 

so as to have a more perfect control upon the results of the conversion 

process, and at the same time to test the battery method additionally.

The bromide and iodide of silver were precipitated hot from dilute 

solutions, which were cooled arid allowed to stand over night to settle 

before filtering,

Filiations were made by the use of the Gooch crucible with gentle 

pressure. The silver salts were dried directly over a low Bunsen flame 

at a temperature far below the melting point, and dissolved, after weighing, by introducing crucible and asbestus into a strong solution of potassium cyanide and heating, the time necessary for the solution varying from a few minutes to several hours, according to circumstances. 

In some cases traces of reduced silver were found with the asbestus 

and were recovered by treating the felt with nitric acid and washing, 

the filtrate and washings being added to the main solution.

The deposition of silver was made in the platinum dish of 100 cm.3 

capacity, which held the solution, and the current found most suitable 

was (as Luckow originally ecommended)2 developed by four Meidinger

'Zeitschr. anal. Chern., 7, p. 4G9. 2 Loc. cit.

(91)
92 WASHINGTON LABORATORY, [BULL. 42.

cells of large size. With solutions of the volume named and the area of 

the negative electrode employed, it was found advisable not to attempt 

to treat more than two grammes of the silver salt.

The solution was decanted immediately on the stopping of the current, or, better, siphoned off while the battery connections were still 

unbroken, and washed with distilled water to prevent the solvent action. 

of the cyanide on the ^deposit.

(6)

(7)

(8)

(9)

(10)

(11)

(12)

(13)

(14)

(6)

(7) 

(8) 

(9) 

(10)

(11) 

(12)

(13) 

(14)

(15)

(16)

(17)

(18)

(19)

(15)

(16)

(17)

(18)

(19)

AgCl taken.

grm.

0. 3260

0. 3093

1. 3801

0. 2091

0. 6846

1. 1625

1. 1734

0. 3501

0. 4178

AgCl taken.

grm.

0. 3260

0. 3093 

' 1.3801 

0. 2091 

0. 6846 

1. 1625 

1. 1734

0. 3501 

0.4178

AgCl taken.

grm.

0. 6996

0. 7587

0. 6710

0.2515

0. 6501

AgCl taken.

grm.

0. 6996

0. 7587

0. 6710

0.2515

0. 6501

AgBr found. AgBr calculated. Error.

grm.

0.4227

0. 4023

1. 8041

0. 2723

0. 8909

1. 5202

1. 5310

0. 4553

0. 5468

Silver found.

grm.

0. 2443

1. 0385

0. 5137

0. 8829

0. 2634

Agl found. Ag

grm.

1. 1451

1.2429

1. 0992

0.4118

1. 0646

Silver found.

grm.

0. 5255

0. 5691

0. 5042

0. 1892

0. 4892

(92)

grm. grm.

0. 4270 0. 0043 

0.4052- 0.0029 

1. 8080 ' 0. 0039 

0.2739 0.0016 

0.8968 0.0059 

1.5230 0.0028 

1.5372 0.0062 

0. 4586 0. 0033 

0. 5473 0. 0005 

Silver calculated.

grm.

0. 2453

i

1,0386

0. 5152

0. 8831

0.2634

I calculated. Error.

grm. grm.

1.1456 0.0005 

1. 2424 0. 0005 +

1. 0988 0. 0004 +

0.4118 0.0000

1. 0646 0. 0000

Silver calculated.

grm.

0. 5265

0. 5710

0. 5050

0. 1892

0. 4892

Equivalents of 

K Br taken.

'

2

2

2

10

'10

20

20

29

29

Error.

grin.

0. 0010 

0.0001 

0. 0015 

0.0002 

0. 0000

Equivalents 

taken of KI.

2

2

10

10

10

Error.

grm.

0. 0010 

0.0019 

0. 0008 

0. 0000

0. 0000
WHITFIELD.] INDIRECT ESTIMATION OF CHLORINE, ETC. 93

A T , Equivalent q:i wnr 

Silver taken. Agl found. ^^ Error. taken ^ Error.

01 Jx J..

(20).

(21)

(22)

grm.

0. 5418

0. 3750

0. 4078

grm.

1. 1790

0. 8154

0. 8859

grm.

1. 1789

0. 8159

0. 8873

grm.

0. 0001 +

0.0005 

0.0012 

2

2

10

0. 5417

0. 3746

0. 4077

grm.

0.0001 

0. 0004 

0. 0001 

From these experiments it appears that the deposition of silver from 

the cyanide solution of the chloride, bromide, or iodide is exceptionally 

exact. The tendency of the process, however, is to yield low results, 

and yetj in spite of the multiplicity of operations through which the 

original material has been passed in the attempt to settle two questions 

at once, the deficiency is not very great, being 0.0005 grm. in the mean 

of eighteen determinations, with a maximum value of 0.0019 grm.

The conversion of silver phloride to silver bromide by the method 

proposed by Maxwell-Lyte, like its predecessor, is too imperfect to be 

worthy of trust, but the experiments indicate unmistakably that the 

change of silver chloride or silver bromide to silver iodide is sufficiently 

complete to afford the basis of a good analytical method.

The indirect estimation of chlorine and bromine, chlorine and iodine, 

or bromine and iodine in presence of one another may be effected satisfactorily, therefore, by precipitating both together as silver salts, filtering on asbestus, washing and drying at 150° C., weighing, dissolving the 

residue in potassium cyanide, and either electrolyzing the solution to 

determine the silver or precipitating the silver as iodide again, filtering 

upon asbestus, washing, drying, and weighing.

In a mixture of all three halogens the iodine is first to be separated 

by lino wn methods, and the chlorine and bromine are to be indirectly 

estimated as described.

(93) ' .
ON TWO NEW METEORIC IRONS AND AN IRON OF DOUBTFUL

NATURE.

BY E. B. EIGGS.

THE GRAND RAPIDS METEORITE.

In the American Journal of Science (Vol. XXVIII, 3d ser., p. 297), 

Prof. J. E. Eastman called attention to an iron of probably meteoric 

origin, found near Grand Eapids, in Walker Township, Kent County, 

Michigan.

At the time a rough analysis was made on scanty material, identifying it as a true meteoric iron. Since then the iron has come into the 

keeping of the National Museum and a more careful analysis has been 

made, with the following results:

Per cent. 

Fe..................--'.................................- 88.71

Ni...................................................... 10.69

Cu...................................................... .07

Mg...................................................... .02

P........................................................ .26

S........................................................ .03

C (combined)............................................ .06

Graphite ................................................ .07

99.91

The meteorite weighed originally about 52 kilograms. It is a compact mass of great apparent homogeneity, possessing a specific gravity 

of 7.87. One of the sections disclosed, however, a small nodule about 

one centimeter in diameter. This not being available for analysis, its 

composition remains undetermined.

Etched with nitric acid, the iron gives Widmanstiittian figures very 

like those of the Eobertson County meteorite, though of a finer character, jSo fracture lines were observed.

(94) 94
BIGGS.] TWO NEW METEOKIC IKONS, ETC. 95

FIG. 4. Grand Rapids meteorite.

FIG. 5. Etched surface of Grand Ilapids meteorite.

THE ABEKT IKON.

This meteorite was found unlabeled in a collection of minerals made 

by the late Col. J. J. Abort, and was presented to the National Museum 

by his son, Mr. J. T. Abert. The iron, evidently not a fragment, weighed 

originally 456 grammes, and had a specific gravity of 7.89. A cross section measured 50 by 37 millimeters.

(95)
96 WASHINGTON LABORATORY. (BULL. 42. 

An analysis gave it the following composition:

Per cent. 

Fo...................................................... 92.04

Ni...................................................... 7.00

Co...................................................... 0.68

P....................................................... 0.08

S ...................................................... 0.01

C (combined)........................................... 0. 02

Graphite ............................................... 0.03

99.86

Nitric acid brought out very characteristic Widmanstattian figures, 

of the same octahedral marking with, though somewhat coarser than, 

those of the Grand Eapids meteorite. The fracture is distinctly octahedral.

FIG. 6. Etched surface of Abert meteorite (actual size of section).

AN IRON OF DOUBTFUL NATURE.

This iron was found on the farm of A. L. Hodge, 3 miles southwest of 

New Market Station, Jeiferson County, Tennessee. It is from a region 

full of small iron furnaces, whence have come a number of the pseudometeorites, among others the Hominy Creek, Eutherfordton, and Campbell County irons. Special inquiries were therefore made by Prof. Ira 

Sayles, who obtained the specimen, regarding the presence of furnaces 

in the vicinity. So far as could be learned, that locality was free from 

them. Full of cavities, the iron is characterized by great hardness, defying the use of saws. With a specific gravity of 7.61, it weighed 640 

grammes. Fragments, however, had evidently been broken off from it.

(96)
RIGGB.] TWO NEW METEORIC IRONS, ETC. 97 

The following are the results of an analysis :

Per cent.

Fe..................................................... 88.27

Ni........................!............................ 0.76

Co .................................................... 0.19

Cu .................................................... 0.03

As...................................................... Trace

Ma .................................................... 6.73 '

Mg.................................................... 0.14

P....................................................... 1.80

Si..................................................... 0.15

C (combined) .......................................... 1.46

Graphite....!.......................................... 0.86

100.39

Treated with nitric acid, the polished surface developed quite fine 

markings not unlike Widmanstattian figures.

Its high percentage in manganese is possibly an objection (not by 

any means all sufficient) to ascribing to it a meteoric origin. The presence of manganese, and in considerable quantities, is not so uncoumion 

as many think. The Claiborne and Bitburg meteorites, both of unquestioned origin, contain respectively 3.24 per cent, and 4 per cent. Furthermore, while the presence of nickel and cobalt proves nothing, so large an 

amount of phosphorus is not common in a furnace product.

(97) 

Bull. 42 7
THE EFFECT OF SUDDEN COOLING EXHIBITED BY GLASS AND BY 

STEEL, CONSIDERED BOTH PHYSICALLY AND CHEMICALLY.!

BY C. BARUS AND V. STROUHAL.

§ I. THE STRAIN IMPARTED BY SUDDEN COOLING, AND ITS RELATIONS

TO TEMPERATURE.'

INTRODUCTION.

In Bulletin 35 we communicated a series of results on the structure 

of steel of a given kind, tempered hard. They showed, in general, that 

from the circumference to the axis of a quenched, non-filable, steel cylinder hardness continually diminishes ; that the first filable strata are 

encountered at a distance of about lcm below the surface. Moreover, 

jis hardness decreases, the density of the elementary conaxial cylindrical shells increases, and in proportion as the layers become more and 

more nearly or easily filable the density is found to approach the density 

of soft steel. From an examination of rods of different diameters (2em to 

3cm ) it appears, steel of a given kind presupposed, that the hardness at 

a point is essentially dependent on the distance of the point below the 

surface. The rate at which sudden cooling takes place must be similarly conditioned. Hence it is permissible to associate the one phenomenon with the other and to state that the hardness in a given point 

below the surface is dependent on the rate at which cooling there takes 

place. This point of view is suggestive; structure investigations may 

be made to furnish us the best means we know for the comparison of 

hardness and rate of cooling.

The results cited apparently make sad havoc with physical theories of temper. They seem indeed to be fatally at variance with the 

usually accepted views, viz: that in hard tempered steel an abnormally 

dense shell is arched around an abnormally rare core, the two states of 

strain mutually conditioning each other. The data may even be looked 

upon as'furnishing evidence sufficient to prove the total absence r of 

strain. It is the object of the present section to investigate in what 

measure this evidence is critically sufficient; if it be insufficient, to 

state the nature and relations of the strain effect of quenching somewhat more clearly than we were able to do in our earlier work.

! Our earlier work on the iron carburets will be found in Bulletins Nos. 14,27, and 35.

(98) 98
BABUB AMD-BtaouHAi,.] SUDDEN COOLING OF GLASS AND STEEL. 99

In our little book on the iron carburets 1 we endeavored to contrast the 

respective merits of chemical and physical theories of temper, usiug for 

this purpose all the data known to us, as well as special results of our 

own. The deduction seemed warranted that hardness and strain are 

distinct and separate properties of a tempered iron carburet f that they 

need not necessarily coexist. Leaving therefore hardness pure to be 

explained chemically, we inferred that the category of electrical and 

magnetic phenomena exhibited by steel on passing from hard to soft 

are mainly referable to changes in the character and intensity of the 

strain which the tempered rod carries. We accepted the theory of a 

dense shell and a rare core as being the most satisfactory and elegant 

conception of the strain in question, with the proviso 3 that u it must 

be regarded as a mere diagram of the essential features of the vastly 

more complicated structure of the glass-hard rod." These conditions 

premised, we finally interpreted all variation of Strain produced by annealing as the combined effect of changes of the viscosity of steel due to 

temperature and of interference of thermal expansion with the said 

strain.

The experimental question which we are endeavoring to elucidate 

may therefore be succinctly put as follows:

(1) With what degree of sensitiveness do the variations of the density 

of the rod, as a whole, indicate the corresponding variations of strain?

(2) Is it possible successively to remove layer after layer of a rod without materially changing the character and intensity of the strain which 

the rod is supposed to carry ?

(3) In how far does the actual structure of tempered steel differ from 

the diagrammatic distribution of density above assumed ?

(4) Does the process of sudden cooling impart strain alike in kind 4 

but differing enormously in degree to all substances?

In our paper on structure we had the second and third of these points 

principally in mind. We were unable to obtain direct and decisive evidence of the occurence of shrinkage during the removal of shells from 

a hard steel rod. But since the structure of steel differs so largely with 

the kind of steel operated upon, we do not regard our experiments as 

made in sufficient number to be conclusive. An examination of the 

density of the elementary shells shows that the character of the density 

at any point regarded as a function of the distance of a point below 

the surface is harmonic.5 To investigate this relation it is unfortunately 

necessary to make the measurements for thin (£mm ) shells. Hence the

'Bull. U. S. Geol. Surv., No. 14, p. 76, 1885.

2 Id., pp. 103, 197 . .

3 Bull. U. S. Geol. Surv., No. 14, pp. 95-98

4 We do not necessarily refer to mere volume expansion here. See Wriglitsou, Jour. 

Iron and Steel Inst., II, p. 418, 1879.

5 Bull, No. 35, U. S. Geol. Surv., p. 32, 1886.

(99)
100 WASHINGTON LABORATORY. [BULL. 42.

mean amplitude of vibration and the limits of the unavoidable errors of 

observation are of the same order. To discriminate between the periodic 

effect of temper, which may show regular or irregular periodicity, and the 

apparently periodic distribution of mere errors of observation is difficult and requires very nice and careful observation. In Bulletin 35 we 

attempt to arrive at this discrimination by making minute comparisons 

of the structures of rods of the same kind of steel and of the same 

or of different diameters. This procedure is excessively laborious; it 

calls for a detailed- construction of the relation of the density and the 

position of the points along any given radius of the rod and subsequent examination of the properties which the divers diagrams have in 

common. We have gathered many data, but the work is as yet incomplete, and the reader desiring further information will have to be referred 

to Bulletin 35, Avhere the whole subject is discussed. Experiment on 

the fourth of the above topics we have now in progress and shall publish 

later. This narrows the purposes of this paper to the consideration of 

the first and most important of the above points, viz: In what degree 

the density of a hard steel rod at different points, even when measured 

with all attainable accuracy, is sufficiently sensitive to represent the 

character, relations, and intensity of the temper strain.

DENSITY AND RESISTANCE (STRAIN) OF TEMPERED STEEL.

Experimental results. The discussion may be appropriately commenced by an examination of the variation of density of steel successively annealed from hard to soft. Our experiments on this subject, 

made in some number, are detailed in Bulletin No. 27, U. S. Geological 

Survey, and from this we select a digest of data sufficient for the construction of the following graphic comparison, a comparisen which did 

not fall properly within the scope of the inquiry in Bulletin No. 27, 

and hence was there omitted. It is necessary to reiterate that the dimensions of the steel rods used Avere as follows:

TABLE I.

No.............................

Average length of pieces (cm) ....

T

5.3 

1

i. a

ii.

10.1

i

0.58

55 to 60

61to63

2.5 

21

2.5 

13

0.23

36 to 36,

2.5

72

0.08

It was our constant endeavor to so anneal as to exclude all errors due 

to superficial oxidation and carburation. Whether this was accomplished remains to be seen. In Fig. 7 the temperature at which the rod 

was annealed is given as abscissa, the corresponding density as ordinate.

(100)
BAtttrs AND sTROUttAL.] SUDDEN COOLING 01? GLASS AND STEEL. 101

The commercial density for the respective cases is indicated by an 

attached c.

FIG. 7. Diagram showing variation of the density of steel, with temperature of annealing.

Discussion. We advert in passing to the fact that, whereas density 

increases continually on passing from, hard to soft, resistance passes 

through a pronounced minimum.

Whether we regard A§ as a function of resistance or of the temperature IP at which the rod was annealed, the relations investigated lead 

to an important inference with an immediate bearing on our present 

purposes. It appears plainly that the annealing of a rod successively from 

extreme hard to extreme soft does not exhibit the characteristics of a single 

and homogeneous phenomenon. This annealing presents two distinct 

and independent phases, which merge into each other when t° corresponds to incipient redness. The graphic representation of A0 varying 

with t° shows this transition with singular clearness. Between t°= 200 

and t°= 500 all the loci pass through two consecutive circumflexures in 

such a way as to change the general and pretty uniform contours of 

concavity downwards into convexity downwards for the interval in 

question. The division of the complete phenomenon into two parts being thus suggested, we find on further inspection that the variations of 

the electrical constants of temper subside almost completely within the 

first of these parts (annealing between 0° and 350°) ; whereas in the 

second part (annealing between 350° and 1,000°) they become crowded 

and complex. It follows plausibly and at once that during the first 

of the phases under consideration we encounter the subsidence of a 

mechanical, strain. > This inference gains much in weight when we find 

that this strain vanishes, in the way peculiar to phenomena of viscosity, at a slowly decreasing rate, through infinite time.1 In the sec1 In other words, the temper strain vanishes just like the simple " drawn" strains 

imparted hy the wire plate while the wires carrying them are each exposed to the 

prolonged action of temperature.^-Bull. No. 14, U. S. Geol. Surv., p. 93.
102 WASHINGTON LABORATORY. [BULL. 42.

ond phase, mechanical and chemical occurrences are superimposed and 

the above results do not enable us to disentangle them.

