DEPARTMENT OF THE INTERIOR '

UNITED STATES GEOLOGICAL SURVEY

GEOEGE OTIS SMITH, DIRECTOR

BULLETIN 479

THE

GEOCHEMICAL INTERPRETATION 

OF WATER ANALYSES

BY

CHASE PALMER

WASHINGTON

GOVERNMENT PRINTING OFFICE 

1911

CONTENTS.

Page.

Expression of chemical analyses............................................ 5

Chemical character of water......................................J.......... 9

Base data.............................................................. 9

Water of Lake Champlain............................................... 9

Character formula. ...I................................................. 10

Properties of natural waters............................................ 11

Classification of waters. ................................................... x 12

Form of statement..................................................... 12

Application of statement.............................................. 14

Oswegatchie River water........................................... 15

Shenandoah River water........................................... 15

Miami River water ........ ^.......... 1............................ 15

Maumee River water............................................... 15

Brine from Highland, 111........................................... 15

Youghiogheny River water........................................ 16

Interpretation of analyses ................................................... 16

River waters in the Southern States.................................... 16

Relation of water properties to geologic formations...................... 18

Silica in river waters .................................................. 22

Relation of silica to primary alkalinity. ............................ 22

Silica in waters of the Piedmont Plateau and Coastal Plain of the Gulf

of Mexico...................................................... 23

Other rivers draining areas of crystalline rocks ...................... 24

Ottawa River, Canada. ..................... .^.....^............. 24

Mahanuddy River, India, and Uruguay River, Brazil............ 26

Persistence of silica in river waters................................. 27

The water of Mississippi River......................................... 28

The water of the Great Lakes and St. Lawrence River................... 29

Conclusion................................................................ 31

ILLUSTRATION.

FIGURE 1. Map showing geologic character of the drainage basins of Shenandoah-, James, Roanoke, and Dan rivers......................... .20

3

THE GEOCHEMICAL INTERPRETATION OF 

WATER ANALYSES.

By CHASE PALMER.

EXPRESSION OF CHEMICAL ANALYSES.

Terrestrial waters are essentially solutions of a few salts, and their 

chemical character, like that of solutions in general, depends on the 

nature and proportion of the substances they contain. The interpretation of the chemical character of a water from the results of 

analysis is necessarily uncertain and unsatisfactory if it is based 

merely on the amounts of the radicles determined. In analytical 

chemistry, as in other branches of the science, -the chemist considers 

the inherent properties of the radicles of substances, and hence his 

statement of the results of a water analysis should be framed in 

accordance with the chemical nature and the proportional amounts 

of the radicles determined in a solution of mixed salts. There is no 

lack of information concerning the amounts of the various materials 

dissolved in natural waters and the mutual relations of their parts. 

What the chemist especially needs is a form of statement that will 

adequately express these relations and disclose the true proportions 

of the radicles.

The engineer has always recognized the importance of determining 

the properties of water without recourse to complete chemical 

analysis, and his attention is naturally directed to those properties 

which are objectionable. In 1841 Thomas Clark patented in England a process for removing the objectionable constituents of hard 

waters. The softening agent used by Clark was lime water, the action 

of which depends on a very simple principle. In contact with lime 

water the soluble calcium bicarbonate in hard water is changed to 

insoluble calcium carbonate and precipitated, the hardening constituent, calcium, being removed simultaneously from the hard water and 

from the softening agent.

The reaction may be expressed by the equation 

CaH2 (C03 ) 2 + Ca(OH) 2 = 2CaC03 + 2H20

This process of improving the quality of water at once acquired 

wide popularity. In response to many requests for information 

respecting his methods of examining waters,, in 1847 Clark 1 addressed

1 Clark, Thomas, On the examination of water for towns, for ifs hardness, and for the incrustation it 

deposits on boiling: Chemical Gazette, vol. 5, 1847, p. 100.

5
6 GEOCHEMICAL INTERPRETATION OF WATER ANALYSES.

to friends a circular letter in which he states that his examination 

of -waters involves two processes one for ascertaining the hardness 

of water and one for ascertaining its alkalinity. The degrees of 

permanent hardness, temporary hardness, permanent alkalinity, and 

acidity are now capable of exact measurement by methods which do 

not involve the determination of the constituents of water. In the 

section on the properties of water definite limits, deducible from the 

results of a complete chemical analysis, will be set to the special properties. The limits there, assigned conform.to the measurements of 

hardness and alkalinity if made according to the exact method of 

Hehner as described by Sutton.1 The acidity of water may be determined by direct measurement, made by neutralizing a known quantity 

of the acid water by a standard alkaline solution. Saltness caused by 

dissolved neutral salts is a general property of natural water. Since 

the alkalies and strong acids.contribute largely to this property, it is 

essential that the proportional amounts of the alkalies and strong 

acids be separately determined. From the data thus obtained, the 

full value of the salinity 1the saltness of water may be determined.

It is to be observed that Clark fully recognized the propriety of 

looking to some of the properties of water for information concerning 

its fitness for domestic and industrial uses, and the benefit of his 

invention to modern civilization is beyond estimate. In problems 

involving the chemical action of water it is important to-day that 

the student consider all the properties conferred on water by all the 

substances dissolved in it, for in the totality of its properties lies the 

full power of water as a chemically active agent.

Two forms of stating the amounts of mineral materials dissolved 

in water have been widely used. These forms are typified by the 

following analysis of sea water: 2

Composition of ocean water. .

Amounts assigned to hypothetical combinations.

Combinations.

Sodium chloride (NaCl) ........................

Magnesium chloride (MgCl2); . ..................

Calcium sulphate (CaSO<) ......................

Potassium sulphate (K2SOO ...................

Milligrams 

per liter.

27, 215 

 3,807 

1,658 

1,260 

863 

76 

121

35,000

Amounts assigned to radicles.

Radicles.

Potassium (K)..............

Calcium (Ca) ...............

Sulphate (S0<).............

Chloride (Cl)................

Milligrams 

per liter.

10,710 

390 

420 

1,300 

2,700 

19,350 

60 

70

35,000

1 Volumetric analysis, 9th ed., p. 70.

2 Mean of 77 analyses, by W. Dittmaiyof sea water collected by the Challenger expedition: Challenger 

Report, Physics and chemistry, vol. 1, 1884, p. 203.
EXPRESSION OF CHEMICAL ANALYSES. % 7

The older form, which represents the radicles as grouped together 

in arbitrary combinations, has by no means lost all adherents. It 

seems to be held in especial favor by the engineer because it gives 

the amount of' dissolved material in terms which enable him to determine the corresponding amounts of substances necessary to fit a, 

water for special industrial uses. The geologist, however, long ago 

realized that this form of expressing the chemical'character of a 

water is inadequate to the exacting demands of research and has 

resorted to the form of statement in which the amounts of the radicles 

determined are given as independent units. In other words, he has 

practically abandoned a form of chemical expression and has adopted 

instead a statement of physical results. Chemical literature furnishes abundant evidence that the statement of water analyses in 

a form which does not recognize the proportional reaction capacity 

of the radicles fails to show the chemical character of the waters. 

Waters differing widely in character may be grouped together as 

similar if the classification is based on the preponderance of any 

radicle that may be considered as dominant in a solution of salts or 

on the apparent predominance of two or more radicles selected 

merely because they contribute largely to the weight' of the mixture. 

Such classifications may be interesting; from several points of view, 

but they are unreliable guides to the solution of geologic problems 

involving chemical processes. Furthermore, chemists, whose.attention is fixed on the physical weights of the radicles, which are assumed 

to be free and independent, may easily fail to observe important facts 

concerning the chemical character of waters, especially facts relating 

to geology.

One advantage of the ionic form of stating water analyses is that 

it assigns weights directly to the chemically active parts of the dissolved substances instead of using those parts to build imaginary 

structures. The statement of the amounts of the radicles, however, 

indicates only the chemical composition of a water, not its character, 

for the physical weight of a radicle is no criterion of its chemical value 

in a system of dissolved salts such as exists in water. On the other 

hand, if the radicles are considered not as matter subject only to 

the law of gravitation, but rather as individuals acting together 

under the law of equivalent combining weights, contributing their 

proportional shares to the final balance of the system, the meaning 

of the results of a mineral analysis of water can be expressed clearly 

and precisely.

The reaction capacities of the radicles of the salts dissolved in 

water are the quotients obtained by dividing the weight of each 

radicle by its corresponding equivalent combining weight. The 

reaction capacity may.be more logically determined by using for 

factors the reciprocals of the equivalent combining weights of the
8 GEOCHEM1CAL INTERPRETATION OP WATER ANALYSES.

radicles, according to the practice of Herman Stabler, in interpreting 

the results of water analyses for industrial purposes.1 Stabler defines 

"reaction coefficient" as the chemical reacting power of a unit weight 

of a radicle. .The reaction coefficient of a radicle is the ratio of the 

reaction capacity of 1 part of that radicle to the reaction capacity of 

8 parts of oxygen and is computed as follows: °

Calcium .................................................

Atomic 

weights.

10

1.008

40.09

' 24. 32

Equivalent 

weights.

162-8

1.008= 1.008

40.09 2~ =20.045 

24.32 2 = " 10

Reaction 

coefficient.

l

LOOS" 0' 99"

20.045- - 0499

12.16- - 0822

The other reaction coefficients are similarly obtained.

The product of the "reaction coefficient" by the amount of a 

radicle Stabler calls the "reacting value" of that amount of the 

radicle. These terms are peculiarly adapted to the chemical valuation of radicles determined in mixtures, and they will be adopted here 

in the chemical classification of waters. The following table shows 

the positive and negative radicles usually found in surface waters 

and their reaction coefficients:

Positive and negative radicles, with reaction coefficients.

Positive radicles.'

Aluminum (Al) ......................

Reaction 

coefficients.

0.992

.0358

.1107

.0499

.0822

.0435

.0256

Negative radicles.

Carbonate (C03) .....................

Bicarbonate (HC03 ) ................

Sulphate (S04 ). .....................

Chloride (Cl). .......................

Nitrate (NO8). . .....................

Reaction 

coefficients.

0.0333

.0164

.0208

.0282

Stabler prefixes the letter r to the symbol of a radicle to designate 

the reacting value of the radicle, and the same symbolization will be 

used in this report.

Under the name "milligram equivalents" (that is, equivalents of 

milligrams of hydrogen) chemists have long used the reacting values 

of the radicles for two purposes namely, to determine the accuracy of the analysis of a water and to obtain reliable factors to be 

used hi the construction of hypothetical combinations. Stabler has 

shown that the reacting values may be put to a better use, for he 

has demonstrated mathematically that the analytical results can be

1 Stabler, Herman, The mineral analysis of water for industrial purposes and its interpretation by the 

engineer: Eng. News, vol. 60, 1908, p. 356. Also, chapter on the industrial application of water analyses 

in Water-Supply Paper U. S. Geol. Survey No. 274, 1911, pp. 165-181.
CHEMICAL CHARACTER OF WATER.

 interpreted far more satisfactorily directly from the reacting values 

than from their hypothetical combinations, and he has shown that 

the labor of calculating the amounts of .remedial agents required to 

produce desired changes in the character of a water is thereby reduced 

to a minimum.

CHEMICAL CHARACTER OF WATER. 

BASE DATA.

The investigation of the surface waters of the United States, concluded in 1908 by the water resources branch of the United States 

Geological Survey, has accumulated a store of information concerning 

the amounts of inorganic material contained in the river waters of 

the country. During the progress of the investigation the writer 

studied the composition of the water of many rivers, and though he 

observed great diversity in the composition of the waters, he was 

convinced that the waters in one locality could not be differentiated 

in. chemical character from the waters in other localities if the analytical results were stated in amounts of the radicles determined. He 

is satisfied, however, that the statement of the radicles can be used 

satisfactorily for interpreting the character of water solutions if the 

chemical values involved are made the basis of interpretation, and 

he therefore presents for consideration the chemical classification of 

waters here described. To illustrate the principle on which the new 

classification is based the .results of analyses of the water of Lake 

Champlain will be used, and one of the properties of the water will 

be deduced by direct resort to the chemical values of the radicles 

contained in it.

