* 
Mineralogy and Geology. ie 
Il. MINERALOGY AND GEOLOGY. 
1, Pollux, a silicate containing a large amount of Cesium.—Pisant 
has made an ana ysis of this rare mineral species, and finds it to contain 
34°07 per cent of cesia, with but traces of potash. The specimens ex- 
r L, Seemann, of Paris. One crystal of 20 grams weight had distinct 
cubic faces, with trapezohedral planes like analcime, thus confirming Des 
o 
gum-like on the natural surfaces of the crystals. Colorless, H.=6 5, 
G.= 2-901. In the closed tube, becomes opaque, and gives off water. 
In the forceps, whitens and fuses with difficulty, coloring the flame yellow. 
Small particles of the mineral heated with fluorid of ammonium on a 
Si Al Fe * H 
44°03 15:97 068 0°68 34:07 3°88 2°40=101-°71 
Oxygen, 2348 743 020 O19 197 100 213 
* With a little lithia. 
The platin-chlorid of caesium obtained in the analysis showed traces of 
potash when submitted to spectroscopic examination. It was reduced by 
hydrogen, and subsequently the quantities of chlorine, platinum and 
Cesium were determined, aud found to accord with theory, thus showing 
it to be a pure cesium sa!t.— Comptes Rendus, \viii. 
sae mineral species was previously analyzed by Plattner, who ob- 
hed; 
Si Al Fe koe H 
46-20 1639 086 1651 1047 282=-92-75" 
* With a little lithia. 
oe 26°13 KCl; and converting the 10-47 soda into chlorid, we obtain 
NaC 
KCl into platin-chlorid of potassium, it amounts to 85°65 KCI+-PtCl,, 
and considering this to be a cesium salt, instead of a potassium salt, 
* Would be equal to 42-65 CsCl. As the soda in the analysis was prob- 
ably calculated by ascertaining the difference between the sup 
“Morid of potassium, and the total weight of alkali-chlorids, this amount 
is materially lessened when the chlorid of cesium found (42°65) is sub- 
tracted from the total amount of chlorids (45°87), giving but 3°22 NaCl, 
* Pogg. Ann., Ixix, 443. 