The final important deduction from the data is this, that during the 

first phase, in which the larger values of resistance are from two to three 

times the smaller values, the variation of density is slight. In the second phase we encounter large variations of density associated with 

small variations of resistance.

These curious relations characterize the phenomenon as a whole. We 

shall interpret them partially at least below.

DENSITY AND STRAINS IN TEMPERED GLASS.

Experimental results. This result substantiates the evidence in favor 

of the existence of strain in hard steel adduced in our earlier papers. 1 

Beyond this it shows almost conclusively that the density effect of the 

annealing of hard steel is out of all proportion and symmetry with the 

strain effect and the corresponding electrical effect. We were desirous, 

therefore, of studying the temper strain in substances other than steel 

and free from carbon. Long ago glass had suggested itself to us for 

this purpose.2 We communicate in the following Table II the density 

effect produced by successive annealing of ordinary Prince Rupert drops. 

Twelve of these were in hand. Three were broken to test the strain, the 

remainder examined. All the drops contained included bubbles, one 

or more, often 0.2cra to 0.3cm in diameter and distributed irregularly. 

Usually a few large bubbles predominated. The drops moreover showed 

a purple coloration, which disappeared after annealing at incipient redness.3 To anneal the drops at different temperatures we inclosed them 

in a test tube, cushioned upbn and surrounded by carded asbestus. The 

end of the tube was submerged sufficiently to cover the Prince Rupert 

drops in boiling camphor, mercury, sulphur, &c., as given in the table. 

To anneal at red heat, the drops were suspended in little baskets of 

platinum foil, in the center of large thick clay crucibles, and then heated 

. to the desired temperature in an assay furnace. Under all circumstances but one care was taken, to cool the drops slowly. Table5 II contains under " temper" the temperature and time of annealing, not including the time of cooling, however. The column m gives'the weight 

of each drop in grammes. Yariations ofm are due to accidental breakage 

of the frail stems of the drops. Where no such breakage occurs m is 

constant. At is the density of the drops at t°; J0 ? finally, is the density 

of the drops at.0° 0., under the conditions given. Each AQ is the mean 

of two independent determinations and is correct to within One or two 

units of the third place.

1 Bull. No. 14, U. S. Geol. Snrv., pp. 88-103.

2 Wied. Ann., VII, p. 406, 1879.

3 The color of the drops is amethystine. Mr. R. B. Riggs, of the U. S. Geological 

Survey, kiudly analyzed the glass and found manganese.

(102)
iuuus Aisi) STKOUHAL.] SUDDEN COOLING OF GLASS AND STEEL. 103

TABLE II. Temper, tueight, and density of quenched glass (Prince Rupert drops) successively

annealed.

No 

1

2

3 

4 

5

6

.7 

8

Temper.

Annealed, 360°, 30m (mercury) .. £

Quenched...................... <

Annealed, 360°, 30m (mercury) . . j 

Annealed, 600°, 10 . __ . . ...... 2

Quenched ...................... j

Annealed, 200°, 15m (paraffine) . . . 

Annealed, 360°, 30m . ............ £

Quenched...................... }

Annealed, 360a,30m . ............ $

Quenched.... .................. 5

Annealed, 200°, lh 30 (camphor) . 

Annealed, 300°, lh (mercury) . . . J

Annealed, 450°, 30 (sulphur) - - i

Annealed, red heat ............ 5

Quenched ...................... j

Annealed, 200°, lh 30m (camphor) . 

Annealed, 360°, lh (mercury) . . . j

Annealed, 450°, 30m (sulphur).. \

Annealed, red heat ............ <

Quenched ...... ................|

Quenched. ..................... <

m

1. 3500 

1. 3501 

1. 3500 

1. 3500

1. 3497 

1. 3496

1. 3470 

1. 3470 

1. 3311 

1. 3312 

1. 3200 

1. 3201 

1. 3201 

1. 3200

1. 3191 

1. 3190

1. 3172 

1. 4590 

1. 4590 

1. 4591 

1. 4590 

1. 4590 

1. 3305 

1. 3304 

1. 3305 

1. 3292 

1. 3292 

1. 3009 

1. 3010 

1. 3009 

1. 3010 

1. 3010 

1. 3012 

1. 3012 

1. 2983 

1. 2982 

1. 2983 

1..4409 

1. 4408 

1.4409 

1. 4409 

1.4409 

1. 4412 

1.4412 

1. 4410 

1.4408 

1.4407. 

1. 4795 

1. 4795 

1. 0024 

1. 0026

t

0

17.9 

17.0 

15.6 

15.8

14.8 

15.3

18.0 

18.0 

18.4 

18.2 

17.5 

16.8 

15.7 

15.8

15.1 

15.5

18.5 

15.9 

16.0 

15.9 

16.5 

1C. 9 

16.0 

16.0 

16.3 

16.7 

17.0 

16.8 

16.8 

15.9 

16.5 

16.8 

17.3 

17.4 

16.2 

17.5 

17.8 

16.8 

16.9 

16.0 

16.7 

16.9 

17.1 

17.4 

16.4 

17.7 

17.9 

16.2 

17.6 

16.3 

17.6

At

2. 4336 

2. 4333 

2. 4388 

2. 4394

2. 4894 

2. 4890

2. 4901 

2. 4896 

2. 4872 

2.4904 

2.4354 

2. 4354 

2. 4392 

2. 4404

2. 4898 

2. 4891

2. 4901 

2.4364 

2. 4364 

2. 4354 

2. 4403 

2. 4399 

2. 4345 

2. 4348 

2. 4341 

2. 4369 

2. 4378 

2. 4333 

2. 4344 

2. 4349 

2. 4390 

2. 4394 

2. 4441 

2. 4431 

2. 4521 

2. 4906 

2. 4900 

2. 4312 

2. 4315 

2. 4323 

2. 4370 

2. 4374 

2. 4410 

2. 4414 

2.4524 

2. 4878 

2.4885 

2. 4385 

2. 4385 

2. 4389 

2.4381

Mean 

Ao

2. 4345

2.4401

2. 4901

2. 4910

2. 4883 

2. 4915 

2.4364

2. 4408

2. 4903

2. 4912 

2. 4374

2. 4364 

2. 4411

2.4356

2. 4351 

2. 4383

2. 4349

2. 4359 

2. 4402

2. 4446

2.4531 

2. 4914

2. 4323

2. 4333 

2. 4382

2. 4422

2. 4534 

2.4893

2. 4395

2. 4395

Remarks.

| Bubbles ; color.

| . Do.

{

Bubbles and color vanish. 

Slow cooling ; form of drop 

not changed.

? Slow cooling.

Cooled in air. 

Cooled slowly.

] Bubbles; color.

| Do.

f Bubbles and color vanish ; 

< slow cooling ; form of drop 

I not changed. 

Slow cooling.

f Bubbles; color. 

Do. 

j Do.

| Bubbles; color. 

Do. 

| Do.

| Do. 

Do. 

| Do.

| Do.

Dolor vanishes; slow cooling. 

> Bubbles vanish ; form of drop 

} partially changed.

| Bubbles; color. 

Do. 

£ Do.

£ Do.

Color vanishes slow cooling. 

(Bubbles gone; form of drop partially changed ; slow cooling.

| Bubbles; color. 

^ Do.

(103)
164 WASHINGTON LABORATORY. ' [BULL. 42. 

TABLE II. Temper, iveight, and density of quenched glass, $c. Continued.

No.

9

Temper.

Annealed, 360°, 30m (mercury) . . < 

Annealed, 360°, 3h (mercury) . .. < 

Annealed, 450°, lh (sulphur) . . . < 

Annealed, 450°, 4h (sulphur) . . . , j

Annealed. 360°, 30m (mercury).. £ 

Annealed, 300°, 3h . ............. J

Annealed, 450°, I".... ...... ....£

Ann Gelled 450^ 4^ <

m

1. 0025 

1. 0025 

1. 0023 

1. 0023 

1. 0023 

1.0023 

1. 0023 

1. 0023

0. 9982

1. 2758 

1. 2760 

1. 2746 

1. 2744 

1. 2745 

1. 2745 

1. 2745 

1. 2745 

1. 2727 

1. 2727

1. 1592

t

o 

17.4 

17.5 

16.8 

17.3 

18.2 

18.2 

16.5 

16.8

18.5

17.0 

17.6 

17.4 

17.5 

17.0 

17.4 

18.2 

18.3 

16.7 

16.8

18.4

At

2. 4434 

2. 4434 

2. 4474 

2. 4471 

2. 4515 

2.4515 

2. 4579 

2. 4574

2. 4890

2. 4363 

2. 4346 

2. 4410 

2.4416 

2. 4425 

2. 4427 

2. 4461 

2.4461 

2. 4499 

2. 4501

2. 4918

Mean 

Ao

2.4444

2.4482

2. 4526

2. 4586

2. 4901 

2. 4365

2. 4423

2. 4430

2. 4472

2. 4510

2. 4929

Remarks.

£ Bubbles; color. 

} Do. 

\ Do. .

| Do.

f Bubbles and color gone; form 

< partially changed; slow 

[ cooling.

> Bubbles; color. 

| Do. 

j Do. 

| Do.

j Do.

{

Bubbles and color gone ; slow 

cooling ; form of drop partially changed.

Table III, following, is constructed to facilitate a comparison of the 

important data. The second and third columns contain the densities 

of the extreme states of temper, the original quenched, "hard," and 

the final " soft," or thoroughly annealed state. The remaining columns 

contain the increments of density due to quenching, relative to the 

density of the soft state, the relative increments, in other words, which 

are retained at the divers temperatures given.

TABLE III. Summary allowing density of Prince Rupert drops, quenched and annealed.

No.

1. ................ .......

2

3........................ 

4........................

0. .......................

t

8. .......................

9........................

"Hard." 

<V

2. 4345 

2. 4364 

2. 4374 

2.4356 

2. 4349 

2. 4323 

2. 4395

2. 4395 

2.4365

"Soft." 

AO2. 4915 

2. 4912

2. 4914 

2. 4893

2. 4901 

2. 4929

Density increment relative to "soft," when annealed at 

20°.

-Or-0229 

-0. 0222 

-0. 0216 

-0. 0223 

-0. 0227 

-0. 0229 

-0.0207

-0. 0203 

-0. 0227

200°.

-0. 0220 

-0. 0225 

-0. 0223 

-0. 0225

......} 

,:...}

360°.

-0. 0207

0. 0202

-0. 0201 

-0.0212 

-0. 0206 

-0. 0205

-0.0184 

-0. 0168 

-0.0203 

-0.0198

450°.

-0. 0188 

-0. 0189

-0. 0150 

-0. 0127 

-0. 0184 

-0. 0168

(550°.)

-0. 0154 

-0. 0144

(050°.)

-O.OOOC 

-0. 0004

Red heat.

' -0.0002 

-0.0000

-0.0001 

+0. 0007

-f 0. 0004

-0.0007

(104)
flAStis AXD WROUHAL.J SUDDEN COOLING OF GLA^S AND STEEL. 105

Discussion. The salient features of these data are obvious from an 

inspection of Table III. The density effect of quenching is decidedly 

negative, the increase of specific volume is exceptionally large. Moreover, the nine1 Prince Eupert drops examined exhibit nearly the same 

initial density and nearly the same final density. The approximate 

equality of the values J0 for the soft state is easily explained. It 

indicates that in proportion as we bring the strain to vanish we reach 

the normal density of the glass. It is not so easy to account for the 

observation that the density of the Prince Rupert drops shows almost 

the same degree of equality in the hard (quenched) state. Indeed," if 

we take the fact into consideration that the drops invariably contain 

bubbles distributed irregularly, and without apparent relation as regards 

size and number, the difficulties of explanation are increased. In other 

words, it is an exceedingly striking and important result that the volume increase due to quenching is quite as much the same for all drops 

as is at all possible for the case of so complicated an operation. We 

are thus led to this inference: Inasmuch as bubbles are present in 

like total volume in each of the drops, their presence cannot be a 

circumstance of mere accident; they must be regarded as a normal 

effect, or, better, a necessary result of the operation of quenching applied to glass j they must in some very intimate way be connected with 

the strain which the glass globules have experienced in virtue of sudden cooling.

Retaining this very reasonable surmise in mind, we proceed to a more 

minute inspection of the effect of annealing the hard Prince Rupert 

drops. We obtain results very similar to those investigated above for 

steel. The density effect of annealing is decidedly positive, and is 

greater as temperature and time of exposure are increased. Again, we 

readily divide the physical effect of annealing into two parts or phases. 

The first of these corresponds to the annealing temperatures 0° to 500°, 

the other to higher temperatures. The range of temperatures corresponding to the first phase is therefore larger for glass than for steel; 

and if we compare Tables I and II it appears obviously that for like 

density effects the annealing temperatures must be chosen higher in 

the former case (glass) than in the latter. But the change of density 

encountered in both instances is small j and yet, in spite of the small 

density effect during the inferior stage of annealing, by far the greater 

intensity of strain vanishes. The drops after annealing at 200° are still 

explosive; if they be broken after having been annealed in boiling sulphur at 450° they are found to have lost all traces of the explosive properties which the originally quenched drops possessed. Professor O. N. 

Rood 2 informed us that the polarization figures could be quite wiped 

out by annealing such ordinary glass as exhibited them only as far as 

the temperature of melting zinc. We infer that at the end of the first

1 Further (incidental) examples are given in the next section, p. 115. 

2 Kesults obtained by Professor Eood during his experiments with high vacua.

(105)
106 (BULL. 41

phase of annealing we have in hand a hollow glass globule practically 

free from strain.

During the second phase of the annealing phenomenon (500° to 1000°), 

we observe a very pronounced change of the density of the Prince 

Eupert drops, corresponding to the above result for steel. But the explanation is here readily at hand; at incipient redness the inclosed 

bubbles disappear or are reduced to mere specks. The large increment 

of density in question is therefore nothing more than an expression for 

the collapse of the viscous hollow globule in virtue of atmospheric pressure. This important observation enables us to interpret all the phenomena of annealing satisfactorily. It must therefore be carefully examined.

We shall endeavor to prove that the bubbles are vacua, that they are 

not accidental inclusions of gas or aqueous vapor. The temperature 

from which glass is quenched is certainly 'less than 1500°. The temperature at which glass is sufficiently viscous to yield easily to atmospheric pressure is certainly greater than 500°. Suppose now that the 

changes of volume of the bubble were the result of thermal expansion 

of an included gas. Let v\5W and #506 be the volumes of the gaseous 

inclusion at 1500° and 500'°, respectively, under normal pressure. Let 

vh and v, be the volumes of the gas bubble for the quenched (hard) and 

annealed (soft) states. Then we deduce, a fortiori,

 < =2.3 ' (1)

V, «500

With this as a point of departure the following little digest of mean results, Table IV, has been prepared. Here m is the mean mass of all the 

drops examined ; /J A , 4,, FA, F4, their mean density and total volume for 

the hard and the soft states, respectively; v is the mean volume; r the 

equivalent mean radius of the bubbles. In the second horizontal row 

"P"fl has been diminished one-half per cent., to refer all volumes to the beginning and end of the second phase of annealing.

TABLE IV. Mean volume relations of the Prince Eupert drops and of the hypothetical.

gas bubble.

V A

CC.

0.5454

0. 5427

cc.

0. 5334

0. 5334

v at 

1500°.

cc.

0. 0120

0. 0093

500C.

cc.

0. 0052

0. 0041

rat 

1500".

c.

0.142

0.130

500°.

c.

0.107

0.099

Vh

 <2.3

-<1.3

r«

Mean m = 1.3288 g 

" Hard:" Mean A* = 2.4363 ± 0.0008 

" Soft:» Mean A. = 2.4911 ^ 0.0016

(106^
BAUDS A»D STROUHAL.] SUDDEN COOLING OF GLASS AND STEEL. 107

Inasmuch as the values v500 and r500 are inferior limits, it is clear that, 

if the bubbles were gas or vapor, they would be of the same order of 

visibility before and after annealing. In other words, if the bubbles 

were gas, casual inspection would not detect a difference of their size 

in the "hard" (quenched) and in the "soft" drops. In the experiments, 

however, the bubbles all but vanish. Hence they cannot be gas.

To obtain additional assurance on this point we ground flat faces on 

the annealed drops Nps. 1, 5, and 8, and then measured the size of the 

inclusions. We found these values :

No. 1: ». = 0.000037". 

No. 5: v,= 0.000062". 

No. 8 : «. = 0.000040 ". 

Mean: ^ = 0.000046".

From actual measurement therefore we find

-A >100 - (2) va v '

iih 

a result wholly incompatible with < 2.4, as derived above (Table IV).

It follows conclusively that the bubbles are not accidental gas inclusions and that only an insignificant part of the variations of volume produced by quenching can be referred to thermal expansion of gas.

If the gas were aqueous vapor and if dissociation were complete, 

then the upper limit of (1) would have to be increased in the ratio of 

3 : 2. This does not remove the discrepancy between (1) and (2). More-. 

over, since dissociation of water is only incipient at 1500°, and is not 

even complete at the temperature of melting platinum, the volume variation of the bubbles cannot be clue to the presence of water in the bubbles.

If, on the other hand, we endeavor to explain the bubbles as vacuities1 left by the contracting glass, we arrive at accordant and reasonable 

results. Let t be the temperature to which the homogenous glass drop 

must be heated in order that the observed mean volume of the soft 

state may be equal to the observed mean volume of the hard state. 