WATER OF LAKE CHAMPLAIN.

The average results of analyses l of four separate samples collected 

at four different points on Lake Champlain are shown below.

Results of four analyses of water of Lake Champlain.

Analytical results.

Radicles.

Na (K). ......................................................

Ca. ...........................................................

Mg............. ..............................................

Fe............................................................

C03 ..... .....................................................

SO............................................................

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

Colloids (Si02 ) ...............................................

Parts per 

million.

C.I 

14.0 

2.3 

.70

31.0 

7.4 

1.2

3.76

66.52

Interpretation of results.

Reaction 

coefficients.

0.0435 

.0499 

.0822 

.0358

.0333 

.0208 

.0282

"Concentrati 

(milligrams 

gen per lite

Reacting values 

(equivalent to 

milligrams of 

hydrogen). '

0.264 

.699 

.230 

.027 

 1.22 

1.032 

.154 

.034 

 1.22 

on value" 

of hydror). ........ 2.44

1 Leighton, M. O., Preliminary report on the pollution of Lake Champlain: Water-Supply Paper U..S. 

Geol. Survey No. 121,1905, p. 20.
10 GEOCHEMICAL INTERPRETATION t)F WATER ANALYSES.

The weights of the radicles have thus been resolved to values 

which are chemically measurable by a common standard. The unit 

of measurement is the milligram of hydrogen, in conformity with 

the international acceptance of hydrogen as the standard of reaction 

capacity. At first sight the reacting values may seem insignificant^ 

but they disclose an important quality of the water of Lake Champlain. The reacting value of the alkalies (0.264) exceeds the sum 

of the reacting values of the sulphates and chlorides (0.188) by 0.076. 

This excess of alkalinity may be expressed in terms of sodium carbonate by multiplying 0.076, its reacting value, by 53, the combining 

weight of sodium carbonate. The product, 4.02, represents the parts 

of sodium carbonate per million parts of water. Surf ace waters distinguished by alkalinity due directly to the alkalies are not usually 

found in drainage basins whose rocks consist entirely of calcareous 

formations. The excessive alkalinity suggests that the lake receives 

water that has come from the massive rocks of the mountains, and 

that these waters contain carbonates of the alkalies in quantity 

sufficient to overcome all the permanent hardness of the waters 

derived from more recent formations and to render the lake permanently alkaline.

CHARACTER FORMULA.

Different waters are solutions having different degrees of concentration, and the degree of concentration of the water from a given 

source is subject to continual change. The application of the reacting values of the radicles to the character of water is therefore 

restricted to the particular water and to that water at the time it 

was sampled for analysis.

If, however, the reacting values are expressed in terms from which 

the concentration factor is omitted they become capable of wide 

application. Such an expression may be considered the character 

formula for the mixture of salts dissolved in a water. For convenience 100 has been selected as the formula weight, and the 

reacting value of each radicle in the formula is therefore expressed 

as a per cent of the concentration value. This formula weight has 

be,en found to be applicable to the many waters that have come 

under the writer's observation. Thus the character formula not only 

shows at a glance the" chemical proportions of the radicles found in 

a water, but also clearly discloses even slight differences in the proportions of the radicles in waters under comparison, as. maybe seen 

by comparing, for example, the character formulas of the waters cited 

in Table 1, opposite page 14. The changes, moreover, in the chemical proportions of the radicles present in a river water at different stations along its course are brought out in strong relief by the 

use and application of this formula. These changes. are. shown in
CHEMICAL CHARACTER OF WATER, 11

the tabulated character formulas of the Mississippi River water at 

the several stations from Minneapolis to New Orleans. The character formula adopted for the comparative study of water is strictly 

a chemical formula. It invokes the support of no hypothesis, but 

rests solely on the fundamental law of equivalent combining weights. 

In order to show the chemical character of mineral waters with 

especial reference to their therapeutic action, Carl von Than 1 many 

years ago devised a form of expression that was also based on the law 

of equivalents. Von Than's expression involved two separate ratings, 

one for the reacting values of all the positive radicles and one for 

the reacting values of all the negative radicles, the basis of each 

rating being 100. This double rating makes the resulting expression 

too cumbrous for ready interpretation. The character formula here 

proposed refers the reacting values of all the radicles in the system 

of dissolved salts to one aggregate, so that the characterization of 

the water solution is greatly simplified.

PROPERTIES OF NATURAL WATERS.

Nearly all terrestrial waters have two general properties, salinity 

and alkalinity, on whose relative proportions their fundamental 

characters depend. Salinity is caused by salts that are not hydrolyzed; alkalinity is attributed to free alkaline bases produced by the 

hydrolytic action of water on solutions of bicarbonates and on solutions of salts of other weak acids.

All the positive radicles, including hydrogen, may participate in producing salinity; but of the negative radicles only those of the actively 

strong acids can perform a similar function. The principal strong 

acids in natural waters are represented by the sulphates, chlorides, 

and nitrates. Since salinity depends on the combined activity of 

equal values of both positive and negative radicles, and since its 

degree is limited only by the reacting values of the strong acids, the 

full value of salinity is obtained by multiplying the total value of the 

strong acid radicles by 2.

The full value of alkalinity and at the same time due recognition 

of the parent substances which are the source of alkalinity can be 

obtained by doubling the values of the bases in excess of the values 

of the strong acids.

The positive radicles determined in a water analysis, in accordance 

with their properties, fall naturally into three groups, as follows:

Group a. Alkalies (sodium, potassium, lithium). Their salts are 

readily soluble in water. They do not cause hardness. . Group &. Earths or alkaline earths. Calcium and magnesium 

are the chief representatives of this group. Many of their salts are

1 Sltzungsberichte der Kaiserl. Akad. der Wissenschaften [Vienna], Band 51, 2te Abtheilung (1865), 

p. 347.
12 GEOCHEMICAL INTERPRETATION OF WATER ANALYSES.

sparingly soluble in water. They cause the property commonly 

known as hardness.

Group c. Hydrogen. Salts of hydrogen are acids and cause 

acidity in waters.

The groups of positive radicles are measured by the sum of the 

reacting values of their members, and in accordance with the prevalence of the reacting values of the groups of positive radicles in the 

system, five special properties are possible, namely:

1. Primary salinity (alkali salinity); that is, salinity not to 

exceed twice the sum of the reacting values of the radicles of the 

alkalies.

2. Secondary salinity (permanent hardness); that is, the excess 

(if any) of salinity over primary salinity, not to exceed twice the 

sum of the reacting values of the radicles of the alkaline earths group.

3. Tertiary salinity (acidity); that is, the excess (if any) of salinity 

over primary and secondary salinity.

4. Primary alkalinity (permanent alkalinity); that is,-the excess 

(if any) of twice the sum of the reacting values of the alkalies over 

salinity.

' 5. Secondary alkalinity (temporary alkalinity); that is, the excess 

(if any) of twice the sum of the reacting values of the radicles of the 

alkaline earths group over secondary salinity. :

In distinguishing the special properties, the values of radicles of the 

same sign are doubled. By this procedure the positive and negative 

radicles, which together induce the special properties, receive their full 

value. The use of the adjectives "primary" and "secondary" to 

qualify the general properties of the water solution associates naturally the alkalies with the oldest rock formations, of which the 

alkalies are the principal soluble decomposition products, and refers 

the alkaline earths to the more recent formations as their principal 

sources.

The character of natural waters with reference to the lithology of 

the region from which they are derived, to their solvent action on 

minerals with which they may come in contact, to sedimentary 

deposits that they are likely to form, to their effect on industrial 

processes, and to their chemical action in general can best be portrayed by a statement of as many of the five special properties above 

mentioned as may be found, expressed in percentages of their

totality.

CLASSIFICATION OF WATERS.

FORM OF STATEMENT.

The reaction properties of the water solution are fixed by the relative 

values of three of the five groups of radicles producing the five special 

properties of natural waters. The numerical relations of the value 

of the group of strong acids to the Values of groups of positive 

radicles have been made the basis of the following classification.
CLASSIFICATION OF WATERS. 13

Let a, &, d represent, respectively, the percentage values of the 

alkalies, earths, and strong acids. Any one of five conditions may 

exist: d may be less than a; equal to a; greater than a and less than 

a + &; equal to a + &; or greater than a + b. The five classes of waters 

resulting from these conditions are given below, with their attendant 

properties of reaction.

CLASS 4. 

((/equal to a+6.)

2a. .......... Primary salinity.

26........... Secondary salinity.

CLASS 5. 

(d greater than a+6.)

2a........... Primary salinity.

26........... Secondary salinity.

2 (d a 6)...Tertiary salinity (acidity).

CLASS 1. 

(d less than a.)

o

2d........... Primary salinity.

2 (a d)...... Primary alkalinity.

26........... Secondary alkalinity.

CLASS 2. 

(d equal to a.)

2a or 2d..... .Primary salinity.

26........... Secondary alkalinity.

CLASS 3. 

(d greater than a; d less than a+6.)

2a........... Primary salinity.

2 (d a)...... Secondary salinity.

2 (a+6 d).. .Secondary alkalinity.

To dispel any perplexity that may possibly exist in the minds of 

those unfamiliar with the mode here used of expressing chemical 

values that are numerically coordinate, the relations of the properties 

of water to the reacting values of the radicles are stated again in a 

slightly modified form.

CLASS 1. Strong acids less than alkalies.

Property values. 

% Primary salinity 

£ Primary alkalinity 

£ Secondary alkalinity 

Hence:

Total salinity 

Total alkalinity

(d less than a.)

Reacting values.

Strong acids = d 

Alkalies strong acids = a d 

Earths = 6

Strong acidsX2 = 2d 

(Bases strong acids) X2 =. 2 (a+6 d)

CLASS 2. Strong acids equal to alkalies., 

(d equal to a.)

Property values. Reacting values.

$ Primary salinity = Alkalies = a or d 

% Secondary alkalinity = Earths - ='6 

Hence:

Total salinity = Alkalies X 2 = 2 a or 2 d 

Total alkalinity = Earths X 2 =26
14 GEOCHEMICAL INTERPRETATION OF WATER ANALYSES.

CLASS 3. Strong adds greater than alkalies, and less than bases 

((/greater than a; d less than a+6.)

Property values. Reacting values.

£ Primary salinity =Alkalies =a

% Secondary salinity =Strong acids alkalies =d-a

% Secondary alkalinity =Bases strong acids =a-\-b-d

Hence:

Total salinity =Strong acids X2 =2 d

Total alkalinity =(Bases strong acids)X2=2 (a+b-d)

CLASS 4. Strong adds equal to bases, 

(d equal to a+6)

Property values. . Reacting values. 

£ Primary salinity =Alkalies =a 

$ Secondary salinity =Earths =6 

Hence:

Total salinity =(Alkalies+earths)X2 =2 (a+6) or 2 d

CLASS 5. Strong adds greater than bases. 

. (d greater than a-f b.)

Property values. Reacting values. 

J Primary salinity =Alkalies =a

% Secondary salinity =Earths =6 

£ Tertiary salinity (acidity)=Hydrogen =d-(a +6) 

Hence: .

Total salinity =Strong acids X2=2 d

The form in which the analytical results are stated is especially 

serviceable in the practical study of water as a geologic agent. The 

statement shows: First, the properties of" the solution in percentage 

proportions; second, the percentage reacting values of coordinate 

radicles, from which the properties of reaction may be directly derived, accompanied by a statement of concentration values in milligrams per liter; third, the character formula the percentage reacting 

values of the individual radicles determined together with a statement of the concentration value; fourth, the base analyses.

The amount of any radicle may be obtained by using the following

formula:

T> j- i ' . ,., Percentage valueXconcentration value Radicle in milligrams per liter= ° . . r. ^ -. z 

8 ^ 100 X reaction coefficient

or, the amount of any radicle may be obtained by dividing the reacting value of the radicle by its reaction coefficient.

APPLICATION OF STATEMENT.

Waters representing* these five classes are found in nature. Surface waters appear to belong chiefly to the first three classes, class 4 

is represented in sea water and brines and class 5 is exemplified by 

mine waters and by waters of volcanic origin. Examples of waters 

representing these five classes are given in Table 1.
TABLE 1. Classification of typical waters.

