mineral species independent of Phenomena of Isomorphism. 201 
ance. Similar changes in the appearance of many minerals are 
familiar to the eg They are seen in calcite, heavy 
spar, Anglesite, and s nee and may serve as guides in tracing 
variations of compos 
Aguin, the euibe. ponent of the crystals, both of Sb Zn? and 
Sb Zn*, was taken with great care through the whole series, and 
the results are tabulated below. The union of the two elements 
is attended with an increase of volume, and this increase is at a 
maximum at the points corresponding to the theoretical compo- 
sition. These points would therefore be marked in a set of erys- 
tals by being points of minimum specific gravity; and they 
d be determined with great accuracy by means of this prop- 
erty, even in a series of alloys of the two metals which had not 
been crystallized. This fact is illustrated by the following Table, 
repriated from the original memoir. 
Specific Gravities of Crystals formed in the Alloys of Zinc and Antimony. 
‘Sy grachae of the nie gies of the | Spec. grav. | Mean spec.) pe nansion 
alloy 4 crystals. of oeyetals grav. me iis cpa 
Percent , P by fa tn zinc an link 
of in | of Sh. | ora | eee antimony. : 
a ee ee! Soe Wee | se eee 
ded ee waar 7-069 | 7138 | 0-064 
*86 20 15°80 san bers 6898 7-082 0184 
*76°30 3°70 6769 7-032 0 263 
4480 | 5520 | 44-26 574 | 6841 | 687 
{4280 20 | 4309 | 56-91 6874 
*40°:00 | 60-00 any 6386 | 6860 
600.16500. 1 ..:. | pc dee eee bees 
8300 | 6700 | 3637 | 6463 | 6401 | 6838 Dons 
$2950 | 70:50 2 | 638 | 63st | 6830 | 0 
HY50 | 72:50 | 33:35 | 66-1 383 ak eee 
2650 | 7350 | soos | -6792 | 6400 | 6892 | ove 
2600 | 7400 | 31-07 | 6893 | S418 818 von 
25°50 44:50 80°43 69°57 6 428 6816 oo 
2450 | 7550 | 2876 | 7124 | 6449 80 neve 
22 50 50 26°62 43:38 6" 6798 os88 
21-50 4850 94:83 4617 6467 6°790 : 
*1500 | 8500 | 6664 | 6744 
"1600 | -go00!:| o> ed ew OTA os 
. 4 95 00 bien ere 6655 par dan 
pe iodoe. | ic emma oe 
eee 
P Alloys hot crystallized, +! Point of typical composition of Sb Zn’, 
ii ae of typical composition of Sb Zn? 
OUR. SCL—SECOND SERIES, Vot. XXX, No. 89.—SEPT., 1860. 
26 