Then, since volume increases at an accelerated rate with temperature,

where a is the ordinary coefficient of linear expansion of glass. By inserting the values of Table III into (3) we derive

K9QOQ. -

In* other words, the quenched globule has retained the volume which 

the hot glass possessed at a temperature certainly smaller than 900°. 

This result taken together with the other is conclusive (see p. .112).

1 Very analogous to Torricellian vacua. 

(107)
108 WASHINGTON LABORATORY. [BULL. 42.

The general result of our investigation on the process of sudden cooling, therefore, points out the fundamental importance of. a rigid shell. 

As the material (glass or steel) cools, contraction as a whole takes 

place not centripetally but centrifugally, i. e., not towards the center 

of the figure, but away from it. So long as the interior remains liquid or 

viscous, the result is simple separation, commencing at points where 

minute air bubbles may pre-exist,1 rather than at points of the continuity of glass. The final result is a vacuum bubble such as we have 

observed. In proportion as the interior becomes rigid the temper strain 

appears. Should the glass hold gases in solution, they would tend to 

escape into the vacua in question., There is probably another .reason 

why in most instances the bubbles cannot be brought completely to vanish. Annealing reverses the whole phenomenon. The small changes of 

density observed in the first phase may be easily accounted for: it is 

probable that during these, stages of annealing the rearrangement of 

molecules and disappearance of strain are. accompanied by expansion 

inward toward the vacua. Hence the incommensurately small variation of mean density which accompanies the great optical effects (glass) 

and the great electrical effects (steel). 2 During the second stage of 

annealing, again, the density effect is incommensurately large; for glass 

it is the expression of a mere collapse, due to the atmospheric pressure. At all events the density effect (error) due to bubbles quite 

swallows up the density effect due to strain. Hence to represent the 

true relation of density and resistance or of density and annealing 

temperature in case of steel, it may be necessary to lower the part of 

the curves corresponding to the second phase of annealing by amounts 

equivalent to the bubble or fissure discrepancy, or else for like reasons 

to raise the parts of the curves corresponding to the first phase. If 

this be done, the circumflexures become less pronounced or disappear, 

and the points for the commercial soft state are more easily referred 

to the curves to which they belong. If, therefore, allowance be made 

for the distortion due to internal sensible pores, the relations become 

more uniform.

It is interesting to observe that glass retains the volume expansion 

corresponding to a temperature somewhat below 900°, whereas steel 

retains the volume expansion of a temperature below 400°. Similarly, 

the strain in steel is very perceptibly affected by annealing temperatures 

as low as 50°, whereas for glass the perceptible annealing effects are 

only incipient even at 200°. The amount of strain retained is, cseteris 

paribus, not merely a function of the viscosity of the material subjected to

prince Eupertdrop No. 1, heated intensely in a blast lamp aud cooled in air, shows 

a decrement of density. This is due to the rapid cooling; for-when this drop is 

heated and cooled in the crucible, density is again incremented. The experiment 

shows the tendency of glass to retain strains. During the heating to 1000° no expansion of the very small bubbles was observable.

2 The electrical and optical criteria may be considered equally sensitive.

(108)
BABUS AND STBOUHAL.J SUDDEN COOLING OF GLASS AND STEEL. 109

quenching ; it must depend also on the heat conductivity of this substance. For instance, if like figures of glass and of steel be quenched 

alike, then at the same time and depth the thermal gradient would be 

much steeper in the case of glass than in the case of steel. Hence, cseteris 

paribus, during quenching a rigid shell is possible in the case of glass for 

higher temperatures of the core than in the case of steel. The sudden 

contraction of the shell (pressure) has a marked effect on the melting 

point or degree of fluidity of the core. But it is best to waive this observation here, for the want of data to interpret it.

We have finally to consider the bearing of the results of this paper on 

the structure of steel. The detailed similarity observed in the annealing of glass and of steel suggests the inference that the interior of hard 

steel may be sensibly fissured. Under all circumstances the diagrammatic structure of dense shell and rare core would be inaccurate to the 

extent in which these fissures are irregularly distributed. Hence the 

difficulty of developing the .true character of the dependence of the 

density (tf) at any point upon the distance of this point below the surface. We are able to account in part for the quasi-harmonic relations 

obtained both by Dr. Fromme1 and by ourselves.2 While the consecutive shells are being removed by solution, periodic fluctuation of d must 

result whenever fissures are invaded. If, furthermore, we take into 

consideration that the density effect of even gr.eat intensities of temper 

strain is small, it appears that the true nature of the strained structure 

of tempered steel may be beyond the discernment of the density method 

of investigation altogether. The gross variation of density along the

radius is a carburation phenomenon.

a

POLARISCOPIC OBSERVATIONS.

In this place we desire to substantiate the earlier inferences of this 

section and to give sharper expression to them. We therefore repeat 

Professor Eood's experiments on the polariscopic effect of continuous 

annealing of cooled glass at low temperatures. Our object is merely to 

detect variations in the polarization figure produced by annealing or, 

later in our work, by the removal of superficial shells. Hence it is sufficient to examine the drops in a given fixed position between polarizing 

plates.3 Disturbances due to diffuse refraction are satisfactorily eliminable by submerging the Prince Eupert drop in glycerine, the refractive 

power of which is nearly that of the glass. The demarkation is then 

distinct and the colors clear, so that the figures can easily be drawn. 

The necessity of grinding special faces or plates is thus fortunately obviated, for in case of the quenched drop such operations are not 

feasible.

'Wied. Ann., VIII, p. 356,1879. - 

3 Bull. No. 35, U. S. Geol., Surv. p. 36.

3 We are indebted to Professor Hitchcock for the use of a simple but efficient reflecting polariscope, .formerly the property of Professor Joseph. Henry.
110 WASHINGTON LABORATORY. [BULL. 42.

In the case of simple annealing, variations of the polarization figure 

are due to a diminution of what we may loosely call the birefractive 

power of the Prince Eupert drop. In the case of removal of shells, as 

described in the next section, variations of figure result from diminution of thickness, possibly associated with diminution of birefractive 

power. The solution of the drop in hydrofluoric acid does not materially interfere with its transparency. The optic observations may therefore be continued indefinitely»

Our polariscopic experiments were made with the Prince Eupert 

drops Nos. 1, 2, 4, 6, and Nos,, 3, 5, .7, 8, 9. The first four of these were 

simply annealed, the remainder1 examined after consecutive removals 

of shells. It is expedient to describe only the experiments with annealed drops in this section. These experiments are so striking and so 

easily repeated, on the one hand, and so difficult to reproduce accurately 

iu a drawing, on the other, that the following very careful free hand 

sketches of the main features of the figures are here inserted, principally 

for purposes of record. The cuts represent Prince Eupert drops Nos. 1, 

2, 4, and 6 in fixed position between nicols.

On annealing as far as T = 200°, variations of figure are not certainly perceptible. After very long annealing at this temperature (200°) 

a faint influence appears, but is restricted to changes of color. It is 

particularly to be observed that the position and contours of the origi^ 

nal polarization figure show a very obvious relation to the position of 

the included bubbles (black spots in the figure). This was the invariable result for all the Prince Eupert drops examined. It is in accord 

with our inference of <k centrifugal" contraction,2 discussed above.* At 

200°, therefore, change of strain in glass is incipient. The Prince Eupert drop, if broken, is still explosive, though perceptibly less so than 

the original drop.

After one hour of annealing in boiling mercury (360°) the changes of 

the polarization figure are obvious. The whole appearance is more diffuse, the colors bolder and broader, and the deinarkation less distinct 

and delicate. These striking observations can only partially be reproduced in a figure. We have encountered very marked diminution of 

birefractive power. After seven hours of annealing in boiling mercury 

the evidences of diminished birefractive power have visibly increased. 

The figures as a whole are simpler, the coloration more gross.

Finally, after annealing in boiling sulphur (450^), the polarization 

figure has wholly vanished; we have in hand a hollow glass globule, free 

from a3olotropic strain. We show on page 121 that the substance of the 

Prince Eupert drop is under a strain of dilatation. It is necessary to 

bear in mind that the isotropic part of this strain is not demonstrable 

by optic means. The drop annealed at 450°, however, has -wholly lost 

its explosive character.

1 § II, p. 116. 2 § I, p. 108.
BAUUS ANP STROUHAL..I SUDDEN COOLING OF GLASS AND STEEL. Ill

FIG. 8. Polarization figures of Prince Rupert drops.

(Ill)
112 WASHINGTON LABORATORY. LBULL.42.

Here we encounter the first important analogy between the optical 

behavior of quenched glass and the electrical behavior of quenched 

steel. We shall show that this parallelism extends even into details. 

Change of strain in glass is incipient at 200°, in steel at 50°. Change 

of seolotropic strain in glass is complete at a temperature certainly 

greater than 350° and less than 450°. The corresponding superior limit 

for steel cannot be so well defined. In both cases the essential dependence of the result to be reached on the temperature and the time of 

annealing (asymptotic relations) is the marked feature of the phenomenon.

§ II. THE STRAIN IMPARTED BY SUDDEN COOLING, AND ITS STRUCTURAL RELATIONS.

In the last section we compared the strains experienced by glass and 

by steel on sudden cooling by aid of the density variations observed on 

annealing the bodies carrying strain as a whole. Our purpose in this section is to investigate the density relations of consecutive similar shells 

of the Prince Eupert drop and the optical character of the successive 

cores. Availing ourselves of all the evidence adduced in our investigation at its present stage, we endeavor again to show that the optical 

effect of the temper strain in glass may be regarded as the precise arialogon of the electrical effect of the temper strain in steel.

CERTAIN GENERAL PROPERTIES OF THE PRINCE RUPERT DROP.

It is well known that mere breakage of the tail of a Prince Eupert drop 

is sufficient to shatter it; the splinters fly apart with explosive violence. It is not so well known that the same drop may be dissolved 

in hydrofluoric acid to a mere spicule without exploding. 1 This peculiar behavior calls to mind certain properties of nitroglycerine, inasmuch as this substance may be burned off quietly in a wick but explodes on percussion. It is in keeping, moreover, with Dr. F. A. Gooch's 

ingenious suggestion that in the quenched globule we may possibly encounter a polymerization of the molecular structure of the annealed 

globule. But the fact that the strain is of an ordinary mechanical kind 

is proved by the observations of Table V, in which the behavior of Prince 

Eupert drops from which different thicknesses of shell have been removed by solution is described. In the table, "diameter" refers to the 

mean transverse thickness of the drops ; # and ^, to the thickness and 

the mass, respectively, of the dissolved shells. After removing a sufficient depth of shell, the residual explosive properties were tested 

either by crushing the reduced drop longitudinally in a vice or by 

striking in the same direction with a hammer.

1 De Luynes appears to have been the first to dissolve the drop in HF (C. R. LXXVI, 

p. 346,1873). He also discusses elaborately the effects produced by cutting glass with 

emery (0. R. LXXXI, 341,1875). Some earlier work on the vacuum bubble js du§ to 

Reusch (Phil. Mag. (4), XXXIV, p. 166, 1867).

0-12)
BARUB AND sTuouHAL.] SUDDEN COOLING. OF GLASS AND STEEL. 

TABLE V. Explosive qualities of Prince Rupert drops.

113

No.

1?

10

11

13

3

5

7

8

Minutes 

in H. F.

0

5

0

10

0

14

0 

30

0

0

0

0

Diameter.

cm. 

0.848

0.835

0.796

0.766

0.795

0.760

0.774 

0. 712

0.795 

0.688

0.825 

0.720

0.763 

0.539

0.791 

0.557

d

cm. 

0.006

0.015

0.017

0.031

0.054

0.053

O.U2

0.117

P

9-

0.291

0.493

0.491

0.722

0. 752

Kemarks.

^Shattered on being split longitudinally. Fragments more

lla not shattered on splitting. Conchoidal fracture.

>I» not shattered on splitting. Conchoidal fracture.

>Is not shattered on splitting. Conchoidal fracture.

>Is not shattered on splitting. Conchoidal fracture.

The table shows that the explosive tendency of the Prince Eupert 

drop becomes rapidly less pronounced as the thickness of removed shell 

increases, that this tendency is very perceptibly impaired by the removal of less than ^mm of shell, and that it vanishes almost wholly 

after the removal of £mm of shell. If the radius of the drop be diminished about 0.03cm the particles of the fractured globule frequently 

cohere, and the original structure may then be inferred from the general direction and distribution of the fissures. The arrangement of 

the individual fragments is quite characteristic: they are found to be 

flat, irregular conoids, with their apices toward the line of symmetry 

of the drop, their bases in its surface an arrangement something 

like the eye of an insect, or even more like the fruit cone of a spruce 

tree. In other words, the radial structure of the fissured Prince Eupert 

drop is very distinctly marked.1 This proves that the original (unbroken) drop must have possessed a box-within-box structure ; that, if 

the bubbles were symmetrically disposed, particles similarly. situated 

with reference to the line of symmetry would be in like states of strain. 

But the law according to which matter is distributed from circumference to axis cannot be inferred, since the stated phenomena follow 

equally well both for surface dilatation and for surface compression.

All the Prince Eupert drops examined were found to scratch ordinary glass with facility; but, on removing the strain from the drops by 

annealing them at white heat and slowly cooling them, their hardness

'This structure is frequently visible in fragments of large tempered steel projectiles. 

I have found glass rods which on sudden heating break up into flat fragments symmetrically disposed around the axis of the rod or again into symmetric conoidal shells 

(see note on researches of De Luynes, on preceding page).

(113) 

Bull. 42 8
114 WASHINGTON- LABORATORY. [HUM.42.

did not observably change. The hard quality was therefore a property 

of the glass itself and was not imparted by mechanical treatment. Indeed, on rubbing together a quenched and an annealed Prince Rupert 

drop no difference of hardness could be discerned.

GENERAL STRUCTURAL EFFECTS PRODUCED BY SUDDEN COOLING.

In Bulletin 35 we communicated a series of results on the resistance of 

consecutive conaxial layers of steel rods.

We there showed that it is difficult to arrive at accurate values for 

specific resistance in these measurements, for we encounter very small 

values of total resistance at the inception of the experiments and 

small and irregular values of sectional area at the close. Inasmuch as 

sections are necessarily measured too large, the values for specific resistance, S0 , are too large, and the error increases rapidly as we pass 

from greater to smaller diameters. The mean error of S0 is certainly 

several per cent., and hence the resistances of elementary shells calculated from, these data are only approximations. Nevertheless our results are important; they prove that in the case of hard rods less 

than 0.6C1U thick the values of resistance taken from circumference 

to axis along any radius do not perceptibly diminish. It was this 

curious result, apparently adverse to the hypothesis of strain, which 

induced us to examine the corresponding behavior of quenched glass.

The diameters, 2 p, of Prince Rupert drops Nos. 3, 5, were successively reduced1 as follows:

.2/0 = 0.79 0.75 0.72 0.09 0.62 0.56 cm., '' 

and 2p = 0.82 0.79 0.75 0.72 0.65 0.59 cm.

The polarization figures-drawn after each of these reductions are 

subjoined.

The figures of each drop retained a uniform character throughout 

and showed no further loss of delicacy of demarkation and of colors 

than could be referred to diminished thickness. Unfortunately it is 

not easily possible to discriminate between the effect of decrement of 

diameter and the possibly concomitant effect of lessened birefractive 

power. Hence the experiments fail to indicate whether the removal of 

consecutive shells by solution is accompanied by changes of strain 

(shrinkage). If the fragments of a shattered drop, submerged in 

glycerine, be examined under the microscope between crossed nicols, 

the presence of strain in the individual splinters is quite clearly apparent. It is well to note that marked polariscopic evidence of strain remains long after the explosive properties of the Prince Rupert drops 

have disappeared. We infer that the electrical behavior (resistance) of 

the successive cores of a hard steel cylinder is not unexemplified by 

the optical behavior of successive cores of a Prince Rupert drop j though

'We desisted from further reduction of diameter in order not to enter the bubbles,

(114)
BABUS AND SQUEAL.] SUDDEN COOLING OF GLASS AND STEEL. 115

it is difficult to say whether the behavior of the partial bodies in either 

case (partial strains) is at all comparable with the behavior of the 

bodies as a whole (temper strain).

FIG. 9. Polarization figures of successive cores of Prince Rupert drops.

In this place it is well to advert to certain important data of Table IX. 

Having removed two shells (total thickness, -#i+#2 = 0. 04 cm ) from 

each of the Prince Eupert drops Nos. 10 and 11, the core densities were 

found to be 2.4166 and 2.4147, respectively. We then annealed them 

in sulphur (450°), and found for the densities of the annealed cores 

2.42G3 and 2.4261, respectively. This increment is quite as large as is 

observed when the drops are annealed as a whole. 1 Hence we fail to appreciate any diminution of strain due to solution. Moreover, we prove 

conclusively that the increment of density which is observed on annealing at the said temperature (450°) is a true increment of the density of 

the substance of the Prince Eupert drop; that is, not a partial collapse 

of the drop in virtue of atmospheric pressure. In other words, the 

observed after action is inherent in the glass itself, a"s we pointed out 

elsewhere.2

DISTRIBUTION OF DENSITY IN PRINCE RUPERT DROPS.

Results. Availing ourselves of the property of the Prince Eupert 

drop to dissolve quietly in hydrofluoric acid, we arrived at the following results (Tables VI to X) for the variations of density along transverse radii of the drops. In these tables ".diameter" denotes the mean

1 $ I, p. 104. I, p. 103,

(115)
116 WASHINGTON LABORATORY. [BULL. 42.

transverse thickness of the successive cores; M and At show their mass 

and their density at the temperature t ; zJ0> their mean density at 0°C. 