Properties.

Tertiary salinity (acidity) . .

Reacting values. 

Groups:

Earths ...............

Hydrogen ...........

Concentration value.

Radicles: 

rNa. ................

rK...................

rNH«. ...............

r Ca..................

r Mg. .................

r Fe. ................

rH...................

iSOt. ...............

rCl.................

rN08 ................

rHCO3 ...............

rC08 ..... ............

Concentration value. 

Base analyses.

Radicles: 

Sodixim (Na) ..........

Potassium (K).. . ......

Ammonium (NH4) ....

Calcium (Ca). .........

Magnesium (Mg). . .....

Iron (Fe) ............

Sulphate (SO4). .......

Chloride (Cl). ........

Nitrate (N03) .........

Bicarbonate (HC03 ) . . .

Bromide (Br) .........

Colloids: 

Silica , (SiOj)..........

Alumina (A12O3).. . ....

Total dissolved solids .

Class 1. 

(d less than a.)

Lake Champlain.a

Per cent. 

15.4 

.0 

.0 

6.3 

78.3

100.0

Per cent. 

10.86 

39.14 

.0 

7.70 

42.30

100.0

Formula. 

} 10. 86

28.65 

9.38 

1.11 

.0 

6.31 

1.39

42.30

100.0

Mg. per 

liter. 

0.264 

.956 

.0 

.188 

1.032

2.440

Mg.per 

liter.

0.264

.669 

.230 

.027 

.0 

.154 

.034

1.032

2.440

Porte per million.

} 6.!

14.0 

2.3 

.76 

7.4 

1.2

31. 0

3.76

66.52

Oswegatchie River at 

Ogdensburg, N. Y.

Per cent. 

17.5 

.0 

.0 

4.0 

78.5

100.0

Per cent. 

10.74 

39.26 

.0 

8.72 

41.28

100.0

Formula. 

f 9.32 

1 1.42

26.03 

12.80 

.43 

.0 

7.77 

.65 

.30 

41.28 

.0

100.0

Mg. per liter. 

0.250 

.914 

.0 

.203 

.961

2.328

Mg. per 

liter. 

0.217 

.033

.606 

.298 

.010 

.0 

.181 

.015 

.007 

.961 

.0

2.328

Parts per million. 

f 4.9 

I 1.3

12.0 

3.5 

.27 

8.8 

.6 

.5 

59.0

8.0

60.8

Class 2. 

(d equal to a.)

Shenandoah River at 

Hillville, W. Va.

Per cent. 

10.5 

.2 

.0 

.0 

89.3

100.0

Per cent. 

5.25 

44.75 

.0 

5.36 

44.64

100.0

Formula. 

4.53 

.72

31.72 

12.07 

.06 

.0 

2.66 

1.82 

.88 

43.76 

.88

100.0

Mg. per 

liter. 

0.262 

- 2. 230 

.0 

.267 

2.265

4.984

Mg. per 

liter. 

0.226 

.036

1.581 

.646 

.003 

.0 

.133 

.091 

.044 

2.180 

.044

4.984

Parts per million. 

5.4 

1.4

32.0 

8.2 

.08 

6.2 

3.0 

2.6 

132.0 

1.3

15.0

140.0

Class 3. 

(d greater than a. d less than 0+6.)

Miami River at Dayton, 

Ohio.

Per cent. 

7.1 

13.5 

.0 

.0 

79.4

100.0

Per cent. 

3.53 

46.47 

.0 

10.28 

39.72

100.0

Formula. 

2.95 

.58

27.85 

18.57 

.05 

.0 

7.87 

1.10 

1.31 

37.89 

1.83

100.0

Mg. per 

liter. 

0.373 

4.910 

.0 

1.086 

4.197

10. 566

Mg.per 

liter. 

0.312 

.061

2.943 

1.962 

.005 

.0 

.832 

.116 

.138 

4.004 

.193

10. 566

Parts per million. 

7.2 

2.4

59.0 

24.0 

.15 

40.0 

4.1 

8.6 

244.0 

5.8

17.0

289.0

Haumee River at Toledo, 

Ohio.

Pet, cent. 

19.3 

56.8 

.0 

.0 

23.9

100.0

Per cent. 

9.65 

40.35 

.0 

21.62 

28.38

100.0

Formula. 

8.44 

1.21

27.75 

12.51 

.09 

.0 

9.81 

11.10 

.71 

28.05 

.33

100.0

Mg. per. 

liter. 

0.983 

4. 107 

.0 

2.202 

2.888

10. 180

Mg. per 

liter. 

0.860 

.123

2.825 

1.273 

.009 

.0 

1.000 

1.130 

.072 

2.855 

.033

10. 180

Parts per million. 

20.0 

4.8

57.0 

16.0 

.27 

48.0 

40.0 

4.5 

173. 0 

2.5

17.0

298.0

Class 4. 

(d equal to a+6.)

Brine: Artesian well, 

Highland, 111.

Per cent. 

86.3 

12.9 

.0 

.0 

.8

100.0

Per cent. 

43.15 

6.85 

.0 

49.58 

.42

100.0

Formula. 

42.04 

1.02 

.09 

3.38 

3.47

4.37 

45.21

.42

100.0

Mg. per 

liter. 

449. 51 

71.39 

.0 

516. 52 

4.38

1, 041. 80

Mg. per 

liter. 

437. 98 

10.63 

.90 

35.19 

36.20

45.53 

470. 99

4.38

1, 041. 80

Parts per million. 

10, 093. 8 

417.7 

15.4 

708.1 

444.0

2, 187. 0 

16, 700. 0 

<*2.6

127.2

20.0

30, 715. 8

Ocean water. &

Per cent. 

78.6 

21.1 

.0 

.0 

.3

100.0

Per cent. 

39.31 

10.69 

.0 

49.84 

.16

100.0

Formula. 

38.49 

.82

1.77 

8.92

4.62 

45. 15 

.07

.16

100.0

Mg. per liter. 

476. 036 

128. 471 

.0 

602. 421 

2.086

I, 209. 014

Mg. per liter. 

466. 021 

10. 015

21. 203 

107. 268

56. 099 

545. 583 

.739

2.086

1, 209. 014

Parts per million. 

10, 710. 0 

390.0

420.0 

1, 300. 0

2, 700. 0 

19, 350. 0

70.0 

60.0

35, 000. 0

Class 5. 

(d greater than a+6.)

Youghiogheny River at 

McKeesport, Pa.

Per cent. 

14.7 

68.6 

16.7 

.0 

.0

100.0

Per cent. 

7.33 

34.32 

8.35 

50.0 

.0

100.0

Formula. 

6.48 

.85

21.33 

10.30 

2.69 

8.35 

47.35 

2.33 

.32 

.0 

.0

100.0

Mg. per liter. 

0.396 

1.853 

.451 

2.700 

.0

5.400

Mg. per 

liter. 

0.350 

.046

1.152 

.556 

.145 

.451 

2.557 

.126 

.017 

.0 

.0

5.400

Parts per million . 

c8. 0 

1.8

23.0 

6.7 

.7 

123.0 

4.5 

1.1

8.5 

7.5

197. 0

Properties.

Primary salinity. 

Secondary salinity. 

Tertiary salinity (acidity). 

Primary alkalinity. 

Secondary alkalinity.

Reacting values.

Groups: 

Alkalies. 

Earths. 

Hydrogen. 

Strong acids. 

Weak acids.

Concentration value.

Radicles: 

rNa. 

rK. 

rNH4 . 

rCa. 

rMg. 

rFe. 

rH. 

rSO4 . 

rCl. 

rN03 . 

r HC03 . 

rC03 .

Concentration value. 

Base analyses.

Radicles: 

Sodium (Na). 

Potassium (K). 

Ammonium (NH4). 

Calcium (Ca). 

Magnesium (Mg). 

Iron (Fe). 

Sulphate (S04). 

Chloride (Cl). 

Nitrate (N03). 

Bicarbonate (HC03 ). 

Carbonate (CO3). 

Bromide (Br). 

Colloids: 

Silica (SiO2). 

Alumina (A1203).

Total dissolved solids.

o Interpretation of results given on p. 9. 

95451° Bull. 479 11. (To face page 14.)

& Interpretation of Dittmar's analyses, p. 6. An acid water. The original report, in terms of radicles, gives the acidity as 22 parts HsSO* per million. <J +Nitrite (NOj).
CLASSIFICATION OF WATERS. 15

The character of the waters of Shenandoah, Miami, Maumee, and 

Youghiogheny rivers is interpreted directly from the results of the 

analyses as reported in Water-Supply Paper 236 of the United States 

Geological Survey.

^Oswegatchie River water. Average of 15 analyses of composite 

samples made up of 10 samples collected on 10 consecutive days, collections taken from April 10 to September 9, 1907. Analysts, R. B. 

Dole, W. D. Collins, and Chase Palmer.

The properties of the Oswegatchie River water resemble closely 

those of the still waters of Lake Champlain, whose primary salinity is 

15.4,primary alkalinity 6.3, andsecondary alkalinity 78.3. Thus Lake 

Champlain, east of the Adirondacks, is receiving primary-alkaline 

waters from the mountains, and the Oswegatchie, flowing from the 

western slope of the mountains, is delivering primary-alkaline waters 

to the St. Lawrence. 

Shenandoah River water. Average of analyses of 36 composite 

samples. Samples.collected daily from September 12, 1906, to September 9, 1907.

As the Shenandoah drams an area whose rocks comprise the older 

limestone formations, the peculiar character of this water is not surprising. Waters in which hardness coincides with alkalinity may be 

formed in other sections of the country by proper admixture of primary with secondary waters.

Miami River water. Average of analyses of 34 composites. Samples collected daily from September 16, 1906, to September 17, 1907. 

The properties are those normal to the water of a river traversing 

sedimentary rocks. The alkalies^re low and, as is common in river 

waters in regions of Carboniferous; rocks, their reacting values exceed 

the reacting value of chlorine.

Maumee River water. Average of analyses of 36 composites. 

Samples collected daily from September 9, 1906, to September 7, 1907. 

Salinity is a very prominent property of the water. The excess of the 

chlorine value over the value of the alkalies, as shown in the character 

formula, is abnormal for .rivers fed entirely by surface streams. This 

peculiarity of the Maumee water is discussed on page 30.

Brine from Highland, Til. This water was collected in October, 

1910, from a Madison County well 1,100 feet deep. The analysis, for 

which the writer is indebted to Dr. Edward Bartow, director of the 

Illinois State Water Survey, is an important contribution to the 

geology of deep-seated salt waters.1 The relative importance of the 

minor constituents is well shown by the new form of interpretation. 

In the original statement, for instance, the calcium and magnesium 

radicles in milligrams per liter are reported to be Ca 708.1, Mg 444.0,

1 For the chemical character of surface waters in Illinois, see W. D. Collins, The quality of the surface 

waters of Illinois: Water-Supply Paper U. S. Geol. Survey No. 239, 1910.
16 GEOCHEMICAL INTERPRETATION OF WATER ANALYSES.

and in combinations the same radicles are distinguished as 

CaS04 2115.5, CaC03 212.0, MgCl2 1033.0, MgS04 875.0. Under either 

form of statement the calcium, by reason of its superior weight, might 

be considered the dominant radicle; direct comparison of the chemical values observable in the character formula of this brine shows, 

however, that as a factor of property magnesium exceeds calcium Ly 

a narrow margin.

YougJiioglieny River water. The high acidity of the Youghiogheny 

indicates that the river receives water from coal mines. The mode 

of expressing acidity by the new system is in perfect accord with the 

mode of expressing other properties. Acidity can not be adequately 

expressed by the so-called ionic form of statement, which is intended 

to show merely the composition of the water, and not its properties.

INTERPRETATION OF ANALYSES.

Some examples, offered to illustrate the application of the principles on which the rational interpretation of water analyses is based, 

will now be presented.

The river waters belonging to the Piedmont Plateau and Coastal 

Plain will be described, the relation of the properties of river waters 

to geologic formations will be considered, the analyses of the waters 

of three great rivers will be interpreted in connection with a discussion 

of dissolved silica hi flowing waters, some of the changes in the character of the water of Mississippi River will be noted, and finally 

the changes in the character of the waters of the Great Lakes will 

receive attention.

