New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1844-05-28
vCL. Nv. NO. "a.

We. nv. NO. e A.
who advanced various hypothcses to the seeds Of
CRYSTALS, their generation, &c. But, excepting
Iluvcens, who, a very recondIic treatise first de-
ye!oped the Ubly.rciractiag nature ui Iceland
spar and inferred that elementary particles were
spheroids 10 account for this peculiar .eracIiur,
none made any real Improvements on the specu!a-
tons OF their predecessors.
With NicoluGs Steno, toward the latter part Of
the l1tn century, commences Il new This
thor examined ninuicy The different forms OF &c, c.
raj minerals and accurately described them. lie
also first Gcduccd the imporiGnt principle IN Crystal
lngraphv afterwards redscovered,.tha aitk0vg h the
G,ceS Of crystals are sasctto frequent rarintiOnS
Of form, thar i.ciinaftOnS are CONSTANT In the
commencement ot the 18Th century, Guelmini
published on the cr! solicitations Of the sails, aid
advanced auoincr Triucipic equally fundamental.
that cic0rnge IA crystals IF he same substaSce
yteLo's c0RShUtty tie same torlaS. Gulieniin! WAS
led lay his observations 10 lie conclusions rs
the Able ii0tiy, namely that the elementary
puSculeS o., bodies POSSESSED those simple forms
winch ma, be obtained from crystals b, cleavage.
He neglected. however, TO extend his Investigations
on this subject amd left 10 Rome de Isle and Hatiy
The honor OF founding The science Of Crystal0-
graPny
Mr.. DANA then enters into long and minute
examination Of the theories OF LinnGus, J. Wood
ward, VI. Bolasc, Bergman, Werner, the Chcm
cal theory, &c. &c. all Of which he shows 10
be ialiacious. We now, Of cDuTGc GENE 10 his
own theory. 1t IS too much elaborated and cut
up into chapters, sections and paragraphs to he
copied. We can only pick out the following
transferable passagcs:
BY crys1piiqe moiecuc is understood, the mole
| Guile in The state peculiar 10 H. when about 10 enter
into the constitution of u crystal, or when co,ist;
rnt ;,l Jp,n
| change takes place IN the nolecule nj the time Of
consolidation. The moment before, they IL
close connection, but move free y among themselves:
in the act OF crysIaization Iloy unite almost M
| Simultaneously, and are irnly Conpacied N The hard
unyielding crystal.
I'VE adopt, IN part, Wollas,on's theory of spheri-
cal and sphcro!dal molecules, and suppose the
moecue OF each primary 10 be that sphero'dal
body, cipsod, which, described within the
prism, touches the centres oil lis ioces. These mole
cncs bv their Gsgreg atiOn will build up the SGiuc
forms a. proceed from the aggregation of Ahhe
Hauys poyhcdfal molecules; for they have The
same proportional hight breadth, and thickness.
and therefore, by combination, must produce pri-
mary OF The Same dimensions.
Tie ordinary attraction OF cohesion has been con-
.dered adequate 10 produce the union OF molecules
in the construction Of rystuls. This attraction
acts, however, in every direction from the centre ut
the particle and, will cause an addition OF par
tices in no fixed direction, must invariably produce
I Il ~.
every drop of water, or g!obule OF mercury, whose
sphericily results from this kind of attraction. 10
! form solids, bounded by.a definite number OF sur
faces, there must be definite number OF directions
tor The cxerlion of the attraction If attraction Is
txcrtcd in but direction, the particles Will unite
only IN this direction, and hy their union will form
only a single line ol spheres; exerii"n in Two d.
rectOns wall, i'll II similar manner, produce hgute
| of two dimensions only, that Is, plane in three
directions, figure of htrce dimensions, or solid
! bounded by Sax faces, the cube. For the con-
siructon OF prisms, ii is therefore necessary that
the mutual attraction OF the PARTICLES be exerted III
three fixed directions in each molecule
These fixed directions may be denonnated axes,
and their extremtes poles, the one North, The other
South III each Instance Inc axes connect me CEN
tres of the faces of the prism for action in these
directions only cun produce solids similar TO the
prisms.
The attraction within molecule is not supposed
! 10 be confined TO the eXtrcmliles oil The axes. On
the contrary every portion OF the surface exers at
! traction. Bat the attraction IS strongest Ut the
| poles and weakest NJ points equidIstant between
4 comprehensive view Of the molecules aud their
axes is given i'll the following table;
Prsns. all of whose cryst. ay. axes eqqal-CaIe =.
SIs OF the eipoidai Hole the three unequal-Rt Rec.
cne tang. PRISM.
pr,s whose lat axes OBJ lat eqat COM. DAM
lquey incl; and are there RI fa0m6'c t'rtSm
oitae molccue ri. Raomjl. Prism.
1.-THE three n res, equal COIL d.
Prisuls. all of whose aNes in; .-RaOmbotedrOH
are therefore conf dam. mot aG.-O6 hhomb4e. Pr.sm
'N''' u wv ''''''' ani-Ob. R6G. Frism.
From this table ii is apparent, that all possible
positions u these diameters occur III HE iurns OIL
CRYSTALS from an equality and rectanguiarltv III The
cube through different variations III length and stu
uliun 10 II general inequality III length, and like
inequality in their mutual nclinatons, rs IN The OBJ
uie rhuinboiLu prism.
IL has been stated that the axes OF attraction have
polarity. We have not the means as Yet vi deter.
mining in every instance which ale the North, ana
when the South poles OF crystal III may low
ever be Inferred with reference 10 the rlioinboile
dron that the three poles about each vertical SOLID
angle are OF the same name those about one, NORTH
and those about the other, South In cry stalls O
tnurnalinr there is then some Correspondence be-
tween t!e cry sIaloeenic poles and those induced
by heat. Probably also i'll the ohlique prlsus, the
poles about dominant solid angle IRE nj The same
kind Ii is also probable that the poles about az
acute edge in the right prisins are OF the same knd.
Farther il!an this 1t is impossible distinguish The
poles OF the in The different primaries.
The molecules OF matter IN The act OF crysaii-
cation, are influenced by the usual principles OF aH
traction the rcDu!Sioa o like poies and tic dttr0c-
ton Of unlike tina, is two uorihs OF two souih5 re-
pei, north and II south mutual attract. here is
this peculiarly, however, that ony he nhf6e poles
Of Simti0r axes ,cW unite. An attraction exists
between tho north pole oi The vertical axis OF one
molecu!e, .nd the south pole of the vertical OF an
other but none between the north Of the vertical
axis. and the ;souh OF LATERAL when the lateral
and vertical are unlike axes. No reason can be re-
CURED Tor fact which appears 10 lie 50 natural
deduction from the general nature OF attraction.
We should rather he astuniShod II the TACT were
otherwise. |, also proceeds from the nature OF this
attractions tina, similar will by thcr union form
straight ljne; that Is, will unite.
The mos; probable hypothesis o, the process OF
crvstulization appcas to be the following at the
time OF consolidation, the molecules, leaving the
spherical form ci The fluid state, (unless thecrysal
Inc molecuie is spherei assume their ellipsoida.
forms, and cotemponDeously Their crystaiogenic
axes. These ioanls and axes depend on the nature
OF the elements N the crystalizing compound. In