Furthermore, //., #, tf, E, denote the mass, thickness, density, and mean 

radius, respectively, of the consecutive shells. If the ni}l core be left 

after the removal of n shells, then the suffixes to the number of the drop 

in the first column give the history of the drop succinctly. Nearly all 

the measurements are made independently in duplicate. J0 may be 

relied upon to within two units of the third place; #, to one unit of the 

second place. In no case was solution carried so far as to invade the 

main bubbles of the drops; the drops were chosen as nearly as possible 

free from small bubbles. The fusions were made in platinum baskets 

suspended in thick closed clay crucibles. This insured very slow cooling.

TABLE VI. Structure of Prince Rupert drops quenched.

Number.

3o .....................

32....................

50 . ...................

5i ....................

52....................

5

_

Diameter.

cm. 

f 0. 791

i 0. 800

f 0. 753

1 0. 756 

c 0. 730

i 0. 720 

c 0. 698

i 0. 677 

t 0. 809

I 0. 840

c 0. 762

( 0. 810 

c 0. 779

i 0.725

c 0.703

\ 0. 738

M

grin. 

1. 2577

1. 2576

1. 0375

1. 0374 

0. 8894

0. 8893 

0. 7651

0. 7650 

1. 3002

1. 3000

1. 0924

1. 0923 

0. 9317

0.9318 

0. 8090

0. 8090

A;

2.435

2.434

2.425

2. 426 

2.419

2.421 

2.411

2.411 

2.439

2.439

2.435

2.434 

2.428'

2.428 

2.418

2.418

t

°C. 

15.5

16.0

16.1

16.3 

16.7

16.8 

17.0

17.3 

15.6

15.8.

16.3

16.5 

16.5

16.6 

17.1

17.4

Mean 

AO

2. 4355

2. 4266

2.4210

2. 4120

2. 4400

2. 4347

2. 4282

'2.4181

........

f*

grm.

0. 2202

0. 2202 

0. 1481

0. 1481 

0. 1243

0. 1243

0. 2078

0. 2077 

0. 1607

0.1605 

0. 1227

0. 1228

iJ

cm.

0.020

0.015

0.019

........

0.020

0.017

0.016

........

6

2.483

2.473 

2.461

2.461 

2.474

2.483

2.465

2.472 

2.477

2.470 

2.495

2.498

Mean 

&

2.478

2.461

2.479

........

2.469

2.473

2.496

........

R

cm.

0.387

0.370

0.353

......

0.402

0.384

0.368

. .

TABLE VII. Structure of Prince Rupert drops quenched.

Number.

7o. ........... .......

72....................

73....................

4 

Diameter.

cm. 

c 0. 766

1 0. 760

( 0. 750

( 0. 743 

( 0. 736

t 0. 722 

r 0.718

i 0. 706 

r n. 685

' 0. 672

M

grm. 

1.0897

1. 0897

1. 0035

1. 0036 

0. 9254

0. 9254 

0. 8499

0. 8500 

0.7363

0. 7364

*

2.437

2.438

2.434

2.433 

2.431

2.431 

2.428

2.428 

2. 420'

2.419

t

17.3

18. 1

18.3

18.8 

18.6

18.7 

18.3

18.9 

19.2

20.0

Mean 

Ao

2. 4386

2. 4346

2. 4322

2. 4288

2. 4209

'

grm.

0. 0862

0. 0861 

0. 0781

0. 0782 

0. 0755

0. 0754 

0. 1136

0. 1136

 

cm.

0.008

0.008

0.008

0.017

........

 2. 476

2.494 

2.468

2. 455 

2.468

2.473 

2.480

2.484

Mean 

&

2.485

2.462

2.470

2.482

R

cm.

0.377

0.368

0.360

0.347

(116)
juftufi AND stRduHAL'.] SUDDEN COOLM OF GLASS AND STEEL. H7 

TABLE VII. Structure of Prince R-upert drops quenched Continued.

Number.

7^:..... ..............

7e ....................

77....................

80....................

81 ....................

8t ...................

84....................

86....................

So....................

87...................

9o .....................

9,

92 ....................

93 . ............ ....

Q*

96 ....................

96.... .............

9,

Diameter.

cm. 

f 0. 647

1 0. 635 

f 0. 610

1 0. 597 

, 0. 534

\ 0. 544 

, 0. 781

I 0. 800

< 0. 766

\ 0. 783 

/ 0. 765

\ 0. 745 

r 0. 745

( 0. 730

e 0.713

\ 0. 696

f 0. 675

\ 0. 659 

c 0. 623

< 0. 636 

< 0. 565

I 0. 550

r 0. 761

( 0. 757

f 0. 746

( 0. 742

c 0. 720

{ 0. 726

r 0. 711

< 0. 703 

f 0. 683

I 0. 667 

c 0. 628

\ 0. 644 

j 0. 613

* 0. 585 

r 0. 548

> 0. 524

M

grm. 

0. 6148

0. 6148 

0. 5136

0. 5136 

0. 3672

0. 3672 

1. 1422

1. 1422

1. 0567

1. 0567 

0. 9739

0. 9739 

0. 9024

0. 9024 

0. 7741 

0. 7741

0. 6567

'0.6567 

0. 5459

0.5460 

0. 3901

0. 3901 

1.0518

1.0517

0. 9638

0. 9638

0. 8689

0. 8689

0. 7981

0. 7981 

0. 6932 .

0. 6931 . 

0. 5846

0. 5845 

0. 4867

0. 4866 

0. 3471

0. 3471

At

2.410

2.408 

2.393

2.394 

2.362

2.363 

2.439

2.438

2.436

2.436 

2.432

2.434 

2.431

2.430 

2.421

2

JO1

2.412

2.412 

2. 403

2.402 

2.373

2.373 

2. 4377

2.438

2.436

2.436

2.432

2 AQQ

?,429

2.429 

2.423

2.422 

2.415

2.415 

2.406

2.404 

2.375

2.375

t

°O. 

20.0

20.2 

19.5

20.3 

20.2

20.6 

17.5

18.0

18.4

18.6 

18.7

18.6 

18.5

19.0 

19.3

20.2

20.2 

19.7

20.2 

20.4

20.5 

17.6

17 fi

18.5

18.6

18.8

18.5

18.6

18.8 

19.5

19.6 

20.2

20.2 

19.8

20.2 

20.5

20.5

Mean 

Ao

2. 4098

2. 3950

2. 3640

2. 4396

2. 4372

2.4344

2.4317

2.4225

2.4129

2. 4042

2. 3743

2. 4390

2. 4370

2. 4338

2. 4302

2. 4238

2.4161

2.4064

2. 3765

M

grm. 

0.1215

0.1216 

0. 1012

0. 1012 

0. 1464

0. 1464

0. 0855

0. 0855 

0. 0828

0. 0828 

0. 0715

0. 0715 

0. 1283

ft 19R3

0. 1174

0. 1174 

0. 1108

0. 1107 

0. 1558

0. 1559

0. 0880

0. 0879

0. 0949

O OQ40

0. 0708

0. 0708 

0. 1049

0. 1050 

0. 1086

0. 1086 

0. 0979

0. 0979 

0. 1396

0. 1395

1?

cm. 

0.018

0.019

0.032

........

0.007

0.010

O.O.C8

0.016

0.019

0.018

0. 036

. 0. 007

0.010

0.008

0.010

0.019

0.018

0.031

£

2.475

2.481 

2.497

2.480 

2.4T7

2.475

2.477

2.461 

2.477

2.465 

2.455

2.483 

2. 489

9 IRQ

2.479

2.476 

2.454

2.460 

2. 485

2.480

2. 455

2.465

2.475

2.459

2.466

2.483 

2.473

2.474 

2.4G9

2. 403 

2.458

2.473 

' 2. 488

2.481

Mean

S

2.478

2.489

.2.476

........

2. 469 i

2.471

2.469

2.489

2/478

'2. 457

2.483

........

2.460

2.467

2. 475

2.474

2.466

2.465

2.484

It

cm. 

0.329

0.311

0.285

0.391

0.382

0.373

0.361

0.343

0.324

0.297

......

0.375

0.366

0.357

0.345

0.327

0.308

0.283

The following densities were found for glass very slowly 'cooled from 

fusion:

No. 7? 87 97

M..--..................................... 0.3102 0.3424 0.2779

40 ......................................... 2.495 ' 2.498 2.501
118 WASHINGTON LABORATORY. 42.

Table VIII, constructed on the plan described for Tables VI and VII? 

contains results for the variation of density along the transverse axis of 

drops annealed in boiling sulphur at 450°. Polariscopic observation 

showed these drops to be free from strain.

TABLE VIII. Structure of Prince Rupert drops annealed at 450°.

No.

lo ....................

li ....................

lj ....................

2o. ...................

2i ....................

2i ....................

60 ............... ....

61 ....................

6S ....................

Diameter.

cm. 

r 0, 766

\ 0. 768

r 0. 708

( 0. 713 

r 0. 685

t 0. 690

r 0. 980

< 0. 884

j tf. 920

{ 0. 828 

t 0. 798

i 0. 866

f 0. 792

i 0. 797

r 0. 743

< 0. 738

r 0. 707.

1 0. 712

M

grm. 

1. 1663

1. 1662

0. 8897

0. 8897 

0. 7859

1. 8913

1.8914

1.4791

1. 4790 

1.3118

1. 2048

1. 2048

0. 9329

0. 9329

0. 8436

A e

2.439

2.433

2.424

2.423 

2.414

. 2.441

2.441

2.429

2.430 

2.422

2.446

2.446

2.434

2.434

2. 4274

t

°c.

19.0

19.0

17.0

17.4 

17.4

19.0

19.2

47.4

17.4 

17.4

19.0

19.0

17.2

17.4

17.4

Mean

Ao

2. 4398

2. 4242

2. 4147

2. 4420

2. 4303

2.4231

2. 4468

2. 4350

2. 4284

^

grin.

0. 2700

0. 2765 

0. 1038

0. 4122

0. 4124 

0. 1073

0.27.19

0. 2719

0. 0893

t>

cm.

0. 028

0.011

0.029

0.021

0.027

0.015

8

2.489

2.493 

'2. 503

2.488

2.481 

2.484

2.487

2.490

2. 504

Mean 

&

2.491

2.503

2.484

2. 484

2.488

2.504

' R

cm.

0.369

0.350

0. 451

0.426

0.384

0. 362

In Table IX, finally, we give the results for the Prince Eupert drops 

Nos. 10 and 11. The first two shells were removed from the drops while 

in the original (quenched) state. Both were then annealed for two 

hours at 450° and a further removal of shell effected. The numbers referring to the annealed state are primed. In other respects the notation 

is that of the preceding tables.

TABLE IX.. Stmcture of Prince Eupert drops.

No.

10n

lOi

102

10'*

10'3

10'4

Diameter.

cm.

r 0. 775 

1 0. 747

r 0.735 

( 0. 69D 

r 0. 733

1 0. 700

j 0.697 

1 0. 654

, 0. 656 

\ 0, 617

M

9- 

1. 2984

1. 2985

1. 0766 

1. 0767

0. 9014 

0. 9014

O QftlJ.

0. 9014

0. 7425 

0. 7425

0. 6133 

0. 6132

At

2. 4333

2. 4331

2.4260 

2. 4250

2.4147 

2. 4160

2. 4246

2. 4127 

2. 4118

2. 3958 

2. 3978

'

21.5

21.9

22.0 

22.2

21.3 

21.5 

22.0

99 9

22.0 

22.3

22.4 

21.5

Mean

Ao

2. 4346

2i 4269

2.4166 

2. 4263

2.4136

2. 3982

H

ff.

0. 2218 

0.2218

0. 1732 

0. 1733

0. 1589 

0. 3589

0. 1292 

0. 1293

'

cm.

(0. 02)

0.022

0.020

0.020

a

2.471 

2.475

2.487 

2.475

2.488 

 2.488

2.498 

2.482

R

cm.

(0. 39)

0.370

0.348

0.328

Remarks.

]

;> Quenched.

1

J

1

S Annealed at 450°, 2".

I °

(118)
ANU feTuotttAt.] StJDDEN COOLING OF GLASS AND STEEL. 

TABLE IX. Structure of Prince Eupert drops. Continued.

119

No.

11o

111 

llj

11'2

ll's

11'4

Diameter.

cm.

r 0. 730 

t 0. 707 

f 0. 690 

i 0. 670

f 0. 690

1 0. 670

f 0. 626 

1 0. 644 

r 0. 603 

< 0. 578

M

a1. 0470

1. 0457

0. 8555 

0. 8555 

0. 7173 

0. 7173

0. 7172

0. 7173

0. 5825 

0. 5825 

0. 4678 

0. 4677

At

2.4350

2'. 4337

2. 4271 

2. 4263 

2. 4138 

2. 4131

2. 4245

2. 4249

2. 4077 

2. 4067 

2. 3894 

2. 3917

t

-G.

21.7

22.0 

22.2 

21.5 

21.6

22.0

22.0

22.1 

22.2 

22.5 

21.6

Mean 

Ao

2. 4357

2. 4281 

2. 4147

2. 4261

2. 408C 

2. 3919

J*

9-

0. 1915 

0. 1902 

0. 1382 

0. 1382

0. 1347 

0. 1348 

0. 1147 

0. 1148

&

cm.

(0. 02) 

0. 020

0.023 

0.023

S

2.473 

2.469 

2.500 

2.499

2.502 

2.508 

2.487 

2.471

R

cm.

(0. 37) 

0.350

0.329 

0.306

Remarks.

1

Quenched.

]

I Annealed at 450°, 2k.

j

Discussion. An inspection of Tables VI and VII shows at once 

that 4o, the density of consecutive cores, continually decreases. This 

is easily accounted for, since the bubble error becomes relatively large 

as the mass (M) of the Prince Eupert drop decreases.

If we construct the density of consecutive shells (<5) as a function of 

their mean radius (JR) and then compare the diagrams which obtain for 

the five Prince Eupert drops, Nos. 3, 5,7,8,9, we find that the loci have 

no salient feature in common. Possibly an increase of d as we approach 

the deeper layers may be discernible, but it is indistinct. Hence the 

true variation of d from surface to axis of a Prince Eupert drop is here 

unrecognizably obscured by errors of observation. Indeed, we shall 

find below that the probable total variation of 6 attributable to strain 

will not far exceed 0.5 per cent. The accuracy of S is certainly not 

within this figure. Again, if we compare the contours of corresponding 

. curves d ==/(J2), in Table Vfor drops free from strain, with each other and 

with the contours belonging to Tables III and IV, we encounter fluctuations of the same kind in both cases. These errors include the inaccuracies of mere measurement (the mass of the drops is unfortunately small 

and the pycnometer methods are not easily applicable), as well as such 

discrepancies as result from the unavoidable invasion of small bubbles 

during solution. ,

If, however, we compare the mean values of d for strained shells 

(Tables VI, VII, and IX) with the mean values of d for shells free from 

strain (Tables VII and IX), we find the latter values (unstrained glass) 

always in excess of the former. In other words, although our results 

are insufficiently sharp to enable us to describe the exact nature of the 

temper strain in glass, they do permit us to classify it as a strain of 

dilatation, so far as we have observed, throughout the substance of the 

drop. This observation is of importance, and we have therefore drawn

(119)
120 WASHINGTON LABORATORY. [BULL. 42.

up the following general tabular comparison, to supplement the special 

and direct comparison given in Table IX.

In Table X A, is the density of the glass itself after thorough annealing at red heat, as found in our earlier section, page 117, the datum being 

the mean value for six drops j A', is the density of the glass after fusion 

in a platinum basket and very slow cooling. The additional increment 

of the density of the glass thus produced is to be noted. dh and d' denote the densities of shells strained (quenched) and unstrained (annealed 

at 450°), respectively. The sixth column contains the relative value of 

decrement of density for each drop; th'e second column, finally, the 

number of shells whose average d is the datum given.

TABLE X. Density relations of tempered glass relative to soft glass (mean results for

shells').

A, = 2.491

Prince Rupert drop 

No. -

3..........

5..........

7..........

8..........

9..........

10.........

lla........

1..........

2..........

6..........

Mean .....

Number 

of shells 

dissolved.

3 

3

7 

7 

7 

2+2 

2+2 

2

2 

2

(tt)

4k

2. 473 ±0.006 

2. 479 ±0.008 

2. 477 ±0.003 

2. 474 ±0.004 

2. 470 ±0.003 

2. 477 ±0.008 

2. 485 ±0. 029

2.470

S'-A«_ (

A8

'

2. 489 ±0.002 

2. 492 ±0.020 

2. 497 ±0.000 

2. 484 ±0.000 

2. 496 ±0.008

2.492

A's

2. 495 

2.498 

2.501

........

2.498

)

th-i'

As

0. 0076 

0. 0052 

0. 0060 

0.0072 

0. 0088 

0.0064 

0.0028

0. 0063

tt In view of the large value of probable mean error of this measurement, we thought seriously of rejecting it; but we were unable to find any error in the work, and hence the datum has been retained. 

Its effect is principally apparent in the ratio, which it depresses in a way adverse to our inferences.

To facilitate further comparison, we insert also the corresponding 

table for steel.1 Here 2 p are the diameters of the steel rods j z/ft , A^ 

AC ) their densities in the hard, the soft, and the commercial soft states, 

respectively. A1', finally, denotes the observed densities of steel at the 

end of the first phase of annealing (350°), and therefore applies for rods 

free from aeolotropic strain. The table gives us the following relative 

decrements of density: column first, the total decrement; columns 

second and third, the decrements corresponding to the first and second 

phases of annealing, respectively.

1 See Bull. No. 27, U. S. Geol. Surv., p. 46. 

(120)
AXD BTBOUHAL.] SUDftEtf COOLING OF 'GLASS AND STEEL. 

TABLE XI. Density variations of tempered steel relative to soft steel.

No.

I .........

II .........

61 to 03... . 

0. .........

2lto29....