RIVER WATERS IN THE SOUTHERN STATES.

The area drained by the rivers of the Piedmont Plateau and Coastal 

Plain extends from James River, in Virginia, to Pearl River, in Mississippi, and comprises about 125,000 square miles. The waters 

.studied were taken from rivers in Virginia, North Carolina, South 

Carolina, Georgia, Alabama, and Mississippi. In the beginning of the 

investigation of these southern waters several serious obstacles were 

encountered, and it is, therefore, advisable to limit the consideration 

of the chemical character of these waters to the analyses made hi the 

later part of the investigation, when conditions were most favorable 

for obtaining reliable results.

Complete analyses of river waters in Southern States appear in 

Tables 2 and 3, one covering the south Atlantic coast rivers from the 

Piedmont Plateau and the other the Coastal Plain rivers tributary to 

the eastern Gulf of Mexico.
TABLE 2. Character of Piedmont Plateau river waters of south Atlantic coast. 

[Analysts, R. B. Dole, W. D. Collins, and Chase Palmer.]

Properties. 

Primary salinity. ...........

Primary alkalinity. ........

Reacting values.

Groups: 

Alkalies ..............

Earths .................

Strong acids. ...........

Weak acids ...........

Concentration value.

Radicles: 

rNa............. ......

rK........... ........

rCa..................

rMg... ........ .......

rFe...................

rSO4 .......... ........

rCL.......... ........

rNO3 ..................

r HCO3 ...............

rC03 .................

Concentration value. 

Base analyses.

Radicles: 

Sodium (Na) ..........

Potassium (K). . .......

Calcium (Ca) ........

Magnesium (Mg) .......

Iron (Fe). ............

Sulphate (S04).. ......

Chloride (Cl). ........

Nitrate (NO3 ). ........

Bicarbonate (HCO3) . . . 

Carbonate (CO3). .....

Colloids: 

Silica (Si02)... :......

Total dissolved solids. 

Number of composites......

Dates.....................

James at Richmond, Va.

Per cent. 

18.3 

4.7 

77.0

100.0

Per cent. 

11.52 

38.48 

9.16 

40.84

100.0

Formula. 

10.37 

1.15 

28.33 

9.45 

.70 

6.17 

2.79 

.20 

40.84 

.0

100.0

Mg. per liter. 

0.280 

.936 

.223 

.993

2.432

Mg. per liter. 

0.252 

.028 

.689 

.230 

.017 

.150 

.068 

.005 

.993 

.0

2.432

Parts per million. 

5.9 

1.1 

14.0 

3.0 

.5 

7.1 

2.3 

.3 

60.0 

.0

18.0

81.7

36.0 

Sept. 17, 1906-Sept. 

22, 1907.

Roanoke at Randolph, Va.

Per cent. 

15.1 

8.7 

76.2

100.0

Per cent. 

11.87 

38.13 

7.54 

42.46

100.0

Formula. 

10.51 

1.36 

22.86 

13.62 

1.65 

4.52 

2.63 

.39 

42.46 

.0

100.0

Mg. per liter. 

0.244 

.784 

.155 

.873

2.056

Mg. per liter. 

0.216 

.028 

.470 

.280 

.034 

.093 

.054 

.008 

.873 

.0

2.056

Porto per million. 

5.0 

1.1 

9.5 

3.5 

.95 

4.4 

2.2 

.5 

53.0 

.0

21.0

74.1

20.0 

Sept. 7, 1906-May 

12, 1907.

Dan at South Boston, Va.

Per cent. 

24.2 

15.3 

60.5

100.0

Per cent. 

19.73 

30.27 

12.07 

37.93

100.0

Formula. 

17.43 

2.30 

19.32 

8.23 

2.72 

5.02 

6.35 

.70 

37. 93 

.0

100.0

Mg. per liter. 

0.283 

.434 

.174 

.543

1.434

Mg. per liter. 

0.250 

.033 

.277 

.118 

.039 

.072 

092 

.010 

.543 

.0

1.434

Parts per million. 

5.8 

1.3 

5.6 

1.5 

1.1 

3.4 

3.2 

1.1 

33.0 

.0

24.0

63.2

21.0 

Sept. 3, 1906-May 

2, 1907.

Neuse at Raleigh, N. C.

Per cent. 

26.2 

15.7 

58.1

100.0

Per cent. 

20.94 

29.06 

13.11 

36.89

100.0

Formula. 

18.79 

2.15 

17.84 

8.13 

3.09 

4.73 

8.07 

.31 

36.89 

.0

100.0

Mg. per liter. 

0.332 

.461 

.208 

.585

1.586

Mg. per liter. 

0.298 

.034 

.283 

.129 

.049 

.075 

.128 

.005 

.585 

.0

1.586

Parts per million. 

7.0 

1.3 

5.9 

1.8 

1.4 

3.4 

4.4 

.3 

35.0 

.0

26.0

68.7

18.0 

Apr. 1-Oct. 1, 1907.

Pedee at Pedee, N. C.

Percent. 

19.2 

25.0 

55.8

100.0

Per cent. 

22.09 

27.91 

9.61 

40.39

100.0

Formula. 

19.29 

2.80 

18.00 

8.70 

1.21 

5.17 

3.77 

.67 

40.39 

.0

100.0

Mg. per liter. 

0.363 

.459 

.158 

.664

1.644

Mg. per liter. 

0.317 

.046 

.296 

.143 

.020 

.085 

.062 

.011 

.664 

.0

1.644

Parts per million. 

7.4 

1.8 

6.1 

1.9 

.6 

4.0 

2.1 

.7 

40.0 

.0

28.0

72.2

10.0 

May 2-Oct. 19, 1907.

Wateree at Camden, S. C.

Percent. 

19.8 

23.4 

56.8

100.0

Per cent. 

21.62 

28.38 

9.91 

40.09

100.0

Formula. 

19.08 

2.54 

17.16 

10.97 

.25 

5.51 

4.03 

.37 

40.09 

.0

100.0

Mg. per liter. 

0.349 

.458 

.160 

.647

1.614

Mg. per liter. 

0.308 

.041 

.277 

.177 

.004 

.089 

.065 

.006 

.647 

.0

1.614

Porte per million. 

7.2 

1.6 

5.7 

2.3 

.11 

4.2 

2.2 

.38 

39.0 

.0

27.0

69.8

15.0 

May 10-Oct. 25, 1907.

Savannah at Augusta, Ga.

Per cent. 

23.0 

18.5 

58.5

100.0

Per cent. 

30.75 

19.25 

11.50 

38.50

100.0

Formula. 

26.32 

4.43 

15.31 

1.54 

2.40 

7.75 

2.95 

.80 

31.55 

6.95

100.0

g. per liter. 

0.500 

.313 

.187 

.626

1.626

Mg. per liter. 

0.428 

.072 

.249 

.025 

.039 

.126 

.048 

.013 

.513 

.113

1.626

Parts per million. 

9.9 

2.8 

5.1 

.4 

1.1 

6.0 

1.6 

.8 

31.0 

3.4

21.0

67.3

16.0 

May 12-Oct. 22, 1907.

Oconee at Dublin, Ga.

Per cent. 

25.6 

15.2 

59.2

100.0

Per cent. 

20.40 

29. 60 

12.80 

37.20

100.0

Formula. 

16.63 

3.77 

19.90 

8.20 

1.50 

7.15 

4.21 

1.44 

37. 20 

.0

100.0

Mg. per liter. 

0.369 

.534 

.231 

.672

1.806

Mg. per liter. 

0.300 

.069 

.359 

.148 

.027 

.129 

.076 

.026 

.672 

.0

1.806

Ports per million. 

6.9 

2.6 

7.2 

1.8 

.75 

6.2 

2.7 

1.6 

41.0 

.0

16.0

65.9

14.0 

May 15-Oct. 17, 1907.

Ocmulgee at Macon, Ga.

Per cent. 

26.2 

16.4 

57.4

100.0

Per cent. 

21.28 

28.72 

13.07 

36.93

100.0

Formula. 

18.31 

2.97 

17.24 

9.72 

1.76 

6.63 

5.62 

.82 

36. 93 

.0

100.0

Mg. per liter. 

0.337 

.455 

.207 

.585

1.584

Mg. per liter. 

0.290 

.047 

.273 

.154 

.028 

.105 

.089 

.013 

.585 

.0

1.584

Parts per million. 

6.8 

1.9 

5.7 

2.1 

.8 

4.9 

3.0 

.8 

35.0 

.0

26.0

79.2

14.0 

May 7-Oct. 21, 1907.

Properties.

Primary salinity. 

Primary alkalinity. 

Secondary alkalinity.

Reacting values.

Groups: 

Alkalies. 

Earths. 

Strong acida. 

Weak acids.

Concentration value.

Radicles: 

rNa. 

rK. 

rCa. 

rMg. 

rFe. 

rSO4. 

rCl. 

rN03 . 

r HCO3 . 

rCO3 .

Concentration value. 

Base analyses.

Radicles: 

Sodium (Na). 

Potassium (K). 

Calcium (Ca). 

Magnesium (Mg). 

Iron (Fe). 

Sulphate (SO4). 

Chloride (Cl). 

Nitrate (NO3). 

Bicarbonate (HCO3). 

Carbonate (CO3). 

Colloids: 

Silica (Si02).

Total dissolved 

solids. 

Number of composites. 

Dates.

95451° Bull. 479 11. (To face page 16.)
INTEEPEETATION" OF ANALYSES. 17

TABLE 3. Character of Coastal Plain river waters entering eastern Gulf of Mexico. 

' [Analysts, R. B. Dole, W. D. Collins, and Chase Palmer.)

Properties.

Primary salinity. . . . 

Primary alkalinity. . 

Secondary alkalinity

Reacting values. 

Groups:

Concentration 

value ..........

%

Radicles: 

Na. .................

K. ..................

Ca...................

Mg.. ................

Fe ..................

S04 ... ..............

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

NOs.................

HC0 3 .... ...........

Concentration 

value ..........

Base analyses.

Radicles: 

Sodium (Na).........

Magnesium (Mg) ..... 

Iron(Fe)............

Sulphate (SO.,).......

Chloride (Cl).........

Nitrate (N03 )........

Bicarbonate (HCO3 ) . 

Colloids: 

Silica (SiOj)..........

Total d i s s o 1 ved

N umber of composites. . . .

Oostanaula at 

Rome, Oa.

Per cent. 

10.2 

20.3 

69. 5

100. 0

Per 

cent. 

15.23 

34.77 

5.10 

44.90

100.0

Formula. 

13.94 

1.29 

21.81 

12.26 

.70 

3.15 

' 1.60 

.35 

44.90

100.0

Mg. per 

liter. 

0.391 

.893 

.131 

1.153

2.568

Mg. per 

liter. 

0.358 

.033 

.560 

.315 

.018 

.081 

.041 

.009 

1.153

2.568

Porte per million.

8.1 

1.4 

11.0 

3.6 

.5 

4.1 

1.6 

.56 

71.0

29.0

103.0 

12.0 

May 3-Oct. 28, 

1907.

Alabama at 

Selma, Ala.

Per cent. 

15.1 

10.6 

74.3

100. 0

Per 

cent. 

12.87 

37.13 

7.58 

42.42

100.0

Formula. 

10.98 

1.89 

25.86 

11.23 

.04 

4.01 

2.91 

.66 

42.42

LOO.O

Mg.per 

liter. 

0. 314 

.906 

.185 

1.035

2.440

Mg.per 

liter. 

0.208 

.046 

.631 

.274 

.001 

.098 

.071 

.016 

1.035

2.440

Parts per million.

6.4 

1.9 

13.0 

' 3.7 

.02 

4.5 

2.3 

1.0 

62.0

15.0

76.0 

4.0 

Sept. 8-Oct. 

17, 1907.

Cahaba at Birmingham, Ala.

Per cent. 

20.4 

4.6 

75.0

100.0

Per

cent. 

12.48 

37.52 

10.19 

39.81

100.0

Formula. 

10.34 

2.14 

26.-45 

10.57 

.50 

7.06 

2.71 

.42 

39.81

100.0

Mg.per 

liter. ' 

0.327 

.983 

.267 

1.043

2.620

Mg.per 

liter. 

