—_ — 0 tae 
Analysis of Argentine and Steatite. 333 
E. The liquor (D), when treated with an excess of caus- 
tic potash, afforded 0.72 grammes of magnesia on 3 grs. or 
24.0 per 100. 5S a 
The constituents of this mineral are, therefore, _ 
Per 100 parts. 
1 
A. Water — - -033 Containing oxygen, -- 
B. Silica §6.333...- - - = 2 028633 
C. Protoxide ofiron 4.300 - - ~ - 00.97 
C. Alumina - 1.666 é 
D. Lime - 10.666 ie je - ot QRS4 
E. Magnesi - 4.000 - - - mites REQ 29 
C. Protoxide of chrome a trace. ———— 
igo J) 92.998 
100.000 
2.002 Loss. 
i enieeemeemmeenmmmmmmndll 
y 
Ant. XVII.—Analysis of Argentine and Crystallized Sleatite. 
by Professor Dewey. 
Argentine. 
At the lead-mine in Southampton, Mass. a mineral is 
found in considerable quantity, which is a nearly pure car- 
bonate of lime, and has the following characters. It gen- 
erally consists of undulated, not parallel, laminz, of a pear- 
ly shining lustre, often of a beautiful silvery white. _Some- 
times it is in thin plates, which intersect and form small 
cells, containing crystals of calcareous spar. The thin la- 
ming are translucent. Sometimes it is less laminated and 
more compact, with less lustre, and the cross fracture is 
slightly granular. It was supposed to contain magnesia, 
and three years since |] examined it without detecting any 
of this earth. It was then laid by as a beautiful carbonate 
of lime, without a suspicion of its being one of the sub-spe- 
cies of this mineral. The characters prove it to be 4rgen- 
fine. : 
It occurs on very compact granite, and is also associated 
with fetid quartz, which is found in small masses in it and 
upon it. When it joins the quartz it is more compact and 