2p

1.90

0.58

0.13 

0.23

0.08

Aft-A8

~ Ac

0. 0048

0. 0155

O.OIL71 

0. 0433

0.0150

0. 0131

Aft-A'

- Ac

0.0018

0. OOCO

0. 0068 

0. 0080

0. 0033

0. 0052

A'-A8

Ac

0. 0029

0. 0095

0. 0103 

0. 0053

0. 0116

0. 0079

Tables X and XI show that both in the caso of glass and of steel the 

mean strain effect of. sadden cooling is dilatation throughout the mass 

of the quenched material, 1 that the mean amounts of dilatation for 

glass and for steel are of like order, and that the strain in glass exceeds 

that of steel. We find, in general, that the practically measurable 

value of density is not a satisfactorily sharp datum for discerning the 

primary causes of the electrical, the optic, and the magnetic variations 

of the substance quenched. These, therefore, will have to furnish nice 

descriptions of strain and interpret what we have called elsewhere the 

individuality of magnets.

In the above paragraphs we have pursued the analogy between the 

optical behavior of tempered glass and the electrical behavior of tempered steel into every detail of consideration which urged itself. We 

availed ourselves, moreover, of additional criteria given by the density 

relations of the whole or of similar parts of the bodies quenched. . At 

every stage of our work we reached data alike in character both for 

steel and for glass. With these results we are further justified in 

maintaining that sudden cooling of steel is accompanied by a strain effect 

of a distinct and individual kind and of an intensity sufficient to account for the electrical properties of steel (thermo-electric and resistance constants) such as we have found them.

In one of the earlier paragraphs of the present paper we pointed out 

that in its divers relations to hardness steel is distinguished from glass. 

To further our investigation it will therefore next be necessary to inquire 

more specifically into the causes of hardness itself, and at the same time 

to endeavor to throw light on the mysterious transformations of carbon.

§ III. THE HYDRO-ELECTRIC EFFECT OF TEMPER.

Our original object in writing these papers was that of elucidating 

questions having reference to the carburation of steel, from a purely 

physical standpoint. The-reasoning available to the physicist is, however, of an analogical kind, and therefore as dangerous as it is fascinating. 

Hence, in view of the time already spent, it seemed expedient to en1 If "quenching" means sudden cooling, then if the solid quenched be massive and, 

thick the deep layers cannot be quenched iu virtue of their position.

(121) '
122 WASHINGTON LABORATORY. [BULL. 42.

deavor to cut more nearly down into the heart of the inquiry and to 

determine directly the carbon relations of steel as a function of the 

temperature (0° to 400°, 400° to 1000°) and of the time of annealing, 

and to do this with full reference to the physical occurrences observed 

in the first and second phases of the phenomenon. So far as we know, 

M. Caron 1 alone has occupied himself with similar work; but his researches, being largely restricted to the extreme states "hard" and 

" soft," are incomplete. The carburation effect of annealing at measured 

temperatures during stated times is quite unknown.

Glass hard steel rods about O.lcm in diameter and tempered uniformly in the way described elsewhere 2 were each broken into four 

nearly equal parts.and four samples of hard steel identical in composition and temper were thus obtained. These samples were annealed at 

20° (glass hard), 100° 4h, 200° lh, 360P lh , 1000° 5m, respectively. Having 

treated these with cold dilute hydrochloric acid, we found that the 

rods annealed at 20° and at 100° dissolved without perceptible residue 

to a clear liquid; those annealed at 200° left a trace of flocculent carbon. 

Rods annealed at 360° yielded flocculeut carbon in considerable amount; 

rods annealed at 1000°, finally, a comparatively copious and heavy 

carbon precipitate. The residues were collected in a weighed Gooch 

crucible (asbesttis filter), thoroughly washed in the usual way,3 dried, 

weighed, ignited in oxygen, again weighed, and the loss of weight on 

ignition estimated as carbon. The results thus obtained are sufficient 

for the present purposes : *

TTncombined (graphitic) carbon per gramme steel, c.

20°,oo

< 0.0007

100°,4h

<0. 0007

200°, lh

0. 0009 0. 0021

1000°, r. 

0. 0047

In a second series of similar experiments we found 

UncomMned (graphitic)

 carbon per gramme steel, c. 0. 0001 0.0005 0. 0005 0. 0014

450°, 1"

0. 0009 0. 0033

(soft).

0. 0053

In general, c increases at an accelerated rate with temperature. The, 

large datum for the commercial state, as compared with the smaller 

values of c for steel softened by mere heating to redness, is an interesting 

feature of these results. The importance of the time effect is also to be 

noted. Temperatures as low as 100°, when acting on hard steel for long 

intervals of time (10b ), produce perceptible precipitation of the carbon 

in steel.

1 Caron: Comptes-rend., LVJ, pp. 43,211,325,1863.

2 Bull. 14, U. S. Geol. Surv., p. 29, 1885; Bull. 27, U. S. Geol. Surv., p. 30, 1886.

3 Using dilute HC1, not water, solution KOH, alcohol, and ether. See Blair : Report of the Board on Testing Iron, &c., I, p. 248. Washington, 1881.

(122)
BARUS ASD SUDDEN COOLING OF GLASS AND STEEL. 123

On closer inspection it appeared that steel annealed at 100° is, cseteris 

paribus, more easily soluble than glass hard steel ; steel annealed at 

200° more easily soluble than steel annealed at 100°, and steel annealed 

at 360° more easily soluble than steel annealed at 200°. In other words, 

the»rate at which solution takes place in general increases as temper continually decreases. These curious results were substantiated by annealing one-half of short glass hard rods (ca. 5cm in length) at red heat on 

dissolving in HOI, the diameter of the soft length is diminished more 

rapidly than the diameter of the hard length. The diminution is usually 

greatest near the middle of the rod, where hard and soft parts meet, 

showing probably that local galvanic action here produces a perceptible 

result. At the same time steel annealed for hardness at a temperature 

in low redness is probably more soluble than steel in any other state of 

temper, hard or soft. Examples are given in the next table.

If we define the rate of solution as the mass dissolved per unit of area 

per unit of time, then in case of two submerged cylinders, for which 

during the time t the radii are reduced from p0 to p and from p0 to p', 

respectively, the rates, cseteris paribus, will be to each other as corresponding values of the expression 

-d

2zrp

Po-p 

po p'

The following table contains some of the results obtained with rods 

in the hard (h) and the soft (s) states, respectively, dissolved iu acid, 

HC1, under identical conditions, m refers to the middle parts of the 

rods, concerning which mention has already been made. These ratios 

are subject, of course, to large variations (1 to 20), depending on the 

method of annealing, &c. The table is a fair exhibit of average values. 

The rods are lettered A, B, C, D.

TABLE XII. Rates of solution of hard and soft steel.

[Original diameter, 2po = '>. 12Grm .]

Diameter.

h......

m .....

s ......

h......

m .....

s ......

h......

m .....

s ......

A.

o. in

0.101

0.102

0.101

0.080

0.091

0.069

0.045

0.007

B.

0.111

0.100

0.103

0.100

0.084

.0.092

0.071

0.045

0.070

C.

0.110

0.098

0. 102

0. 100

0.083

0.091

0.073

0.043

0.070

D.

0.110

0. 100

0. 1.03

0.099

0.081

0.090

0'-072

0.044

0.071

Rates.

A.

1.0

1.7

l.G

1.0

1.7

1.3

1.0

1.4

1.0

B.

1.0

1.7

1.5

1.0

1.6

1.3

1.0

1.5

].0

C.

1.0

1.8

1.5

1.0

1.6

1.3

1.0

1.6

1.0

P1.0

1.6

1.4

l.-O

1.7

1.3

1.0

1.5

1.0

Mean 

rate.

1.0

1.7

1.5

1.0

1.6

1.3

1.0

1.5

1.0

(123)
124 WASHINGTON LABORATORY. ffiULL. 42.

TABLE XTI. Rates of $oluii~n of hard'and soft sled Continued. 

[Original diameter, 2pn = 0. ]2f>cm .]

Diameter.

h ......

/i......

h......

A.

0.122 

0.115 

0.116 

0.103 

0.090 

0.052 

0.078 

0.038

B.

0.123 

0.116 

0.116 

0.108 

0.090 

0.061 

0.077 

0.029

C.

0. 122 

0.115 

0.116 

0.106 

0.089 

0.052 

0.077 

0.028

D.

0.122 

0.113 

0.115 

0.104 

0.090 

0.058 

0.076 

0.042

Kates.

A.

1.0 

2.7 

1.0 

2.3 

1.0 

2.0 

1.0 

1.8

B.

1.0 

3.3 

1.0 

1.8 

1.0 

1.8 

1.0 

2.0

C.

1.0 

2.8 

1.0 

2.0 

1.0 

2.0 

1.0 

2.0

D.

1.0 

3.2 

1.0 

2.0 

1.0 

1.9 

1.0 

1.7

Mean 

i ate.

1.0 

3.0 

1.0 

2.0 

1.0 

1.9 

1.0 

1.9

[Original diameter, 2po = 0. 082cra .]

h......

8 ......

h...... 

s ......

h......

8 ......

0.077 

0.070 

0.070 

6.060 

0.043 

0.000

0.077 

0.065 

0.070 

0.051 

0.041 

0.000

0.078 

0. 066 

0.070 

0.059 

0.044 

0.000

0.076 

0.068 

0.070 

0.051 

0: 043 

0.000

1.0 

2.4 

1.0 

1.8 

1.0 

2.1

1.0 

3.4 

1.0 

2.6 

1.0 

2.0

1.0 

4.0 

1.0 

1.9 

1.0 

2.1

1.0 

2.3 

1.0 

2.6 

1.0 

2.1

1.0 

3.0 

1.0 

2.2 

.1.0 

2.1

From these results we inferred that hard and tempered steel would 

probably be distinguishable hydro-electrically; that, for the first phase 

of the phenomena of annealing, at least, this distinction might be more 

delicate than the estimation of precipitated carbon. To test this inference we selected the rods Nos. 1 to 12, quenched uniformly glass 

hard by our method. These were then broken in the middle and the 

first half of each rod was left in the glass hard state. The other halves 

were annealed in pairs at 20°, 100°, 4h , 185°, 360°, 450°, 1000°, respectively. In order to anneal these (long) rods uniformly, we used a special 

device by which they were drawn vertically upward through a zone of 

constant temperature by clock work. If li be the height of tin's zone 

and p the radius of the disk or drum revolving once an hour, then

h

t = 27tp

is the time of annealing in hours. Again, if we make h 2?r, then the 

time of exposure in hours is the reciprocal of the radius of the disk in 

centimeters. The great advantage of this method of annealing is that 

it requires but a very small zone of constant temperature; 1 it is therefore applicable at all temperatures and almost invaluable for high temperature work (500° to 1500°), where zones of a definite constant temperature are not easily produced. In this way we obtained six pairs 

of hydro-electric couples, each of which consisted of glass hard steel and 

the same steel annealed at one of the temperatures specified. Onr first 

results were investigated with a zero method, and showed clearly that

1 2 it X it (0.3) or even a narrower cylindrical figure being sufficient,

G1U

(124)
UARUS AND STKOUHAL.] SUDDEN COOLING OF GLASS AND STEEL. 125

annealed steel is hydro-electrically positive with reference to hard steel 

and that the electromotive force increases with the difference of temper. 

But in view of the large polarization discrepancies incident to these 

measurements, the electrometer is preferable to the zero instrument. 

Thefollowingresults were obtained withMascart's apparatus adjusted to 

indicate 0.001 volt accurately. The electrodes of the steel couple were 

immersed in a concentrated solution of pure zinc sulphate contained in 

a (J tube, the two limbs of the tube receiving the two steel wires. We 

kept them scrupulously bright by repeated scouring with sand paper. 

In the tables we give the electromotive forces, e, of the divers couples of 

hard and tempered steel, as well as the probable mean error, 6 e, of 

each. The means of the two values of e for each temperature of annealing are given in the second horizontal row and fairly exhibit the hydro-electric effect of temper in question. .

The following data are the mean results of four sets or measurements 

of five observations per set. The rods were scoured before beginning 

the first and the third of these sets.

Annealed at 1000^ ......£

No.

9

10

1

' 2 

3

4 

5

G

7

8 

11 

12

eXIO3

± 4

+ 13

+ 12

- 2 

+ 19

+20 

+30

-1-34 

+35

+ 40 

+49

+54

So X 103

±4

±5 

±3

±1 

±3

±3 

. ±3

±3

±4 

±4

Mean 

eXIO3

£ ±6.009

I +0. 000

\ +0. 020

j +0. 035

|+0.037

1+0.052

The following data are the mean results of four sets of five observations per set; rods scoured before commencing each set of measurements:

Annealed at 190° ....... £

Annealed at 360° ........ 5

Annealed at 1000° ...... J

No.

9

.10

1

2

3

4

5'

6

7

8

11

'12

CX103

4- 5

± 2

+ 8

+ 7

+20 

+24

+ 34

+27

+ 35

+43

+51 

+05

(5e X 103

±3

±1

±3 

±2

±5

±1

±2

±2-

±2 

±5

Meon 

eXIO3

I ±0.003

|+0.007

^+0.022

| +0.030

|+0.039

| +0. 058

(125)
126 WASHINGTON LABORATORY. . 49.

The following data, finally, are the mean results of two sets of three 

observations per set; rods scoured before commencing each set of 

measurements:

Annealed at 100°. ....... 5

A nTioalArl nf 1 0OO )

Annealed at 1,000° ....... 5

No.

9

10

1 

2 

3

4 

5

6

7

8 

11

12

eXlO3

-*- 2

. ± 4

+ 6 

+ 16

+25 

+ 30

+ 34 

+37

+ 39 

+59

+G5

6e X 103

±2 

±1 

±3

±1

±2

±1 

±2

±2 

±6

Mean 

e X 103

I ±0.003

| +0. OOC 

I +0. 021

1+0.035

I +0. 038

£ +0. 002

The electromotive forces here encountered are small. It is necessary 

to take extreme precautions against all sources of error; otherwise mere 

discrepancies of polarization will exceed the largest values of electromotive force (e) found. If the parts of the liquid in which the steel 

wires are immersed differ at all in composition we may look for a difference of potential at the surface of separation of those parts. The number of such surfaces in a solution of solid liquid or gas may be indefinite. Hence it appeared desirable to repeat the above experiments 

with distilled water in place of zinc sulphate, to exchange the limbs of 

the U tube twice for each series of measurements (commutation), and to 

submerge equal surfaces of steel electrode in all cases. The results 

follow:

Annealed at 100° ........ J

Annealed at 450°. . ...... | 

Annealed at 1000° ...... £

No.

9 

10 

1 

2 

3 

4 

5 

G 

7 

8 

11 

 12

 e X 103

± 18 

± 28 

+ 12 

+ 28 

+ 33 

+ 20 

+ 93 

-\ 85 

+128 

+ 82 

+166 

+205

fie X 103 .

± 5 

± 9 

± 7 

± 8 

ill 

± 6 

±15 

± 9 

± 5 

± 3

Mean 

0X103

| ±0.023 

1+0.020 

| +0. 027 

\ +0. 089 

|'+0. 105 

\ +0. 185

A few supplementary data are contained in the next table, where Nos. 

I and II are (+) iron /( ) steel couples, both metals in 'the soft state; 

No. Ill, a couple of nominally identical iron wires; Nos. IV and V, 

couples consisting of steel in the commercial, dr^wn state (+}, and the

(126)
BAKUS AND BTROUHAL.] SUDDEN COOLING OF GLASS AND STEEL. 127

same steel softened by heating to redness ( ). The couples are immersed in water.

I.

eXlO3

+26 ±3

II.

ex 10s

+63 ±2

in.

eXlO3

±20

IV.

ex 10s

-69±5

V.

eXlO3

-65±12

The general results of these measurements are in accordance; the 

variations of potential, when taken as a whole, regular and decided. 

They show that as hardness increases the hydro-electric position of steel 

moves continually in an electro-negative direction. The electromotive 

forces encountered are larger for the electrolyte distilled water than for 

zinc sulphate. The total range of variation in the former case (water)

may exceed 0.25 volt. For zinc sulptiate it scarcely reaches one-third 

of this amount and decreases as the time of immersion increases. After 

the first immersion, moreover, the original electromotive force is not 

fully restored even by rubbing the electrodes.1 When steel is immersed 

in water the effect of repeated scouring seemed to be an increase of 

electromotive force. But these and like annoyances, which make the 

study of polarization phenomena unsatisfactory, are too well known to 

need further comment here.

If we avail ourselves of the observations-made above on the rate of 

solution of tempered steel, we may infer consistently with all the facts 

adduced that, since the tempered electrode is covered with hydrogen2 

at a greater rate than the hard electrode, the former must be positive 

with respect to the other; that the phenomena in hand are mere effects 

of polarization. In other words it is permissible to assume that the 

continuous variation of mechanical texture producible by annealing 

is the cause of corresponding variations of the rate at which hydrogen 

is deposited on the submerged metal; that the electromotive forces observed are expressions of this hydrogen polarization and bear no immediate relation to the electro-chemical character of the steel electrode.

Onthe other hand the dependence of the hydro-electric position of steel, 

ceeteris paribus, on,the amount of free carbon contained is sufficiently 

obvious to conflict with this view. To facilitate comparison we insert 

the following table. Here c denotes the number of grammes of free carbon per gramme of steel; e and e' show the difference of potential between 

steel tempered and steel hard when plunged in zinc sulphate and in 

water, respectively; A is the density, s the specific resistance, a, th e

'After long exposure of the wires to air the original electro moti\Te force again appears.

2 Hydrogen accumulates, visibly on the -j- electrode 'When both are inijflersed in zinc 

gulphate,
128 WASHINGTON LABORATORY. [BULL. 42.

resistance temperature coefficient, li the thermo-electric hardness of 

wires of the same kind of steel, a and li are obtained by calculation.

TABLE XIII. 

[Diameter, 2 p=Q. 081.]

Annealed 

from hard at 

o 

2000 .......

100,1". .......

100, 13".......

190, 4". .......

190, 4", 30 ....

Do.........

3^0

450,1"........

530...........

690...........

810..'.........

1,000.........