0.271 

.056 

.693 

.277 

.013 

.185 

.071 

.011 

1.043

2.620

Parts per million.

6.3 

2.2 

14.0 

3.5 

.37 

8.8 

2.4 

.7 

62.0

16.0

89.0 

14.0 

May 5-Nov. 1, 

1907.

Tombigbeeat 

Epes, Ala.

Per cent. 

15. 4 

11.6 

73.0

100.0

Per 

cent. 

13.47 

36.53 

7.69 

42.31

100.0

Formula . 

11.57 

1.90 

32.68 

2.98 

.87 

4.55 

2.67 

.47 

42.31

100. 0

Mg. per 

liter. 

0.403 

1.093 

.230 

1.266

2.992

Mg.per 

liter. 

0.346 

.057 

.978 

.089 

.026 

.136 

.080 

.014 

1.266

2.992

Parts per million.

8.2 

2.4 

20.0 

1.5 

.75 

6.3 

2.6 

.9 

76.0

23.0

101.0 

14.0 

May 14-Oct.24, 

1907.

Pearl at Jackson,_Miss.

Per cent. 

28.1 

14.5 

57.4

100.0

Per

cent. 

21.32 

28.68 

14.08 

35.92

100.0

Formula. 

18.34 

2.98 

21.68 

6.36 

.64 

7.89 

5.43 

.76 

35.92

100. 0

Mg. per 

liter. 

0.365 

.491 

.241 

.615

1.712

Mg. per 

liter. 

0.314 

.051 

.371 

.109 

.011 

.135 

.093 

.013 

'.615

1.712

Parts per million.

7.3 

2.0 

7.6 

1.5 

.33 

6.4 

3.2 

.74 

37.0

14.0

59.0 

.15 

MaylO-Oct.19, 

1907.

During the period of the investigation the waters in general were 

soft and all were characterized by primary alkalinity, by which their 

softness is maintained. It is true that they contain dissolved mineral substances in small quantities, but the carbonates of the alkalies 

are perceptibly in excess of the amounts necessary to precipitate the 

other bases, so that permanent hardness is impossible. Here, then, 

is a large section of the country'favored with running waters whose 

incrusting constituents can not form hard scale in boilers and 

whose alkalies are sufficiently in excess to keep them soft. An 

95451° Bull. 479 11 2
18 GEOCHEMICAL INTERPRETATION OF WATER ANALYSES.

idea of the excessive alkalinity of these waters can be obtained by 

expressing their primary alkalinity in terms of sodium carbonate, 

as was done in'considering the waters of Lake Champlain (pp. 9-10). 

An estimate made in this way shows that the quantity of sodium, 

reckoned as sodium carbonate that is, that quantity of sodium in 

excess of all that can be regarded as equivalent to the sulphates, 

chlorides, and nitrates annually discharged by the rivers within the 

area extending from the James to and including the Pearl is enormous. The calculated quantity of sodium carbonate annually discharged from this area into the Atlantic Ocean and Gulf of Mexico is 

no less than 2,693,000 tons.

The quantity of alkaline material conveyed by these rivers to the 

sea is very large compared with the quantity produced commercially. 

In 1904, for example, 63 establishments in the United States produced 734,209 tons of sodas of aU kinds, namely, sodium carbonate, 

sodium bicarbonate, caustic soda, and sal soda; and 11,511 tons of 

soda were imported, a total of 754,720 tons, valued at $13,579,080.

RELATION OF WATER PROPERTIES TO GEOLOGIC FORMATIONS.

The result of a mineral analysis of the water of a river may serve 

as an index of the character of the geologic formations in its drainage 

basin, if the analyses are expressed, not in amounts of the radicles 

found in the water, but in terms showing the properties acquired by 

the water as it passes over or through the rocks.

The waters of Dan, Roanoke, James, and Shenandoah rivers, all 

originating among the Appalachian Mountains of western Virginia, 

develop markedly different qualities, as shown by the complete 

analyses given in Tables 1 and 2. The reaction properties of these 

waters, as deduced from analyses made of samples collected at points 

many miles distant from the sources of the rivers, are stated in 

percentage degrets in the following table:

Reaction properties of waters of Dan, Roanoke, James, and Shenandoah rivers.

Dan.

24.2 

.0 

15.3 

60.5

100.0

Roanoke.

15.1

.. .0 

8.7 

76.2

100.0

James.

18.3 

.0 

4.7 

77.0

100.0

Shenandoah.

10.5 

.2 

.0 

89.3

100.0

These figures show a progressive decline northward in the proportion of primary alkalinity, that is, permanent alkalinity, or such 

alkalinity as would be caused by alkaline carbonates and alkaline
INTERPRETATION OP ANALYSES. 19

bicarbonates (Na2C03 and NaHCO3 ), and in the water of Shenandoah 

River this property is entirely wanting. Equally striking is the progressive advance in secondary alkalinity that is, the property caused 

by alkaline earth bicarbonates, CaH2 (C03 ) 2 and MgH2 (CO3 ) 2 . This 

property coincides with temporary hardness.

Primary salinity that is, salinity caused by the sulphates and 

chlorides of the alkalies is also a conspicuous property of all these 

waters, ranging between 10 and 24 per cent of the total properties 

represented. The prominence of primary salinity among the properties of all these waters and its capacity for independent variation 

suggest that the cause of the progressive variations in the proportions 

of the two kinds of alkalinity may be found in the chemical nature 

of the rocks.

All these rivers, except the Dan, rise in the Appalachian Valley(, 

between the Blue Ridge and the Alleghenies, and start with water^ 

probably of the same general character. The headwaters of the Dan 

are not strictly within the Appalachian Valley, for the river rises on 

the eastern slope of the Blue Ridge. It flows eastward in a drainage 

basin comprising 2,700 square miles, which is practically confined to 

the granitic area of the Piedmont Plateau. The water was sampled for 

analysis at South Boston, Va., about 137 miles from the source of the 

river. The Dan is essentially a primary stream in that its waters 

derive their soluble substances from decomposed igneous rocks. Its 

water, like that of many other rivers that flow in areas of crystalline 

granitic rocks, is high in .primary alkalinity.

The Shenandoah, about 120 miles in length, rises in Augusta 

County, Va., about 25 miles north of Balcony Falls, on James River, 

flows northeastward in the valley west of the Blue Ridge, and discharges into the Potomac at Plarpers Ferry. The properties of its 

water are directly due to the soluble material received from siliceous 

limestones and shales. The entire valley is underlain by limestones, 

the shales outcropping at the base of the mountains. The virtual 

absence of permanent hardness (0.2 per cent) of the waters near the 

mouth of the river and the comparatively low primary salinity are 

characteristic of waters that traverse ancient limestone areas. Shenandoah Valley, lying well south of the region covered by glacial drift, 

occupies a geographical position favorable for observing the character that a river water acquires directly from the local formations. 

It is to be observed that the hardness of the Shenandoah River water 

is alkalinity; its alkalinity is hardness. Alkalinity and hardness are 

coincident in but few river waters.

Roanoke River rises in the Appalachian Valley in Montgomery 

County, Va., flows eastward about 50 miles, traversing the same limestone formations which are crossed by James River a few miles
20 GEOCHEMICAL INTERPRETATION OF WATER ANALYSES.

farther north and in which the Shenandoah remains through its 

entire course; it then cuts through the Blue Kidge and emerges on 

the granitic area of the Piedmont Plateau there to continue its eastward journey. The distance from the Blue Ridge to the sampling

FIGURE 1. Map showing geologic character of the drainage basins of Shenandoah, James, Roanoke, and 

Dan rivers. The shaded portion represents the area of crystalline rocks; the unsliaded portion, sedimentary rocks. Dash lines represent limits of drainage basins.

station at Randolph, Va., is a little less than 100 miles. The reaction 

properties of the river water at Randolph may be regarded as typical 

of a river water beginning in sedimentary formations and subsequently 

modified by the addition of water from a granitic area.
INTERPEETATION" OF ANALYSES. 21

In comparing the properties of this water with the properties of 

the waters of the adjacent streams, it should be remembered that 

the Koanoke flows in an area of sedimentary rocks for about one-third 

of its course and in an area of granitic rocks for about two-thirds of 

its course. The drainage area of Roanoke River is very unequally 

divided between the two geologic districts .through which it flows. 

The portion within the limestone area west of the Blue Ridge comprises about 583 square -miles, constituting only about one-fifth 

of the area of its entire basin; the portion on the Piedmont Plateau 

comprises about 3,080 square miles, or about four-fifths of the entire 

area from, which the water of the Roanoke has acquired its properties.

James River drains an area about equally divided between the 

Appalachian Valley and the Piedmont 1 Plateau, the upper part, lying 

west of the Blue Ridge, embracing 3 ; 030 square miles, and the Piedmont district about 3,800 square miles. Moreover, the James receives 

in the area of sedimentary formations contributions from several 

rivers of considerable size. Except for 'a few good analyses of waters 

in Rockbridge County, Va., made by A. W. White, 1 no information 

concerning the composition of these mountain streams is available. 

Three of White's analyses, interpreted according to the plan here 

adopted, show the general character of the waters received by the 

James just before it leaves the region of sedimentary rocks.

Analyses of waters flowing into James River. 

[Parts per million.]

1. Moore's Spring, North River drainage basin, near Lexington. Described as flowing from pure limestone. ' .

Solid residue (estimated)................................. 162

Silica (Si02 )............................................ 7. 2

2. South River, tributary to North River. Described as flowing along the dividing 

line between the Cambrian limestones and Cambrian sandstones.- 

Solid residue (estimated)................:................ 113

Silica (Si02 ). .......................................... 5. 5

3. North River, tributary to James River. Described as coming chiefly from, limestones, sandstones, and shales; sampled above junction with South River. 

Solid residue (estimated)................................. 85

Silica (Si02 ) ..........................................\ 5.1

Properties of reaction.

1

1.84

94.12

100.0

2

4. 76

7.38

87.86

100.0

3

4 98

10.14

84.88

100.0

i Composition of the waters of Rockbridge County, Va.; thesis for Washington and Lee University, 1906.
22 GEOCHEMICAL INTERPRETATION OF WATER ANALYSES.

These analyses afford excellent examples of the character of water 

from calcareous formations. The small proportion of silica reported as 

dissolved in the waters of James River valley west of the Blue Ridge 

is noteworthy, because of its marked contrast with the proportion of 

silica in the water of the James after the river has acquired primary 

alkalinity from the crystalline siliceous formations of the Piedmont 

Plateau.

This consideration of the chemical character of the waters of Dan, 

Roanoke, James, and Shenandoah rivers indicates that the results 

of water analyses may hereafter prove to be helpful guides in regional 

studies of streams.

SILICA IN RIVER WATERS. 

RELATION OF SILICA TO PRIMARY ALKALINITY.

A high proportion of silica in the mineral content of surface waters 

is thought by many observers to be normal only to small streams flowing from crystalline siliceous rocks, and especially to those streams 

near their sources; that is, if silica is a prominent constituent of the 

inorganic material dissolved in the water of a large stream, its presence 

must be attributed to some extraneous cause, such as tropical climatic 

conditions in the drainage basin or abundance of organic matter in 

the waters. The particular kind of organic matter that is supposed to 

facilitate the transportation of silica in water is that commonly known 

as azo-humic acids.' Owing to supposed basic properties acquired by 

the incorporation of nitrogenous material, these azo-humic acids are 

assumed to be capable of forming with hydrated silicic acid soluble 

compounds of unknown character, and thus to assist the water to 

carry along the silica with the rest of the "invisible load." Since 

high importance ha's been attached. to these assumed azo-humic 

acids in other geologic phenomena involving chemical processes, it 

seems not out of place here to state the circumstances under which 

the term azo-humic acids was introduced to chemical literature.

A report had been read before the French Academy of Sciences of 

certain elaborate experiments made by Friedel and Ladenburg l 

involving the synthesis of a compound of silicon analogous to propionic acid. To that report Paul Thtmard 2 offered remarks, in the 

course of which he alluded to some observations made by himself on 

the solution of silica in company with soil acids. He suggested that 

the solution of the silica might be due to nitrogen in the organic 

substances, but he cautiously refrained from making a definite statement concerning the nature of the products, merely promising to 

report in detail the results of subsequent experiments. So far as can 

be learned the promise was not fulfilled.

1 C. Friedel and A. Ladenburg,.Sur I'acide silico-propionique: Compt. Rend., vol. 20,1870, p. 1407.

2 P. Thfinard, Observations sur le memoire de M. Friedel: Idem, p. 1412.
INTERPRETATION OF ANALYSES. 23

The solubility of humic substances in water alone and in alkaline 

solutions was observed as long ago as 1826. Sprengel 1 was the first 

to recognize in these products of the soil a new class of substances, 

and his account of humus acid and its salts contains valuable information concerning the chemistry of these colloidal substances.

Directly bearing on the solubility of silicic acid in solutions of the 

humic substances is Sprengel's observation that silicic acid is precipitated in gelatinous form if solutions of this kind of organic material 

are added to a solution of potassium silicate. In view of these early 

observations by Sprengel concerning the action of humic solutions 

on silicates, and since The'nard himself seems to have considered as 

premature his announcement of the possible existence of azo-hurnic 

acids, it is unnecessary now to consider those vague substances as 

factors in the solution and portage of silica in river waters.

The solvent action of alkaline carbonates and hydroxides on silica

has long been known. Hydrated silicic acid is easily attacked and 

dissolved, even by dilute solutions of sodium carbonate, and dilute 

sodium carbonate is the reagent commonly used in the laboratory to 

separate silicic acid from quartz and refractory silicates. Unless 

precaution is taken against using an unduly strong solution of the 

alkaline carbonate, appreciable amounts of quartz are dissolved with 

the silicic acid and the separation of silicic acid from quartz is frustrated. Quartz is attacked and dissolved by prolonged digestion in 

even dilute alkaline carbonate solutions.2

SILICA IN THE WATERS OF THE PIEDMONT PLATEAU AND COASTAL PLAIN OF

THE GULF OF MEXICO.

As silica, contributes largely to the weight of the inorganic substances dissolved in the surface waters of the Piedmont Plateau and 

Coastal Plain area of the Southern States east of the Mississippi, the 

analyses of the waters of the rivers of this region afford exceptionally 

favorable data for a comparative study of the proportional amounts 

of silica with respect to primary alkalinity a property common to 

all the waters during the period of the investigation.

The waters of the rivers fall naturally into three groups, according 

to the geology of the drainage basins:

Group 1. Waters of streams coming from regions of sedimentary 

rocks and afterward traversing areas of crystalline rocks.

Group 2. Waters of streams practically confined to areas of crystalline rocks.

Group 3. Waters of streams practically confined to areas of sedimentary rocks and alluvial sands and clays.

1 Sprengel, C., Ueber Pflanzenhumus, Humussaure und humussaure Salze: Archiv fiir die gesammte 

Naturlehro (K. W. G. Kastner), Nurnberg, Bands, 1826,p. 126-220.

2 Lunge and Millberg, Zeitschrift fiir angewandte Chemie, 1897, pp. 390 and 425.
24 GEOCHEMICAL, INTEBPKETATION OF WATER ANALYSES.

Primary alkalinity and silica in Piedmont Plateau and Gulf Coastal Plain 'waters.

Group 1:

Group 2: 

Dan ..... ......................................................

Wateree. . ......................................................

Group 3:

Pearl. . .........................................................

Distance 

from 

source to 

sampling 

station.

Miles. 

276

162

137

72

225

216

168

176

62

447

17

192

120

Primary 

alkalinity.

Per cent. 

4.7

8.7

15.3

15.7

25.0

23.4

18.5

15.2

16.4

10.5

4.8

11.6

14.5

Si02 in 

inorganic 

substances.

Per cent. 

22.0

28.3

38.0

37.8

38.8

38.7

31.2

24.3

32.8

19.2

18.9

22.3

23.0

The acquisition of primary alkalinity by James, Roanoke, and Dan 

rivers has. already been considered in discussing their environment. 

Equally striking is the proportional increase of silica in the inorganic 

material contained in their waters. The advance and decline of 

silica concomitant with the rise and fall in primary alkalinity in all 

the waters of the Atlantic coast rivers point to a continuance of the. 

correlation of silica with the primary alkalinity of the river waters, 

just as silica is associated with the alkalies at the beginning. Although 

subject to various disturbing influences, the mixed waters of the Gulf 

Coastal Plain rivers show a similar relation between silica and primary 

alkalinity. A high proportion of silica in the mineral content of these 

river waters is easily accounted for, because the acidic radicles of the 

alkaline carbonates, always present in waters of this character, tend 

constantly to form the sparingly soluble carbonates of the other positive radicles of the solutes, while the soluble bases of the alkalies from 

the hydrolyzed alkaline carbonates produce alkaline solutions naturally favorable to the retention of dissolved silica.

OTHER RIVERS DRAINING AREAS OF CRYSTALLINE ROCKS.

OTTAWA KIVER.

The Ottawa is the largest tributary of the St. Lawrence. It rises 

in latitude 47° 53' north, longitude 75° 35' west, and discharges into 

St. Lawrence River near Montreal. It is 730 miles long and drains 

an area comprising more than 56,000 square miles. According to 

R. A. Daly, geologist of the International Boundary Commission, the 

Ottawa basin is larger than any other river basin known to be underlain by pre-Cambrian formations. 1

'Daily, R. A., First calcareous fossils and the evolution of the limestones: Bull. Geol. Soc. America, 

vol. 20, 1909, pp. 153-170.
INTERPRETATION OF ANALYSES. 25

The composition of the water of Ottawa River at high stages has 

been recently determined by Frank T. Shutt and A. Gordon Spencer.1 

The water was collected in July, 1907, from the main stream above 

Chaudiere Falls.

The interpretation of an analysis of Ottawa River water made by T. 

Sterry Hunt at a much earlier date shows that before the snows begin 

to melt the proportion of primary alkalinity to the other properties 

of the water is much higher than it appears to be during the summer 

floods. The water for Hunt's analysis was collected in March, 1854, 

at St. Anne's Lock, near Montreal.2

Thesa analyses are interpreted in the following table:

Character cf Ottawa River water interpreted from analyses.

Properties:

Reacting values of groups:

\Veak acids

Reacting values of radicles: 

r Na. ..............................:.............................

r K. .............................................................

rCa.............................................................

rMg........... :................................................

rC03 ...... ......................................................

r P 04 ...........................................................

r§0<.......... ..................................................

rCl............................................ ..................

Colloids:

SiO, ............................................................ \ito3 . ....................... ...................................

Analysis 

by Shutt 

and Spencer.

Per cent. 

14.7

1.8

83.5

100.0

8.23

7.35

42.05

100.0

6.77

1.40

28.04

iq 70

41.88

.77

G.O i t^

100.0

Mg. per 

liter.

35.1

7.1

.5

.7

1.034

Analysis 

by Hunt.

Per cent. 

8.3

9.8

81.9

100.0

9 ni

40.97

4.13

45. 87

100.0

G.C7

2. 30

32.33

8.64

45.77

2.02

1.51

100.0

Mg. per 

liter.

00.0

21.0

1.528

Average.

Per cent. 

11.5

5.8

82.7

100.0

8. 03

41.37

5.74

. 44. 20

100.0

Attention is called to the high proportion of silica in the mineral 

content of the water at the time of Hunt's analysis and also to the 

striking differences in the chemical character of the solutions with 

respect to the proportions of properties on the two occasions when 

the water of Ottawa River was investigated.

Trans. Royal Soc. Canada, 3d series, vol. 2, 1909, p. 175. 

Hunt, T. S., Canada Geol. Survey Rept., 1803, p. 565.
26 GEOCHEMICAL INTERPRETATION OF WATER ANALYSES.

MAHANUDDY-RIVER, INDIA, AND URUGUAY RIVER, BRAZIL.

Mahanuddy River, of India, is selected to illustrate the chemical 

character of a river water draining a sparsely settled area. According 

to Edward Nicholson, the geologic formations in its drainage basin 

are made up chiefly of trap, basalt, and gneiss, and the soils formed 

by the decomposition of those rocks. The river is about. 500 miles 

long, and empties into the Bay of Bengal. The drainage basin of 

Mahanuddy River lies wholly within the Tropics. The analysis 

interpreted was made by Nicholson 1 on a sample collected at Cuttack, India, about 60 miles above the mouth of the river.

Uruguay River rises in the mountains of Santa Catharina in southern Brazil, flows first westward and then southward, and empties 

into the La Plata near Buenos Aires. The Uruguay is about 1,000 

miles long. Its water is said to be clear and free from sediment, 

except during seasons of flood. The high primary alkalinity of the 

water and the high proportion of silica in the dissolved inorganic 

material are noteworthy features of .this great stream of the South 

Temperate Zone. The analysis selected for interpretation was made 

by Kyle, 2 who was for many years water expert in Argentina.

The character of Mahanuddy and Uruguay rivers, as interpreted 

from the analyses, is shown in the following table:

Character of Mahanuddy and Uruguay rivers.

Properties:

Reacting values of groups:

Reacting values of radicles:

rK.... ..................................................................

r Ca. ................................:.................................-..

rFe..................... .................................................

rC08 ... ..................................................................

rPO<..... ...............................................................

rS04 .... ................................................................

rCL. ....................................................................

rN03 . ...................................................................

Mahanuddy 

(Nicholson, 

analyst).

13.7

6.0

79 7

100.0

10.16

39.84

6.85

43.15

100.0

8.69

1.47

26.54

13.02

.28

42.41

.78

. 1.97

4.10

ioo.o

Uruguay 

(Kyle, 

analyst).

18.2

6 9

74 9

100.0

19 ^1

37.46

9.08

40.92

100.0

8.57

3.97

' 25. 32

12. 14

40. 92

3.84

.77

4.47

100.0

1 Jour. Chem. Soc., 1873, p. 229.

2 Kyle, J. J. J., Chem. News, vol. 38,1878, p. 28.
INTERPRETATION OF ANALYSES.

Character of Mahanuddy and Uruguay rivers Continued.

27

Colloids: 

SiOa ............... .................................:....................

Concentration value ."........................................................

Mg. per liter.

80.0

27.8

2.438

Mg, per liter.

 <Q s

18.5

0.782

Mr. Kyle's official duties in. connection with choosing a suitable 

water supply for Buenos Aires afforded him unusual opportunity to 

learn the character and quality of many rivers in the surrounding 

territory. A subsequent report by Kyle shows that primary alkalinity is not confined to Uruguay River but is characteristic of many 

rivers in the same drainage area.

Kyle's description of the appearance of Uruguay River, of its purity, 

and of the siliceous character of its water deserves to be quoted:

The water of the river Uruguay is in some respects very remarkable. It is probably 

one of the purest river waters in the world, containing rather less than 4 parts of solid 

matter per 100,000. It is almost free from chlorides; the determination of chlorine, 

made with every possible care, gave rather less than one-fourth of a milligram per liter, 

and this, be it remembered, at a distance of say 500 miles from its source.

Still more noteworthy, in my opinion, is the fact that "about 46 per cent of the total 

solid matter consists df soluble silica, not suspended as in the other two rivers, A 

8inall proportion exists probably as alkaline silicate, but the greater part is undoubtedly 

present as hydrated silicic acid. In this circumstance may be found an explanation 

of the petrifying properties attributed to the water of the Uruguay. On one occasion 

a cart wheel was fished up from its bed completely converted into stone. A considerable export trade in agates is carried.on by the inhabitants on the Uruguayan 

shores of this great river, and the stones from the Uruguay are; I believe, those most 

esteemed by European lapidaries. The free silicic acid dissolved by this river among 

the mountains of Santa Catharina, in'' Brazil, is probably the raw material out of 

which are elaborated the agate mortars so invaluable to every analytical chemist.

PERSISTENCE OF SILICA IN RIVER WATERS.

The percentage values of the primary and secondary alkalinity of 

the Ottawa, Mahanuddy, and Uruguay River waters as obtained from 

the character formulas are repeated here for comparison.