Commercial..

c

0. 0001

0. 0003

0. 0007

0. 0017

0. 0009

0. 0040'

0. 0053

e

0.000

0.006

0.020

O

n'w

. 0.038

0.057

A

7. 6547

7. 6G6G

7. 6745

7. 6841

7. 6808

7. 6848

7. 6806

7. 7190

7. 7227

7. 7272

7. 7586

7. 7705

7. 7268

s

43 9

39.3

Q 1; *>

30.8

97 1

97 1

20.7

18.4

18.2

17.2

17.6

18.6

16.3

a

0. 0017

0. 0018

0. 0020

0. 0023

0. 0027

0. 0027

O ftAQQ

0. 0036

0. 0036

0. 0038

0. 0037

0.0037

0. 0039

h

IB 1

16.2

14.6

12.7

11.2

11.2

8

K

7.6

7.5

7.1

6.7

e'

0.000

0.020

0 089

0.105

0.185

0.252

When steel of a given kind is operated upon, and total carbon therefore a fixed quantity, the variable c affords a comparatively convenient 

means for detecting the presence and amount of chemical change; but 

it is highly probable that a much clearer insight into the nature of the 

decomposition of carbide produced by annealing hard steel would be 

obtainable from a study of the character and quantity of the hydrocarbons 1 (gaseous liquid) volatilized during solution. They accumulate 

in copious amounts long before the precipitation of carbon is perceptible, or even when no appreciable precipitation occurs, If we regard c

and e or e1 correlated, then we have in hand an example of an exceedingly remarkable decomposition, which may'be regarded as incipient in 

hard steel, even at ordinary temperatures, which is a certainly perceptible occurrence after annealing at only 100°, and which becomes more 

and more definitely marked and distinct as the temperature and time 

of annealing increase. The anomalous character of this species of decomposition, when occurring in a rigid solid, we have already fully pointed 

out. To obtain further information it is essential that the variable c 

be investigated minutely. We remark that the critical difference between the thermo-electric (Ji) and the hydro-electric (c) behavior of steel 

is well shown by constructing li as a function of e'. This is done in figure 

10, which also contains c in its relations to e'.

1 The liquid and volatile constituents seern .to increase in amount as the steel dissolved is harder.

(128)
B&RVB AND STKOUHAL.] SUDDEN COOLING OF GLASS AND STEEL. 129

FIG. 10. Diagram illustrating the relation of graphitic carbon and thermo-electric hardness to the

hydro-electric position of stoel. 

RETROSPECTIVE REMARKS.

The present results have materially substantiated our earlier views at 

every essential point. We may, nevertheless, further point out the presence and the importance of the strain effect by the following simple 

considerations :

The mass constants of the three types of cast iron, the extreme gray, 

the intermediate mottled, and the extreme white, range between the 

maximum density of 7.6 for white cast iron and the minimum density of 

6.9 for gray cast iron. Density, therefore, increases in marked degree in 

proportion as total carbon is more and more nearly combined (from 

''gray" to u white"). Quite the reverse of this is true for steel, where 

density decidedly decreases as total carbon is more and more nearly combined (from soft to hard). This discrepancy is the temper strain, a strain 

of dilatation, which, in Chapters I and II, we carefully compare with the 

analogous behavior of glass. It is to be remembered that the given 

differences of density apply even to parts of the same cast of iron,1 when 

these parts are respectively cooled rapidly (white) or slowly (gray).

With these general indications of the occurrence of stress, it is an important desideratum to obtain some estimate of its value. One method 

premises that the work done in mechanically expanding steel or glass 

from normal density to quenched density is equivalent to the work done 

by heat in effecting the same expansion. Here we have

where in one case unit of mass is acted on by a force p dynes per square 

centimeter during the volume increase dv cubic centimeters j where, in 

the other case, an identical total volume increment (J*dv} is produced

i Karsten : Eisenhuttenkunde, Bd. I, 3. Aufl., p. 581 ff, 1841. 

Bull. 42 9 (129)
130 WASHINGTON LABORATORY. [BULL. 42.

by an excess of temperature T degrees centigrade, applied to the same 

unit of mass and of mean specific heat c. A is Joule's equivalent. If, 

instead of variable p, we employ a mean constant value, P, and put for

T the thermal value rWefind

Here

A = 42 x 106, c = 0.2, 3a = 25 x 10-° 

hence we obtain

P=320 x 109

dynes per square centimeter, or circa 300,000 atmospheres. This is 

an absurdly large value and shows that in case of thermal expansion 

internal work is done which is not registered in mere volume increase. 

We obtain very plausible stress values by introducing the elastic 

properties of glass or steel, probably because we are here relatively 

free from hypotheses. The compression (negative expansion) produced 

by quenching glass or steel is given in Tables X and XI, § II, and 

may be accepted as 5 x 10~3. The volume resilience of glass and 

of steel, according to Professor Everett's 1 measurements, is 4 x 1011 

and 2 x 1012, respectively. Hence, if the force resisted in producing the 

volume increment of quenching be equivalent to the force producing the 

identical compression, we find P=10 x 109 dynes per square centimeter for steel and P=2 x 109 for glass. Now, the tenacity of steel is 

8 x 109 per square centimeter; the tenacity of glass, 0.6 x 109 per 

square centimeter. The ratio of stress to tenacity is therefore 1.3 for 

steel and 3.3 for glass. This shows that in both cases stress and tenacity 

are of the same order, and that stress is in excess, and but for the peculiarly favorable and resisting arched structure of the quenched globule

would give rise to rupture in glass certainly, very probably also in steel. 

These results are estimates and are in accord with the observed explosive 

property of the Prince Eupert drop, and with the less pronounced tendency of steel to crack on quenching. We may infer, therefore, that 

quenched glass and quenched steel are under mean stress intensities of 

several thousand atmospheres; and in discussing the corresponding 

viscous properties of these substances they must be brought into relation with these high intensities of peculiar stress.

We call attention, in concluding, to the deductions of our earlier paper: 

"The annealing of steel, considered physically, is at once referable to 

the category of viscous phenomena. In the ordinary cases of viscosity 

measurements the phenomenon is evoked by sudden application of 

stress (torsion, flexure, tension, volume compression, &c.) under conditions of constant viscosity; in the case of annealing, by sudden cle-

' Everett: Phil. Trans., p. 3G9,1867. The above are round numbers.

(130)
BAUUS AND BTiiQuiiAL.1 SUDDEN COOLING OF GLASS AND STEEL. . 131

crease of viscosity under conditions of initially constant stress. Thermal expansion interferes with the purity of these phenomena by 

destroying the conditions of existence of the strain which accompanies 

hardness, and this in proportion as the expansion is greater."1

Again, irrespective of the manifestation of mere hardness: "The existence of the characteristic strain in glass hard steel is the cause of electrical effects so enormous that such additional effects which any change 

of carburation may involve may be disregarded, and all electrical and 

magnetic results interpreted as due to variations in the intensity of the 

said strain."2

This deduction applies of course to the first phase of the phenomena 

of annealing, since it is within these limits that the strain in question 

is brought to vanish. With these results in hand we may proceed justifiably toward a study of the question whether the conditions for the 

permanent retention of magnetism in an iron carburet are not the identical conditions for the permanent retention of any strain. If W6 Select 

the temper strain for comparison, we do it not merely because long experience has familiarized us with this strain, but because of the clear 

cut beauty of its manifestations and because of the simplicity of the 

functions which describe it.

WASHINGTON, September, 1886.

'Bull. 14, U. S. Geol. Surv., p. 196. 3 Id., p. 197. 

(131)
THE SPECIFIC GRAVITY OF LAMPBLACK.

BY WILLIAM HALLOCK.

The six samples of lampblack which formed the subject of this investigation were kindly furnished by Mr. Samuel Cabot, manufacturer 

of lampblack, in Boston, as samples of the different grades of commercial lampblack made by him. With the six samples came the following specifications with regard to the source or method of the manufacture of each:

I. Black from kerosene.

II. Black from coal tar naphtha.

III. Black from natural gas.

IV. Black from dead oil. 1

V. Black from dead oil; very hot.2

VI. Black from dead oil; very light and fine.3

In order to get more nearly the pure lampblack, free from oil, &c.. in 

each case, all the samples were washed in benzol, alcohol, and boiling 

water and dried at 180° C.

The following table will show the effects of the above washings; also, 

the percentage of ash, the original weight of the substance after standing 

fifteen hours in a desiccator being 100 per cent.

Number of sample.

Dried at 1800 C.... ......................

Washed with alcohol and dried at 180° 

C.. ........ .............................

Washed with water at 100° and dried at 

180° C. ................................

I.

Per cent. 

08.5

97.0

90. 9

96.9

0.08

II.

Per cent.

99.01 

98. OJ

0.3

m.

Per cent.

99.4

0.45

IV.

Per cent.

90.9

0.08

V.

Per cent.

98.2

0.2

VI.

Per cer-t.

98.5

0.02

^his sample is from the back part of the receiving house, where small furnaces 

are used, and therefore the black is not highly heated.

2 This sample is from houses where the furnaces are very large ; therefore the black 

is exposed to a high degree of heat. It gives a large yield and is a cheap black.

3 This sample is fine black from near the furnaces in the same receivers as IV.

(132) .
HALLOCK.] SPECIFIC GRAVITY OF LAMPBLACK. 133

The portions used for the determinations were washed in benzol, alcohol, and boiling water, dried at 180° C., and weighed after being in the 

balance case long enough to have a constant weight; of this point the 

particulars will be given later.

The specific gravity was determined by the pycnometer, using 10 per 

cent, alcohol as the'liquid. The specific gravity of this was found to 

be 0.9864 at 20°.OC. In each case the sample was weighed dry in the 

pycnometer, then covered with 10 per cent, alcohol and put under 

the receiver of an air pump for several hours, until air was no longer 

given off. A test determination demonstrated that this did not appreciably alter the specific gravity of the liquid. After that the vessel was 

carefully filled, so as not to stir up the carbon settled on the bottom, the 

stopper put in, and the whole was weighed; then the stopper was removed and a small delicate thermometer was inserted into the liquid 

and the temperature noted. The pycnometer was then again closed, 

weighed, &c. Thus there were obtained three readings of the temperature and three weighings, the mean of which in each case served to 

calculate the specific gravity.

In this way the following values were found:

c 1.7668 ^

1.723 , No. IV. J 1.7665 > 1.767 '

 I 1.7670 j

.( 1.7890 \

1.780 No. V. I 1.7887 I 1.789

I 1.7881 J

(- 1.7637 ^j

No. III. { 1.7521 } 1.752 No. VI. \ 1.7636 I 1.764

I 1.7641 J

Too much reliance must not be placed upon these values, owing to the 

fact that the lampblack condenses on its surface a large amount of air, 

which is weighed with it when the weighing in air is made, but is absent 

when it is covered with the liquid. An idea of the extent to which this 

may affect the determinations may be obtained from the following 

statement.

A sample of No. II was taken after the washings and dryings, similar 

to that used for the specific gravity. The original weight is called 100 

percent.

Heated 21'to 180°, then 24h in H2S04 desiccator...................... ......a 93.8

Heated 1" to 180°, then 2h in H2S04 desiccator...... .......................b 98.7

5h in balance case.................................c 100.55

Heated 3h .to 180°, tlien 40"' in H2S04 desiccator............................ d 98.76

2 months in H3SC>4 desiccator .....................e 99.2

Thus it appears probable the dry carbon, free from air, weighs only 98.75 

per cent, (mean of a, &, d) of1 the weight as it comes from the sample tube

(133). 
134 WASHINGTON LABORATORY. [BULL. 42.

and as used above for the specific gravity. This, if it is general, would 

lower the above values of the specific gravity by about 1.25 per cent., or 

0.022.

An attempt was also made to obtain some idea of the size of the 

grains of the black by the rate of sedimentation, on the principle that 

the finer the particles the slower the sedimentation. For example, a 

single particle falls through a liquid with a velocity proportional to the 

square of its diameter (radius).

For this purpose 0.1 gr. of each sample was taken from that used for 

the determination of the specific gravity and placed in test tubes about 

20mm by 120mm dimensions. Upon each was poured 3CC of alcohol, then 

ten shot, 2mm in diameter, were put in each tube to help break up the 

black. After vigorous shaking 5CC of water was added; then the tubes 

were heated till the liquid boiled, placed under the receiver of an air 

pump, and the pressure was reduced till they boiled there, when they 

were left 18h to remove any air which might be condensed on the surface of the carbon. The tubes were then filled with distilled water well 

shaken and stood up to sedimentate.

After standing for the time given in the ninth column, Table I, twothirds of the liquid was poured into another tube and that placed aside. 

The original tube was then refilled with distilled water, well shaken, and 

stood up until the next decantation, and so on, until the contents of the 

original tube would settle in a day or less. Thus each sample was separated into a series of lots of different fineness. The time required by 

these decanted lots to settle is given in Table II.

Unfortunately these results cannot be expressed in a very clear way, 

but in general the following is true:

Sample I. Settles quite completely in fifteen minutes, and hence is 

coarse.

Sample II. Settles iu one day, and is hence much finer than I and III, 

but not so fine as IV, V, or VI.

Sample III.' Same as sample I.

Sample IV. A little finer and slower than No. II.

Sample V.and VI. These two are very nearly alike and are both 

much finer than any of the rest.. Sample VI is, however, decidedly the 

finer of the two.

Of course any sample may behave as if it were coarse when each grain 

is, in fact, an agglomeration of several. This is hardly likely iu the 

the above samples, since, if such were the case, we would be apt to find 

some fine black even in samples I and III.

I am fully aware of the incomplete and primitive character of this investigation, and sincerely hope it may incite some one with plenty of 

time and energy to take up the subject thoroughly and either confirm or 

refute iny conclusions.

(134)
HALLOCK.] SPECIFIC GRAVITY OF LAMPBLACK. 

TABLE I.

135

Number 

of decantation.

1. .........

2.......... 

3..........

4..........

5..........

C. .........

7...........

Number 

of decantatioii.

1..........

2 ..........

3..........

4..........

5..........

G. .........

7..........

Time of decantation.

May 28, 188C, 

11.45a.m. 

12.2 p. m. ....... 

2................

3.25.............

3.55.............

May 29, 1886, 11 

a. m.

Time of decantation.

May 28, 1880, 

11.45 a.m. 

12.2p.m........

o

3.25............. 

3.55.............

May 29, 1886, 11 

a. m. 

12.30p.m.......

Sample I.

Clear after 15 m.

Sample II.

Oi

Ti

do...........

An ...........

....fin ... ....

V( 

Di

Sample V.

....do............... 

....do...............

....do............... 

....do ...............

Very -weakly translucent. 

Very weakly translucent; settles now 

in a few boiirs.

sry translucent.

Sample III.

Clear after 15 in. 

Discontinued . . .

Sample VI.

Opaque .........

....do........... 

....do...........

....do........... 

....do...........

....do ............

Opaque; settles 

now iii a day 

or so.

Sample IV.

Opaque.

Do. 

Do. 

Dimly translucent. 

Do. 

Medium translucent. 

Medium translucent; settles 

now in a few 

bours.

Interval between 

decantations or 

shaking.

1 b. 55 m...... .... 

17 m. .............

1 b. 25 m ..........

Ib. 30m......:...

Total time 

since commenced.

Ih. 55m.

2 b. 12 in. 

4li. 10 m. 

5 b. 35 m. 

6b. 5m. 

7 b. 35 m.

Ob. 5 m.

TABLE II.

Decantation.

1. ............

2.............

3 ............

4.............

5.............

6.............

7.... ........

Sample I.

bour.

'

Sample II.

bour. 

....do .......

....do.......

Sample III.

bour.

Sample IV.

days. 

....do .......

....do .......

tv

. bour. 

....do.......

....do .......

Sample V.

in 5 days. 

....do .........

....do .........

....do.........

Sample VI.

Not in 30

days. 

Do.

in 20 days.

in 5 days. 

Do.

Do.

in 1 day.

(135)
MISCELLANEOUS ANALYSES.

THE PERIDOTITE OF ELLIOTT COUNTY, KENTUCKY.1

[Specimens collected by J. S. Diller and analyzed by T. M. Cbatard.]

A. Peridotite. 

B. Olivine from peridotite. 

C. Pyrope from peridotite. 

D. Ilmenite from peridotite. 

E. Syenite inclusion. 

F. Slaty inclusion.

G. Calcareous sandstone near peridotite dike. 

H. Indurated shale near peridotite dike. 

I. Fine grained, fissile sandstone near dike.

H2OatllO° ..........

H2O at red lieat ......

COa ..................

Ti02 .................

PS08 .................

Cr203 ..... ..........

A1203 .... .............

Fe2 03 ................

FeO. .................

MiiO. .....:..........

CoO...... ............

NiO...... ............

CaO.... ..............

MgO .................

KgO. ..................

Na30... ...... .-. ..' ...

S03 ..................

A.

.............. 8.92

.............. 6.66

.............. 29.81

.............. 2.20

.............. .35

.............. .43

.............. 2.01

........ ..... 5.16

.............. 4. 35

.............. .23

.............. .05

.............. 7.69

..... ........ 32.41

.............. .20

.............. .11

.............. .28

100. 86

B.

.14 i

.66 i

40. 05

.07

.04

.24

.39

2. 36

7.14

.20

Trace

1.16

46.68

.21

.08

99.42

C.

.17

41.32

.16

None

.91

21.21

4.21

7.93

.34

4.94

19.32

j .07

V

100.58

D.

.20

.76

49.32

Trace

.74

2.84

9.13

27.81

.20

.23

8.68

.19

100. 10

'Discussed by J. S. Diller in Am. Jour. Sci., August, 1886.

(130)
MISCELLANEOUS ANALYSES. 137

	E. K G. H. I.

HjOat 110° ..'........ i c 1.40 .85 ...... 1.94

H2 0 at red heat....... > t51 ( 9.00 2.32 8.78 5.17

C02 ...... .............. ...... .88 6.29 .55 ........

SiO8 ................... 60.56 35.53 60.78 41.32 60.25

Ti02 ................... 1.19 -95 .03 .48 .23

P2O6 ................... .30 .08 .09 .08 .10

Cr2 0s .................. ...... ...... ...... Trace ........

A12 03 .................. 16.19 18.23 10.54 20.71 20.18

PesOs .................. 5.19 2.46 3.27 2.59 1.53

 PeO..........:....-.... 2.41 4.81 ...... 5.46 3,42

MnO................... .36 .13 .10 .17 .10

CaO ................... 2.09 21.17 10.15 9.91 .51

MgO ................... 1.30 2.01 1.59 1.91 3.52

K2 0.................... 4.82 1.08 2.36 .88 3.17

Na2O.... ............... 4.78 2.53 1.41 7.19 .39

99.70 100.26 99.78 100.03 100.51

TRENTON LIMESTONE FROM LEXINGTON, VA.

[Collected by H. D. Campbell. Analyses by E. B. Biggs.]

A. Limestone.

B. Eesidual deposit from subaerial decay of limestone.

A. B.

Ignition ................................ 1.08 12.98

C02 ..................................... 42.72 ......

SiOa .................................... .44 43.07

A1S03 ................................... ...... 25.07

Fe2O3 ..-................................ .42 15.16

CaO .................................... 54.77 .63

MgO.................................... Trace .03

KaO .................................... ...... 2.50

.................................. ...... 1.20

99.43 100.64

RESIDUAL DEPOSIT FROM SUBAERIAL DECAY OF CHLORITIC SCHIST 

FROM EIGHT MILES WEST OF CARY, N. C.

[Collected by I. C. Kussell. Analysis by E. B. Eiggs.]

SiOs ............................................... 54.54

A1203 ............................................. 26.43

Fe203 .............................................. 9.04

Ignition ................... .....^.,................. 9.87

99. 88 

(137)
138 WASHINGTON LABORATORY. [uuu,.42.

YELLOWISH BROWN, KAOL1NIZED, DECOMPOSED TRAP PROM FOUE 

MILES WEST OF SANFORD, N. C.

 * 

[Collected by I. C. Russell. Analysis by T. M. Chatard.]

Ignition ........................... ................ 13.26

Si02 ............................................... 39.55

A1203 .............................................. 28.76

Ti02 ......I........................................ .64

P2 05 -.-...-... ...-..................-.........., .10

Fe203 ... .............................^............. 16.80

Cr203 .-....................... .....*................ Trace

MnO............................................... Trace

CaO............................................... .37

MgO... ............................................ .59

Alkali........'..................................... Undet.

100.07

ALTERED FELDSPAR FROM LAUREL CREEK, GA.

[Analysis by T. M. Chataril.]

H30 ............................................... 8.68

Si02 .................. ............................. 4&.25

A1203 -............................................. 36.33

Fe2O3 .............................................. .09

MnO............................................... None

CaO ............................................... 3.17

MgO......................................... ...... .64

K20 ............................................... .26

Na2O .............................................. 2.16-

100.58

FERRUGINOUS ROCK FROM PENOKEE IRON RANGE, 1 WISCONSIN. 

, [Collected by E. D. Irving. Analysis by E. B. Riggs. ]

Si02 .............................................. 15.62"

A1 203 .............. ............................... 4.27

Fe203 --................... ........................ 8.14

FeO .............................................. 32.85

MnO....'...... ..................................... 5.06

CaO ........................................:..... .81

MgO.............................................. 2.66

COa............................................... 30.32

H20 ............................................. .68

100.41

' From NE. J of Sec. 6, T. 45, R. 2 E. 

(138)
MISCELLANEOUS ANALYSES. 139

TWO ROCKS FROM KAKABIKKA FALLS, KAMINISTIQUIA RIVER,

ONTARIO, CANADA.

[Collected by E. D. living. Analyses by E. B. Eiggs.]

A. Black slate, Animlkie formation.

B. Material interstratified with the foregoing.

A. B.

Si02 ................................... 37.73 54.26 '

A1203 ...........................i..... 3.41 2.57

Fe2O3 .................................' 6.42 3.62

FeO .................................. 22.92 19.63

MnO...... ............................ .40 .19

CaO .................................. 1.26 1.07

MgO.................................. 3.98 2.93

 C03 ................................... 18.01 14.93

H20 .................................. 2.74 1.20

C..................................... 3.54 .45

100.41 100.85

MICA ANDESITE FROM A CANON ON THE EAST SIDE OF SAN MATEO 

MOUNTAIN, NEW MEXICO.

[Collected by Capt. C. E. Button. Analysis by T. M. Chatard.]

Ignition .......................................... .14

SiO2 ............................................... 65.78

Ti02 .................................. ............ .27

P20S ............ .................................. .13

A12O3 ............................................. 17.32

Fe303 ............................................. 3.68

FeO .............................................. .46

MnO................ .............................. .32

CaO............................................... 1.66

MgO................................... ............ .47

K2O .............................................. 4.64

NasO.............................................. 5.23

100.10

HYPERSTHENE ANDESITE FROM SAN FRANCISCO MOUNTAINS, ARIZONA.

[Collected by Capt. C. E. Button. Analysis by T. M. Chatard. J

Ignition ................ .......................... .20 '

SiO2 .............'............................!.... 64.82

Ti(^..-.:i......................................... .56

PaOi.............................................. .23

A1203 ............................................ 18.27

Fe203 ............. ................................ 3.48

FeO .............................................. .56

MnO.............................................. .20

CaO ............................................... 2.89

MgO.............................................. .85

NaaO.............................................. 5.05

K20,... ......................................... 2.67

99.78
140'

WASHINGTON LABORATORY. [BULL. 42.

BASALT FROM SIX MILES NORTHEAST OF GRANT. NEW MEXICO.

[Collected by Capt. C. E. Button.. Analyses by T. M. Chatard. Separations of minerals byJ. S.

Diller.l 

A. Basalt.

B. Separated augite.

C. Separated feldspar.

H2 0

Si02 

TiOa 

P306 

A120:

Fe20g

FeO

MnO

BaO

CaO

MgO

Na20

K2O

100.51 99.85 100.65

In B there were traces of Or, Co, and Ni. Analysis C was made from 

only .75 gramme of material.

FULGURITE FROM WHITESIDE COUNTY, ILLINOIS.

A. 

............ .36-

............ 47.54

2.76

............ .51

'3 .......... 16.73

> 3 .... ....... 6.69

............ 6.67

>............ .19

............ .03

............. 8.74

>........... 6.38

).:.......... 2.81

............ 1.10

B.

.20

47.06

1.82

.06

7.77

1.30

QIC:

.20

19. 33

13. 52

.33

.11

C.

.26

52.54

Undet.

| 31. 261

12.34

.28

3.55

.42

[Analyses by F- W. Clarke of material selected by G. P. Merrill.]

Fused glassy

portion. 

Ignition .............................. -.33

Adjacent 

sand.

SiO2 .................................. 91.66

Al203 Fe2 03 ........................... 6.69

CaO...... ............................ - .33

MgO...... .............................. .12

K20 .................................. .73

Na3O ................... ...'... ......... .77

1.01

84.83

9.88

1.16

.13

1.13

1.50

100.68 99.64

The fact of the excess of silica in the fulgurite proper was verified by 

duplicate determinations.

BLUE AND BUFF LIMESTONES FROM QUARRIES OF THE HOOSIER STONE 

"COMPANY, BEDFORD, INDIANA.

[Analyses by F. W. Clarke.] >

	Blue. 

C02 ..................................... 43.08

Si02 ..................................... 1.69

' Fe2 03 .................................... .49

CaO ..................................... 54.18

MgO.......... .............'... ........... .37

P20S ..................................... Trace

Buff.

44.01 

.63 

.39

54.19 

.39

Trace

99.81 99.61

1 Little Fe2 0:i , 

(140)
 . MISCELLANEOUS ANALYSES. 141

Alkalies undetermined. The color of the buff stone is due largely to 

organic or carbonaceous matter.

YELLOW SANDSTONE1 FROM THE ARMEJO QUARRY, COLORADO. 

[ Analyses by T. M. Chatard . ]

A. Analysis (partial) by treatment with strong hydrochloric acid. 

B. Analysis by fusion with carbonate of soda.

A. . B.

Insoluble in HCl-.... 95.54 H2O...... ........... 1.19

Soluble: Si02 . ............... 81.27

Fe203 A12 03 . ......... 2.30 A12O3 . ................ 9.81

CaO...... ........... .17 Fe203i - .............. 1.44

MgO ................ .34 CaO..........'....... .44

HS0. ................ 1.19 MgO ................ .42

 Undet.. ............. 5.43

99. 60 

	100.00

The undetermined portion under B was probably all alkalies.

EIGHT SAMPLES OF VOLCANIC DUST.

[Series A. From 'Galla tin Valley, Mont. Collected by A. C. Peale. Analyses by F. W. Clarke.]

[1. Dry Creek Valley, above mouth of Pass Creek. 2 and 3. From near Bozeman. 4. From near Fort 

<; Ellis.]

1. 2. 3. 4.

H20 ............... 6.45 11.47 6.34 11.96

Si08 ... ............ 46.09 61.82 71.01 60.98

 A1203 , Fe203 ..-.-.'. 14.35 19.86 15.17 21.69

., CaO. .'............. 1.61 1.78 1.19 1.83

CaC03 ... .......... 28.72 ....

MgO .............. 1.29 .51 '.34 . 1.33

I T ,7 5 1.31 2.97 1.23 

5 i 2- 38 2' 77 - 80

99.98 99.13 99.79- 99.82 ' 

[Series B. Material furnisbod by G. P. Merrill. Analyses by J.Edward Wbitfield.]

[I. From Marsh Creek Valley, Idaho. 

H2O lost at 105° . . .

Si02 ...............

Al 2 03) Fe2 03 .......

CaO...... .........

MgO...............

K2O ...............

Na2O ..............

2. From Little Sage Ci 

way, Montana.] 

1. 

........... 1.60

........;.. 6.00

..........'.. 68.92

........... 16.22

........... 1.62

........... 4.00

........... 1.56

99.92

 eek, Montana.

2, 

1.12 

6.50 

65. 56 

18.24 

2. 58 

.72 

3.94 

2.08

100.74 .

3. From Devil's Path3: 

3. 46 

5. 60 . 

65.76 

17.18 

2.30 

Trace 

3.14 

2. 22 -

99. 66

1 In use as a building stone. 

(141)
142' WASHING TON LABORATORY. . [nuu,.42.

[Series C. From mouth of Bazile Creek, Nebraska. Collected by J. E. Todd. Partial analysis by

F. W. Clarke.]

Ignition ...................................... I..... 4. 58

Si02 ................................................ 73.67

AlsOaFegOs-..'...................................... 14.33

CaO................................................ .87

MgO................................................ Trace

Alkalies ...........................................Undet.

LOESS AND CLAYS. 

[Collected by Prof. T. C. Cbamberlin. Analyses by K. B. Eiggs. Material dried at 100°.]

[A. Typical loess, Kansas City, Mo.]

S]0>........................ ......................... 74.46

A1803 ........................................ ...... 12.26

P205 --............................................. .09

Ti03 ................................................ .14

Fe203 ............................................... 3.25

FeO.............................. .................. .12

MnO ............................................... .02

CaO................ ................................ 1.69

MgO............................................... 1.12

K2O ................................................ 1.83

NaaO................'..-.. ................ .......... 1.43

H2 0 (includes H of organic matter) .................. 2.70

CO2 .................................... ............ .49

C. (organic)........................................ .12

S03 ............................ .................... .06

Cl.................................................. .05

99.83 . 

[B. Loess from 300 feet above the Mississippi River, 3£ miles northwest of Dubuque, Iowa.]

Si02 ................................................ 72.68

A1203 ............................................... 12.03

TiOs ....................................... ........ .23

P305 ................................................ .72

Fea03 ................................................. 3.53

FeO ................................................ .96

MnO..........................:..................... .06

CaO................................................ 1.59

MgO................................................ 1.11

K20. ............................................... 2.13

Na2 0 ............................................... 1.68 . H2 0 (includes H of organic matter).................. 2.50

COS .................................................. .39

C (organic) ......................................... .09

S03 -................................................ .51

Cl....'..-...................................:.......... .01

100.22 

(142)
MISCELLANEOUS ANALYSES. '145

[C. Loess from seven foot stratum over brown residuary clay, 350 feet above Mississippi River, near

Galena, Ul.]

 Si09 .............................................. 64.61

A1 2 03 I............................................ 10.64

Pa 06 .......'.....'.......................-.. ..---.-. .06

TiOs.............................................. .40

Fe3 03 .-.-...-..................................... 2.61

FeO .............................................. .51

MnO.. ...^........................................ .05

CaO .............................................. 5.41

MgO.............................................. 3.69

K2 0................ ............................... 2.06

Na2O .............................................. 1.35

H2O (includes H of organic matter) ................ 2.05 < 

C02 .............................................. 6.31

C v(organic) ........................ ............... .13

80s............................................... .11

Cl................................................ .07

100.06

[D. Loess from center of the city, Vicksburg, Miss.]

 Si03 ..:.....................-....'.-............... 60.69

A1 2 03 ............................................. 7.95

PS 06 ...'........................................... .13

TiOa............................................. .52

Fes03 ... -...-...:.-......-....--........-....-.... 2.61

FeO .............................................. .67

MnO...................................... ........ .12

CaO ...........................'................... 8.96

MgO................ .............................. 4.56

K20 ................'.-...........J................. 1.08

Na2 0 ............................................. 1.17

H3O"( includes H of: organic matter) ................ 1.14

'COS ............ ..---....-....---..----..--.......- 9.63

C (organic) ....................................... . .19

S03 ................................................ ,12

Cl..... .......................... .............. .08

99. 62

[E. Red, putty-like clay with pebbles, Milwaukee, Wis.] 

SiO3 ...................'..................... ...... 40.22

A12 03 ............'........................:........ 8.47

P2O5 .-............................................ , .05

TiOB .............................................. . -35

Fe^03 ............................................. 2.83

FeO ................................................ .48

MnO.......... .--..--.....--....---..---......-... Trace

CaO.............................................. 15.65

MgO.... .......................................... 7.80

K2O ............................................... 2.36

Na20 ............................................. .84

H2O (includes H of organic matter) ................ 1.95

C02 ............................................... 18.76

C (organic) ....................................... .32

S03 ..:......... .................................... .13

PI................................................ .06

100.27 

(143)
144 WASHINGTON LABORATORY. [BULL. 42.

[F. Bed pebble clay, from 15 feet below Lower Beach deposit, Milwaukee, ~\Vis.]

SlOa .-..-. ......................................... 48.81

A1 S03 ... .......................................... 7.54

P206 -...................... ................ .......... .13

TlOa.. ..-....... ... ,.-..-....... ........ .45

Fe203 ............................................... -2.53

FeO ................................................ .65

MnO...... ..................................... .^.. .03

Cat) ............................................ :... 11.83

MgO................................................ 7.05

K20 ................................................ 2.60

Na20 ............................................... .92

H2 0 (includes H of organic matter) ................ 2.02

C02 ................................................ 15.47

C (organic)......................................... .38

S03 .................................................. .05

Cl.................................................. .04

100.50 

IRON ORES FROM LOUISIANA.

[Analyses by K. B. Riggs.] 

[A. Brown hematite from Bossier Parish, one-half mile west of Bellevue. J

Ignition............................................ 11.00

Si09 .... ........................................... 27.85

Fe...................... ..:.........-.....-........ 39.65

S................................................... .03

Mn ...................................: ............ .126

P ..................................\................ .226

[B. Brown .hematite from Dr. 'Whitlaw's, four miles west of Greenwood, Caddo Parish.]

Ignition ............................................ 10.26

SiO2 ............ ................................... 6.37

Fe............................ ...................... 50.32

s...................... k .............................. .10

Mn...................'..,....................... . .079

P .................................................. Trace

(C. Brown hematite from Simmons's bed, eight miles south of Homer, Claibome Parish.]

Ignition ............................................ 10.53

SiOa..--.. ......................................... 21.77

 Fe...........1 ....."... ......................... .. 43.17

S................................................... .26

Mn................ ........ ......................... .01

P.;................... ........................... .382

[D. Brown hematite from Moreland's, nine miles southeast of Homer, Claiborne Parish.]

Ignition ............................................ 10.62

SiOa ...... .-.. .......... ..-.......-.--...- -.. 10.97

Fe.................................................. 52.18

S........ ............-^--................... .03

Mn................................................. .026

P........................ ......................... .064

(144)
MISCELLANEOUS ANALYSES. 145

[E. Brown hematite from 500 feet east of Vienna wire road, Lincoln Parish. ]

Ignition .......................................... 9.05

SiCfe............,'................................. 23.20

Fe................................. ......^........ 44.54

S ....................... ............. ............ .09

Mn........................ ....................... .006

P..................................... ........... .859

[F. Brown hematite from Lincoln Seed's place, nine miles northwest of Vienna.]

 Ignition ............ .............................. 9.50

SiOa-.l......,!..'................................ 28.12

Fe................................................ 39.26

S................................................. .03

Mn ............................................... .049

P................................................. .447

[G. Brown hematite from Webster, four miles northwest of Shangaloo.]

Ignition ............................................. 11.25

SiOs ................................................ 18.72

Fe................................................ 45.72

S ................................................. .17

Mn .... .........;......-.....,...:.............. .007

P......................................;.......... .247

[H. Brown hematite from Union Parish, one and a half miles north of Downsville. ]

Ignition .......................................... 11.04

Si02 ............................................... 21.70

Fe...................................:......:...... 43.76

S ................................................. ,03

Mu ............................................... .005

P................................................. .835

[I. Brown hematite from Moroland's, ten miles southwest of Arcadia, Bienville Parish.]