Alkalinity of Ottawa, Mahanuddy, and Uruguay rivers.

Ottawa 

(average).

5.8

82.7

Mahanuddy.

6.6

79.7

Uruguay.

6.9

74 9

The percentage of silica in the dissolved inorganic material is, for 

Ottawa River, 29; for Mahanuddy River, 32; and for Uruguay 

River, 46. -

Kyle's results show that the high proportion of silica in the 

inorganic material of Uruguay River can not be correlated with dis-
28 GEOCHEMICAL, INTERPRETATION OP WATER, ANALYSES.

solved organic matter but may, on the contrary, be due, in part at 

least, to the absence of organic matter. The Uruguay, in latitude 27° 

to 36° south, occupies in the Southern Hemisphere a position closely 

corresponding to that of the Piedmont Plateau and Coastal Plain area, 

between latitudes 30° and 38° north. Mahanudcly River is tropical; 

the Ottawa flows in the far north. The waters of all these rivers 

are primary-alkaline, and, irrespective of climate, all of them show a 

tendency favorable to the retention of silica. Their story corroborates the story told by the rivers of our own land. The high proportion of silica, moreover, in the mineral content of the waters of 

these three great rivers, draining granitic areas in widely separated 

parts of the earth, indicates that as a prominent constituent of the 

dissolved material, silica in river waters is not necessarily confined 

to the waters near the sources of the streams. On the contrary, the 

evidence tends to show that silica may constitute a large part of the 

material in the water of rivers at remote distances from, their sources, 

if the conditions are such as to maintain the primary alkalinity of 

their waters.

The actual state of silica in highly dilute solution may not be perfectly understood and these observations do not bear directly on its 

physical condition, but it is hoped that they will show the propriety of 

interpreting mineral analyses of water according to modern chemical 

principles.

THE WATER OF MISSISSIPPI RIVER.

The interpretation of a series of analyses of the water of Mississippi 

River made by chemists of the United States Geological Survey 

reveals the changes in the character of the water of a great river at 

different points. , As shown in Table 4, the water of the Mississippi 

at Minneapolis is very simple in character, being distinguished only 

by secondary alkalinity, primary salinity, and very low secondary 

salinity or permanent hardness. In these qualities the water of 

the Mississippi resembles the water of the Shenandoah at its mouth. 

At Moline, 111., permanent hardness appears definitely among the 

properties of the Mississippi water, although it occupies a very subordinate position. It should "be observed that the proportion of 

primary salinity in the water of the upper Mississippi remains practically constant for the entire distance between Minneapolis, Minn., 

and Quincy, 111., thus constituting an important feature of the 

water of this part of the river. At Chester, 111., the character of the 

water appears to be greatly changed, for the analyses indicate that the 

proportion of primary salinity is much increased and the proportion 

of permanent hardness that is, secondary salinity is more than 

doubled.
TABLE 4. Character of water of Mississippi and Missouri rivers.

Properties.

Reacting values. 

Groups:

Earths.................

Concentration value.

Radicles: 

rNa........... ........

rK....... ............

r Ca..................

r IVfof

rS04 ......... .........

rCl...................

rN03 ..................

rHCO3 ...............

rC03 .......... .......

Concentration value. 

Base analyses.

Radicles: 

Sodium (Na) ..........

Potassium (K) .........

Calcium (Ca) ..........

Magnesium (Mg) .......

Iron (Fo). .............

Sulphate (SOj ........

Chloride (01)...........

Nitrate (NO3 ). ........

Bicarbonate (HCO3 ) . . . 

Carbonate (C03 ) . .......

Colloids: 

Silica (SiOV>.. .........

Alumina (A1203 )

Mississippi above mouth of Missouri.

At Minneapolis, Mirm. o &

Per cent. 

12.1 

.6 

87.3

100.0

Per cent. 

6.04 

43.96 

6.36 

43.64

100.0

Formula. 

} 6.04

28.01 

15.94 

.02 

5.32 

.69 

.35 

43.64 

.0

100.0

Mg. pir liter. 

0.428 

3.117 

.451 

3.094

7.090

Mg. per liter. 

0.428

1.985 

1.130 

.002 

.377 

.049 

.025 

3.094 

.0

7.090

Parts per million. 

} 10.0

40.0 

14.0 

.07 

18.0 

1.6 

1.4 

188.0 

.0

15.0

Iron (Fe,03)............ .....................

Total dissolved solids . 

Number of composites. .....

Dates.....................

200.0

35 

Sept. 10, 1906-Sept. 

11, 1907.

At Moline, HI. o c

Per cent. 

13.8 

6.6 

79.6

100.0

Per cent. 

6.86 

43.14 

10.18 

39.82

100.0

Formula. 

6.86

26.14 

16.81 

.19 

8.01 

1.72 

.45 

39.82 

.0

100.0

Mg. per liter. 

0.430 

2.705 

.638 

2.497

, 6.270

Mg. per liter. 

0.430

1.639 

1.054 

.012 

.502 

.108 

.028 

2.497 

.0

6.270

Parts per million. 

10.0

33.0 

13.0 

.39 

24.0 

3.7 

1.8 

152.0 

.0

16.0

179.0

18 

Feb. 1, 1906-July 

31, 1907.

At Quincy, I1L o c

Per cent. 

13.2 

6.0 

80.8

100.0

Per cent. 

6.60 

43.40 

9.62 

40.38

100.0

Formula. 

6.60

25.02 

18.17 

.21 

7.33 

1.80 

.49 

40.38 

.0

Mg. per liter. 

0.471 

3.096 

.686 

2.881

7.134

Mg. per liter. 

0.471

1.785 

1.296 

.015 

.523 

.128 

.035 

2.881 

.0

100. 0 7. 134

Parts per million. 

11.0

36.0 

16.0 

.46 

25.0 

4.4 

2.2 

175.0 

.0

18.0

203.0

36 

Apr. 1, 1906-July 

31, 1907.

Mississippi below mouth of Missouri.

At Chester, El. o '

Per cent. 

20.6 

13.7 

65.7

100.0

Per cent. 

10.29 

39.71 

17.14 

32.86

100.0

Formula. 

10.29

24.90 

14.66 

.15 

13.38 

3.24 

.52 

32.86 

.0

100.0

Mg. per liter. 

0.900 

3. 472 ' 

1.499 

2. 873

8.744

Mg. per liter. 

0.900

2.177 

1.282 

.013 

1.170 

.283 

.046 

2.873 

.0

8.744

Parts per million. 

21.0

44.0 

16.0 

.39 

56.0 

9.8 

2.7 

174.0 

.0

22.0

269.0

32 

Aug. 1, 1906-July 

31, 1907.

At Memphis, Term, o <J

Per cent. 

21.9 

8.4 

69.7

100.0

Per cent. 

10.96 

39.04 

15.16 

34.84

100.0

Formula. 

( 9.86 

i 1.10 

26.35 

12.54 

.10 

10.54 

4.55 

.07 

32.10 

2.74

100.0

Mg. per liter. 

0.761 

2.713 

1.053 

2.421

6.948

Mg. per liter. 

0.685 

.076 

1.831 

.875 

.007 

.732 

.316 

.005 

2.231 

.190

6.948

Parts per million. 

( 16.0 

i 3.0 

37.0 

11.0 

.3 

35.0 

11.0 

.33 

135.0 

5.7

19.0

209.0

11 

Sept. 9, 1907-Jan. 

1, 1908.

At New Orleans, La. & «

Per cent. 

19.9 

11.3 

68.8

100.0

Per cent. 

9.96 

40.04 

15.61 

34.39

100.0

Formula. 

\ 9.96

28.66 

11.38

9.45 

5.40 

.76 

34, 39 

.0

100.0

Mg. per liter. 

0.540 

2.170 

.846 

1.864

5.420

Mg. per liter. 

0.540

1.553 

.617

.512 

.293 

.041 

1.864 

.0

5.420

Porto per million. 

} 13.0

32.0

8.4

24.0 

9.7 

2.5 

111.0 

.0

11.0

}

166.0

52 

Apr. 29, 1905-Apr. 

28. 1906.

Missouri at mouth.

At Ruegg, Mo. o &

Per cent. 

27.8 

18.8 

53.4

100.0

Per cent. 

13.89 

36.11 

23.30 

26.70

100.0

Formula. 

f 12. 37 

\ 1.52 

23.84 

12.11 

.16 

19.80 

3.08 

.42 

26.70 

.0

100.0

Mg. per liter. 

1.517 

3.941 

2.544 

2.914

10. 916

Mg. per liter. 

1.351 

.166 

2.600 

1.323 

.018 

2.162 

.336 

.046 

2.914 

.0

10. 916

Ports per million. 

f 31.0 

1 6.5 

52.0 

16.0 

.51 

104.0 

12.0 

2.9 

178.0 

.0

29.0

r........ ............ I....................

346.0

36 

Sept. 27, 1906-Oct. 

6, 1907.

Properties.

Primary salinity. 

Secondary salinity. 

Secondary alkalinity.

Reading values.

Groups: 

Alkalies. 

Earths. 

Strong acids. 

Weak acids.

Concentration value.

Radicles: 

rNa. 

rK. 

r Ca. 

r Mg. 

r Fe. 

rSO4. 

rCl. 

rN03 . 

r HCO3 . 

rCO3 .

Concentration value. 

Base analyses.

Radicles: 

Sodium (Na). 

Potassium (K). 

Calcium (Ca). 

Magnesium (Mg). 

Iron (Fe). 

Sulphate (SO4). 

Chloride (Cl). 

Nitrate (N03 ). 

Bicarbonate (HC03 ). 

Carbonate (CO3). 

Colloids: 

Silica (Si02). 

Alumina (A12O3 ). 

Iron (Fe203).

Total dissolved 

solids. 

Number of composites. 

Dates.

a Averages of analyses of composite samples each composite consisting of 10 daily collections. 

6 Reported in Water-Supply Paper U. S. Geol. Survey No. 236,1909.

c Reported with descriptions and details by W. D. Collins; Quality of surface waters of Illinois: WaterSupply Paper U. S. Geol. Survey No. 239,1910.

95451° Bull. 479 11. (To face page 28.)

d Analyses by R. B. Dole, W. D. Collins, and Chase Palmer.

« Average of analyses of composite samples, each composite consisting of 7 daily collections.
INTERPRETATION OF ANALYSES. 29

The proportional variation that has taken place in the properties 

of the river water between Quincy and Chester is the same in kind as 

the change commonly, observed in the properties of a chemical 

reagent if the proportions of the salts dissolved in it are changed. 

The principal cause of the change in the proportions of properties 

observed in the water of the Mississippi at Chester is the highly saline 

water poured by the Missouri into the Mississippi at a point between 

Quincy and Chester. From Chester to New Orleans the river water 

appears to undergo no permanent change in general character. In 

the water at Memphis the analyses indicate temporary reduction in 

secondary salinity, probably due in large measure to water brought 

in by Ohio River. Additional contributions of saline waters from 

the West, received through Arkansas and Red rivers, suffice to 

maintain in the water of the lower Mississippi that high proportion 

of salinity first derived midway in its course from Missouri River.

The changes in the character of the waters of the upper and lower 

Mississippi show the manner in which salinity may be developed in 

the water of a river whose drainage basin contains large areas of 

sedimentary rocks.

THE WATER OF THE GREAT LAKES AND ST. LAWRENCE RIVER.

The changes in the character of the water of the St. Lawrence 

River system occur in somewhat different order from that observed 

in the course of the Mississippi, and may be traced through the Great 

Lakes by interpretations of recent analyses by Dole and Roberts.1 

As Lake Superior occupies a higher and more westerly position than 

the other lakes, it will be considered first.

The interpretation presented in Table 5 indicates that the water 

of Lake Superior the largest body of fresh water on the globe is 

distinguished by primary alkalinity. The water of Lake Michigan 

is very different from that of Lake Superior, as the samples show 

properties characteristic of a water coming from a region of sedimentary rocks, and a distinct resemblance is shown between the 

water of Lake Michigan and that in the lower part of Lake Huron.