Ignition .......................................... 18.22

SiO3 ............................................... 39.95

Fe...... .......................................... 22.22

S................................................. .17

Mn............................................... .157

P...'.............................................. .072

[J. Limestone from Eayborn's Salt Lick, Bienville Parish.]

SiOa .............................................. .55

Fe203Al203 .......... .............................. 1.61

P305 .............................................. .048

MnO.............................................. Trace

CaO ............................................... 54.09

MgO.............................................. .06

C02 ...............:............................... 44.12

S03 ..-............................................ .05

100.528 

Bull. 42 10 (145)
146 WASHINGTON LABORATORY. [BULL.42.

"NATURAL COKE" FROM MIDLOTHIAN, VA.

[Collected by I. C. Russell. Analysis by E. B. Riggs,]

Water............................................ 1.66

Volatile matter................................... 18.35

Fixed carbon ..................................... 67.13

Ash.............. ................................ 12.86

100.00 

Sulphur ...................................... . 4.70

Water in coal dried forty-eight hours over sulphuric acid, 0.11 per 

cent. Water taken up in forty-eight hours' exposure over water, 3.90 

per cent.

COAL FROM JEFFERSON COUNTY, WEST VIRGINIA.

[Bed about fifteen miles west of Berkeley Springs. Analysis by J. Edward Whitfield.]

Moisture.......................................... 2.30

Volatile matter................................... 10.90

Fixedcarbon ..................................... 81.20

Ash............................ .................. 5.60

100.00 

Sulphur .......................................... .785

No coke j ash, pink and sandy.

THREE COALS FROM GULF, NORTH CAROLINA.

[Collected by I. C.^Russell. Analyses by T\ "W. Clarke. Specific gravity determinations made with 

the Jolly balance by E. L. Howard.]

Upper layer. Middle layer. Lower layer. 

Volatile matter.............. 24.48 24.22 23.94

Fixedcarbon................ 72.44 67.86 66.37

Ash ......................... 3.08 7.92 9.69

100.00 100.00 100.00

Sulphur...................... .99 1.42 3.33

Specific gravity.............. 1.295 1.339 1.359

Coke, good; ash, gray. The coals gain weight on drying at 115°.

\

COAL FROM WALNUT COVE, STOKES COUNTY, NORTH CAROLINA.

[ Analysis by J. Ed ward Whitfleld. ]

Water...................................... .38

Volatile matter ............................. 17.99

Fixed carbon................................ 55.47

Ash....................................'....- 26.16

100.00 

Sulphur..................................... 5.56

No coke. Residue sandy.

(146)
MISCELLANEOUS ANALYSES. 147

" NATURAL COKE" FEOM PUEGATOEY CANON, NEW MEXICO.

[Analysis by R. B. Kiggs.]

Volatile matter.............................. 16.87

Fixed carbon...!............................. 74.18

Ash......................................... 8.95

100.00 

Specific gravity............................. 1.43

'* ' 

TWO SPEINGS, ONE MILE FEOM FAEMWELL STATION, LOUDOUN

COUNTY, VIEGINIA.

I Analyses by E. E. Riggs. Stated in grammes per liter. 1

A.

Per cent, of 

Pound. total solids. Hypothetical combination.

S04 .-............ 1.2865 61.10 KCL.............. .0067

Cl................ .0095 .45 NaCl.............. .0104 '

CO-3.............. .1590 7.55 NaaS04 ........... .2355

SiO2 .............. .0210 1.00 MgS04 ............ .0750

A1203 -............ .0070 .33 CaS04 -........... 1.5052

Ca............... .5235 24.87 CaH2 (C03 )2 ....... .1100

Mg............... .0150 .71 CaC03 ............ .1319

K................ .0035 .17 AlaOs............. .0070

Na............... .0805 3.S2 Si02 .............. .0210

2.1055 100.00 2.1027

	B.

S04 .-............ 1.4050 61.28 KC1-..---. .... .0057

Cl............... .0175 .76 NaCl ............. .0244

CO3 .............. .1730 ' 7.55 Na2S04 ........... .2543

Si02 .............. .0110 .48 MgS04 ............ .0975

A1203 ............. .0105 .46 CaS04 ............ 1.6363

Ca............... .5610 24.47 CaH2 (C03 )2 ...... .1438

Mg.............. .0195 . .85 CaCOs...:...-....' -.1107

K................ .0030 .13 A1203 ............. .0105

Na.............. .0920 4.01 Si03 .............. .0110

2.2925 99.99 2.2942 

	(147)
148 WASHINGTON LABORATORY. [HULL. 42. 

TWO ARTESIAN WELLS, STORY CITY, STORY COUNTY, IOWA.

[Analyses by F. "W. Clarke.'with carbonic acid determinations by K. B. Riggs.] 

[A. "Water from artesian well of Thorkill Henryson. Total solids, 0.3620 gramme to liter.]

Per cent, of 

. Found. total solids. Hypothetical combination.

Si O2 ............... Trace ........ Si Oa .............. Trace

Fe203 Al2 .03 ......... .0135 3.73 Fe2O3, A12O3 ......... 0135

Cl.................. .0010 .27 NaCL.............. .0016

S04 ................. None ........ Na* C03 ............ .0417

Ca............ ..... .0764 21.10 Ca C03 ............. .1910

Mg................. .0324 8.95 Mg C03 ............. 1134

. Na .................. .0187 5.17 

C02 , total........... .2680 C03 60.56 .3612

 (99. 78 per cent, of total

99.78 solids accounted for.)

The CO2 required in the second and third columns is 0.1607 gramme, 

leaving 0.1083 gramme for bicarbonates. The water contained flakes of 

ferric hydroxide.

' [13. "Water from artesian well of Charles "Watkins. Total solids, 0.4710 gramme to liter.]

Per cent, of 

Found, total solids. . Hypothetical combination.

SiOa................ .0250 5.31 Si O2 ............... .0250

Fe2 O3 .............. .0060 1.28 Fe2 O3 .............. .0060

Ca.... ............. .0796 16.90 Ca C03 ............... 1990

Mg................. .0356 7.56 Mg C03 ............. .1246

Na ................. .0501 10.64 Nag COS ............ .1155

K ..................Trace C03 58.12

.4701 

Cl.................. Trace .99.81 (99.81 per cent, of total

C02 , total ........... 3920 . solids accounted for.)

The CO2 required in the second and third columns is .2008 gramme, 

leaving .1912 gramme for bicarbonate.s. The "water contained much sediment. Neither water contained any sulphates.

BECK'S HOT SPRINGS, NEAR SALT LAKE CITY, UTAH,

[Analysis by R. B. Riggs. Stated in grammes per liter, ]

804............

n

co3 ............

SiO2 ... .........

A1203 . ..........

Pi

Msr

K.. ...............

Na.... .........

Li .............

B2 03 ..........

Per cent, ofFound, total solids. Hypothetical combination. 

......... .8405 6.68 Km . :_____ V27m

.......... 6.7438 53.59

.......... .2045 1.63

.......... .0315 .25

........... .0090 .07

.......... .6943 5.52

.......... .1095 .85

.......... .1969 1.57

.......... 3.7549 29.84

np7*o (*f\

.......... Trace

12. 5849 100. 00 

(US)'

Nad.......'..

MgCls- .......

Cads ....... ..

CaS04 ........

CaCOs-. ......

CaH2 (C03 )2 ...

A1 2 03 .........

Si02 ..........

... 9.5506

... .4334

.6957

. .. 1.1907

. . . . 1262

. . . . 1739

... .0090

. . . . 0315

12. 5871
MISCELLANEOUS ANALYSES. 149

WATER OF MONO LAKE, CALIFORNIA.

[Analysis by T.M. Cbatard. Compare old analysis in Bulletin 9, p. 26. 

Specific gravity, 1.0456, 17.°5.1

Stated in grammes per liter.

Per cent, of 

Found, total wolids.

Na.................... ,19.6853 36.790

K..................... .9614 1.795

Ca .................... .0200 .037

Mg....'................ .0551 .103

Als03> Fea03............ .0030 .005

SiO2 ................... .0700 .130

S04 ...... ............. 6.6720 12.470

Cl .................... 12.1036 22.630

B407 .................. .1600, .300

C02 ................... 10.0396 18.770

O for C03 ............. 3.2341 6.090

H2 0 in bicarbonates... . 4683 .880

53.4724 100.000

Hypothetical combination. 

KC1 ............ 1.8342

NaCl .............. 18.5068

NasS04 ..........i- 9.8690

Na2CO3 .............. 18.6720

NaHC03 . ......... 3.9015

Na2B4 07 ........... .2000

CaHa (C03 ) 2 ........ .0810

MgH3 (C03 ) 3 ....... .3349

AlzOsjFezOs-......- .0030

Si03 .-~..........'.. .0700

53.4724

The boric acid is cited from the old analysis, as the material was insufficient for a new determiation.

(149)

INDEX.

A. Page. 

Abertmeteorite .......... ... ........ 95

Actinolite from Corundum Hill, N. C....... 52

Albite from Litchfield, Me ................. 34

Altered feldspar from Laurel Creek, Ga.... 138

Altered gneiss from Corundum Hill, 3f. C... 49 

Altered tourmaline from Hebron, Me....... 15

Armealing,phases of......................101,105

method for high temperatures ......... 124

Annite,analysis of ......................... 25

Armejo Quarry, Colorado, sandstone from.. 141 

Artesian wells, Story City, Iowa............ 148

Auburn, Me., mineral locality.............. 15

B. 

Barus, C., on effect of sudden cooling on steel

and glass............................. , 98

Basalt from near Grant, N. Mex .... ..... 140

Bazile Creek, Nebr., volcanic dust from.... 142

Beck's Hot Springs, Utah................ j. 148

Bedford,Ind.,limestones ................... 140

Bienville Parish, La., limestone from. ... 145 

Boric acid, estimation of.................... 64

Bozeman, Mont., volcanic dust from near... 141. 

Bromine, chlorine, and iodine, indirect estimation of ............................ 89

Bubbles in Prince Eupert drops ..........105,106

C. 

Cancrinite from Litchfleld, Me ............. 29

Cape Ann, Mass.,lithia micas from......... 21

Carburation, effect of annealing on......... 122

Cary, N. C., chloritio schist from near ...... 137

Chatard, T. M., on gneiss dunyte contacts

&o................................... 45

analyses by...... 50,51,52, S3, 54,55,56,136,137,

138,139,140,141-149

Chlorine, bromine, and iodine, indirect estimation of............................ 89

Chlorite from Corundum Hill, N. C......... 51,56

Chloritic schist from near Gary, N. C ...... 137

Cimolite from Norway, Me .................. 18

Clarke, F. "W., researches on lithia micas ... 11 

on minerals of Litchfleld, Me........... 28

analyses by ..28,29,30,31,34,35,40,43,140,141, 

142,146,148

on turquoise from Los Cerillos, N. Mex. 39 

Clay from Milwaukee, Wis........... __. 143,144

Coal,from Gulf,N. C ........1.............. 146

from Jefferson County, "W. Va.......... 146

from Stokes County,N. C .............. 146

from "Walnut Cove,N".C................ 146

Coke, natural, from Midlothian, Va........ 146

Page. 

Coke, natural, from Purgatory Canon, N.

Mex ................................. 147

Contraction in cooled glass, nature of....... 108

Corundum Hill, U". C., gneiss, dunyte contacts of .............................. 45

vermiculite from....................... 51

actinolitefrom ..................._... 52

hydrous enstatite from................. 54

dunyte from............................ 55

chlorite from........................... 56

Cryopbyllite,analyses of .................. 22

D. 

Damourite from Hebron, Me............... 15

Decomposed trap from near Sanford, N. C.. 138 

Density, values of, in hard steel............ 98-100

relations to rate of cooling.............. 99

relations to resistance.................. 100

of iron carburets........................ 129

Devil's Pathway, Mont., volcanic dust from. 141 

Diller, J. S., examination of cancrinito and

elaaoliteby ........................... 30

examination of hydronephelite by ..... 31

examination of turquoise from Los Cerillos, N. Mex., by......................' 39

examination of 1 ucasite by............. 53

Dry Creek Valley, Montana, volcanic dust

from................................. 141

Dubuque, Iowa, loess from near............ 142

Dunyte from Corundum Hill, N. C......... 55

E. 

Elteolite from Litchflold, Me................ 28

Elasticity of strained glass.......:........ 130

Elliott County, Ky., peridotite............. 136

Enstatite from Corundum Hill, N. C........ 54

F. 

Farmwell Station, Va., springs near........ 147

Feldspar, altered, from Laurel Creek, Ga... 138 

Fort Ellis, Montana, volcanic dust from near 141 

Fulgurite from Whitesido County, 111...... 140

G. 

Galena, HI., loess from near................ 143

Gallatin Valley, Montana, volcanic dust

from ................................. 141

Gneiss dunyte contacts of Corundum Hill.. 45 

Gooch, F. A., on separation and estimation of

boric acid &c ........................ 64

on separation of lithium from potassium 

andsodium........................... 73

Grand Rapids, Mich., meteorite from ...... 94

Grant, N. Mex., rocks from................ 140

Gulf, N. C., coals from..................... 146

151
152 INDEX.

H. Page. 

Hallock, "W., on specific gravity of lampblack...........;..................... 132

Hebron, Me., mineral locality.............. 14

Hydro-electric effect of temper............ 121,127

Hydronephelite, description of............. 31

Hydrous ^nstatite from Corundum Hill.... 54

Hypersthene andesite from San Francisco

Mountains........................... 139

I. 

Iodine, indirect estimation of............... 89

Iron of doubtful nature.................... 96

Iron ores from Louisiana..................144,145

Irons, two new meteoric.................... 94

j: 

Jefferson County, Tenn., pseudo-meteorite

from.................................. 96

Jefferson County, W. Va., coal from........ 146

K. 

Kakabikka Falls, near Ontario, Can., rocks

from.................................. 139

Kansas City, Mo., loess from............... 142

L.

Lampblack, specific gravity of............. 132

Laurel Creek, Ga., altered feldspar from... 138 

Lepidolite, from Rumford, Me.............. 12

from Paris, Me......................... 13

from Hebron, Me ...................... 14

from Auburn, Me ...................... 15

from Norway.'Me ...................... 18

Lepidomelane, from Litchfield, Me.......... 34

from Rockport, Mass .................. 25

Lexington, Va., limestone from ............ 137

Limestone,from Lexington, Va............ 137

from Bedford, Ind ..................... 140

from Bienville Parish, La .............. 145

Litcbfleld,Me.,minerals from.............. 28

Lithiamicas, researches on the............ 11

Lithium, separation of, &c................. 73

Little Sage Creek, Montana, volcanic dust

from.................................. 141

Loess,from Kansas City, Mo............... 142

from near Dubuque, Iowa ............. 142

from near Galena, 111 .................. 143

from Vicksburg, Miss ..........i...... 143

Los Cerillos, TS. Mex., turquoise from...... 39

Louisiana, iron ores from.................. 144,145

Lucasite, description of .................... 53

M. 

Maine, the lepidolites of.................... 11

Marsh Creek Valley, Idaho, volcanic dust

from.................................... 141

Meteorites, description of two new ........ 94, 95

Mica andesite from San Mateo Mountain... 139 

Midlothian, Va., natural coke from ........ 146

Milwaukee, Wis., clay from ..............143,144

Mono Lake, Cal., water of.................. 149

Mount Mica, Me., mineral locality.......... 13

Muscovite from Auburn, Me ............... 17

N. . 

Natural coke, from Midlothian, Va......... 146

from Purgatory Cailon, N. Mex......... 147

Page. 

New Mexico, turquoise from ............... 39

Norway, Me., mineral locality.............. 17

P.

Paris, Me., mineral locality.................. 13

Penokee Iron Range, rock from ............ 138

Peridotite from Elliott County, Ky......... 136

Peru, Me., locality for spodumene.......... 11

Polariscopic character of strained glass.... 109

Potassium, separation of, from lithium &c. 73 

Prince Rupert drops, coloration of....... .102,103

density of, when annealed ........ 102,104,105

certain general properties of........... 112

distribution of density in............... 115

Purgatory Cafion, N. Mex., natural coke

from................'................. 147

QQuantitative distillation, apparatus for..... 64

R. 

Resistance, minimum of, for steel.......... 101

Riggs,R. B., analyses by.. 12,13,14,15,17,18,22,25 

94. 97,137,138,139,142, J43,144,145,146,147,148 

on two new meteorites &c............. 94

Rockport, Mass., mineral locality........... 21

Rumford, Me., mineral locality ............. 12

 S.

Sandstone from Arinejo Quarry, Colorado.. 141 

Sanford, N. C., decomposed trap from ...... 138

San Francisco Mountains, hypersthene andesite from........................... 139

San Mateo Mountain, mica andesito from . 139 

Sodalite from Litchfield, Me................ 30

Sodium, separation of, from lithium &c.... 73

Solution, rate of, in tempered steel.......... 123

Specific gravity of lampblack .............. 132

Stokes County, N. C., coal from............. 140

Story City, Iowa, analyses of water' from

two artesian wells at................. 148

Strouhal, V., on effect of sudden cooling on

glass and steel &c ................. 98

T.

Temper, physical relations of.............. 98,99

hydro-electric effect of................ 121,127

Trenton limestone from Lexington, Va..... 137

Turquoise from New Mexico............... 39

 V. 

Vermiculite from Corundum Hill, N. C.... 51

Vicksburg, Miss., loess from................ 143

Volcanic dust from several localities ....... 141

W. 

"Walnut Cove, N.C., coal from .............. 146

Water, from near Farmwell Station, Va.... 147

from artesian wells, Story City, Iowa... 148 

from Beck's Hot Springs, Utah......... 14 8

from Mono Lake, Cal................... 149

"West Gardiner, Me., mineral locality....... 28

Whiteside County,111., fulgurite from...... 140

"Whitfield, J. E., on indirect estimation of

chlorine, bromine, and iodine, &C..... 89

analyses by............................ 141,146