At Buffalo, N. Y., the total primary and secondary salinity of-the 

water of Lake Erie shows an increase of 9 per cent over the proportion of the same properties in the water of Lake Huron. That this 

conspicuous change in the character of the water of the Great Lakes 

is caused by local conditions may be inferred from the fact that no 

further change of properties in the same direction is observable in the 

water at Ogdensburg, N. Y., even after its long journey through Lake 

Ontario. The character formula of Lake Erie water discloses at once 

the fact that the remarkable increment in the proportion of salinity 

in the lake water is caused by chlorides and sulphates and suggests

i Water-Supply Paper U. S. Geol. Survey No. 236.
30 GEOCHEMICAL INTERPRETATION OF WATER ANALYSES.

the advent of brines, known to abound among the rocks in the 

drainage area of Lake Erie. One of the most important streams 

draining this area is the Maumee, whose water, where it enters the 

upper end of Lake Erie, closely approaches a brine in character. 

Since the character formula is distinctively a rational expression, the 

reacting ratios of the radicles in the formula can be obtained directly 

from their percentage values. In the formula it will thus be seen 

that the value of the chlorides exceeds the total value of the 

alkalies. This relation is exceptional in river waters and may be 

charged directly to the waste brines that flow into Maumee River 

from the numerous oil wells of the district. The excess of chlorides 

of the alkaline earths over alkaline chlorides is not peculiar to the 

brines of Ohio. In the salt water already mentioned as occurring at 

Highland, 111., a similar condition may be seen. In localities where 

salt is produced as a commercial article from Ohio brines, the excess 

of alkaline earth chlorides is sufficient to warrant the separate manufacture of calcium chloride, and this compound is reported to be a 

very profitable by-product of the salt industry.

From the values in the character formula the relative reacting 

values of the different radicles may be traced. The ratios of the 

reacting values of sodium and chlorine in the Great Lakes, chlorine 

being 1, are shown below:

Sodium in Great Lakes. 

Lake Superior.................................................. 4. 0

Lake Michigan..................................................-2. 7

Lake Huron..................................................... 2. 4

Lake Erie....................................................... 1.2

Lake Ontario.................................................... 1.3.

The ratio for the water of Lake Ontario is taken from the analysis

of the St. Lawrence River water at Ogdensburg, N. Y.

In the Mississippi River water a similar progressive advance of 

chlorine on sodium is also observed. The ratios are shown below, 

chlorine being uni,ty.

Sodium in Mississippi River.

Minneapolis.................................................... 8.8

Moline............................-............................... 4.0

Quincy......................................................... 3. 7

Chester......................................................... 3.2

Memphis........................................................ 2.4

New Orleans.................................................... 1. 8

The progressive advance of chlorine on sodium in the water of the 

Mississippi and of the Lakes shows lines along which flowing water 

develops salinity as it traverses sedimentary rocks.

As the water from Lake Ontario enters the channel of St. Lawrence 

River it becomes subject to conditions prevailing in a region of ancient 

crystalline rocks. The change in character resulting from change
TABLE 5. Character of water of St. Lawrence basin.

Properties. 

Primary salinity. .........

Reacting values.

Groups: 

Alkalies. .............

Earths. ..............

Concentration value .

Radicles: 

rNa. ................

rK...... .............

rCa. .................

rMg..................

rFe. ..................

i S0t.. ......... .......

rCl...................

rN03 -. ..............

rHC03 . ..............

rC03 .................

Concentration value. 

Base analyses.

Radicles: 

Sodium (Na) ..........

Potassium (K) .........

Calcium (Ca). . ........

Magnesium (Mg) .......

Iron (Fe). ............'.

Sulphate (SO4)........

Chloride (Cl). ........

Nitrate (NO3 ) .........

Bicarbonate (HC03 ). . . 

Carbonate (CO3 ) ......

Colloids: 

Silica (Si02). .........

Total dissolved solids.

Lake Superior, Sault Ste. 

Marie, Mich.c

Percent. 

8.6 

.0 

4.6 

86.8

100.0

Per cent. 

6.00 

43.40 

4.29 

45.71

100.0

Formula. 

j 6.60

31.52 

11.77 

.11 

2.22 

1.67 

.40 

45.71 

.0

100.0

Mg. per liter. 

0.134 

.881 

.087 

.928

2.030

Mg. per liter. 

0.134

.640 

.239 

.002 

.045 

.034 

.008 

.928

2.030

Parts per million. 

} 3.2

13.0 

3.1 

.06 

2.1 

1.1 

.5 

56.0 

.0

7.4

60.0 

11.0 

Sept., 1906-Aug., 

1907.

Lake Michigan, St. Ignace, 

Mich.a

Percent. 

9.4 

1.3 

.0 

89.3

100.0

Per cent. 

4.70 

45.30 

5.36 

44.64

100.0

Formula. 

4.70

29.84 

15.44 

.02 

3.50 

1.73 

.13 

42.35 

2.29

100.0

Mg. per liter. 

0.204 

1.966 

.227 

1.943

4.340

Mg. per liter. 

0.204

1.295 

.670 

.001 

.152 

.075 

.006 

1.838 

.099

4.340

Parts per million. 

4.7

26.0 

8.2 

.04 

7.2 

2.7 

.3 

112.0 

2.9

10.0

118.0 

11.0

Sept., 1906-Aug., 

1907.

Lake Huron, Port Huron, 

Mich.o

Per cent. 

9.6 

1.6 

.0 

88.8

100.0

Per cent. 

4.79 

45.21 

5.58 

44.42

100.0

Formula. 

4.79

30.77 

14.40 

.04 

3.45 

1.97 

.16 

42.86 

1.56

100.0

Mg. per liter. 

0.185 

1.742 

.215 

1.712

3.854

Mg. per liter. 

0.185

1.186 

.555 

.001 

.133 

.076 

.006 

1.652 

.060

3.854

Parts per million. 

4.4

24.0 

7.0 

.04 

6.2 

2.6 

.4 

100.0 

1.8

12.0

108.0 

9.0 

Sept., 1906-June, 

1907.

Lake Erie, Buffalo, N. Y.o

Per cent. 

11.5 

9.2 

.0 

79.3

100.0

Per cent. 

5.77 

44.23 

10.34 

39.66

100.0

Formula. 

5.77

31.34 

12.83 

.06 

5.41 

4.88 

.08 

37.57 

2.06

100.0

Mg. per liter. 

0.286 

2.193 

.514 

1.965

4.958

Mg. per liter. 

0.286

1.554 

.636 

.003 

.268 

.242 

.004 

1.863 

.102

4.958

Parts per million. 

6.5

31.0 

7.6 

.07 

13.0 

8.7 

.3 

114.0 

3.1

5.9

133.0 

11.0 

Sept., 1906-Aug., 

1907.

St. Lawrence River, 

Ogdensburg, N. Y.o

Per cent. 

11.4 

7.5 

.0 

81.1

100.0

Per cent. 

5.70 

44.30 

9.42 

40.58

100.0

Formula. 

5.70

31.82 

12.44 

.04 

5.05 

4.37 

.08 

38.57 

1.96

100.0

Mg. per liter. 

0.281 

2.169 

.464 

1.986

4.900

Mg. per liter. 

0.281

1.558 

.609 

.002 

.247 

.213 

.004 

1.890 

.096

4.900

Parts per million. 

6.3

31.0 

7.2 

.05 

12.0 

7.7 

.3 

116.0 

2.9

6.6

134.0 

11.0 

Sept., 1906-Aug., 

1907.

St. Lawrence River, 

south side, opposite 

Montreal.*

Per cent. 

11.8 

4.8 

.0 

83.4

100.0

Per cent. 

5.91 

44.09 

8.30 

41.70

100.0

Formula. 

5.91

29.28 

14.81

6.31 

1.99

Mg. per liter. 

0.312 

2.326 

.438 

2.200

5.276

Mg. per liter. 

0.312

1.545 

.781

.333 

.105

41. 70 2. 200

100.0 5.276

Parts per million. 

7.20

30.6 

9.5

16.5 

3.6

65.7 

14.8

147.9

Collected Nov. 24, 

1884.

St. Lawrence River, 

Pointe des Cascades, 

opposite Vaudreuil.c

Per cent. 

9.6 

.0

.7 

89.7

100.0

Per cent. 

5.16 

44.84 

4.81 

45.19

100.0

Formula. 

/ 4.53 

1 .63 

32.52 

12.32

3.51 

1.30

45.19

100.0

Mg. per liter. 

0.254 

2.209 

.237 

2.226

4.926

Mg. per liter. 

0.223 

.031 

1.602 

.607

.173 

.064

2.226

4.926

Parts per million. 

( 5.1 

I 1-2 

32.0 

7.2

8.3 

2.3

67.0 

37.0

160.1

Collected Mar., 1854.

Properties.

Primary salinity. 

Secondary salinity. 

Primary alkalinity. 

Secondary alkalinity.

Reacting values.

Groups: 

Alkalies. 

Earths. 

Strong acids. 

Weak acids.

Concentration value.

Radicles: 

rNa. 

rZ. 

rCa. 

rMg. 

rFe. 

rSO4 . 

rCl. 

rN03 . 

r HC03 . 

rC03 .

Concentration value. 

Base analyses.

Radicles: 

Sodium (Na). 

Potassium (K). 

Calcium (Ca). 

Magnesium (Mg). 

Iron (Fe). 

Sulphate (SO4). 

Chloride (Cl). 

Nitrate (NO3V. 

Bicarbonate ?HC03) 

Carbonate (C03). 

Colloids: 

Silica (Si02).

Total dissolved solids. 

Number of analyses. 

Collections monthly.

o Dole and Roberts, analysts. 

95451° Bull. 479 11. (To face page 30.)

6 Norman Tate, analyst. c T. Sterry Hunt, analyst, Geol. Survey, Canada, Rept. for 1863, p. 565.
INTERPRETATION OF ANALYSES. 31

in environment appears in the interpretation of analyses of the water 

at Ogdensburg, N. Y. (Table 5). Between Buffalo, on Lake Erie, and 

Ogdensburg no appreciable change appears to have occurred in the 

amount of soluble material contained.in the water, but a decided 

reduction is evident in the concentration value of the solution. The 

change in this value, coincident with a change in the proportions of the 

properties of the solution, while the weight of the dissolved salts 

remains practically constant, should not be overlooked. That this 

incipient reversion from salinity to alkalinity is due to environment 

is manifest. It is only necessary to recall the fact that directly below 

the point at which samples of the St. Lawrence water were collected 

Oswegatchie River is adding primary-alkaline water, brought from 

the Adirondacks, to reduce the secondary salinity of the St. Lawrence waters, which reached, its maximum at Buffalo.

For judging the chemical character of the St. Lawrence River water 

below Ogdensburg the available data are very limited. An analysis 

made in 1884 1 of the river water collected on the south side of the 

river opposite Montreal shows a still further reduction in the proportion of secondary salinity, and is in perfect accord with the inference 

that might follow' the consideration of what is known to be going on 

at the upper end of the St. Lawrence River channel.

Even more striking is a very early analysis of the river water made 

by T. Sterry Hunt. The water was collected in the main St. Lawrence just above the most westerly outlet of the Ottawa, in the same 

month and year in which the sample was taken for the analysis of the 

Ottawa River water that has already been considered. The complete 

reversion of secondary salinity to alkalinity indicated at this point 

should not be taken too seriously, for a temporary eddying of the 

waters may have caused admixture of the river water with a primary 

water. At all events the tendency of the St. Lawrence water to 

revert to a primary-alkaline water is abundantly shown. Below the 

city of Montreal the Ottawa enters the St. Lawrence by two additional channels, and about 45 miles below Montreal the Richelieu is 

adding its alkaline waters brought from Lake Champlain. With 

the data at hand it is impossible to state with certainty how far the 

work of restoration brings back the character of the water of the 

St. Lawrence to the character of the water of Lake Superior. In the 

regional study of waters there is much to be done, and great profit 

is to be expected from work in this field.

CONCLUSION.

In this preliminary consideration of water analyses sufficient ground 

has been covered to justify the conclusion that natural water may 

be definitely characterized if the salts dissolved in it are recognized 

not as a load but as a chemical systeln of balanced values.

i Analysis by Nprman Tate; published by T. Mellard RQftde in. Evplutfpq pfearth structure, 1903, p. 265.

o