Mineralogy and Geology. 267 
white heat. Ata full white heat the subphosphate of lime was decom- 
posed, with slow evolution of its phosphoric acid. Lime, magnesia, 
and particularly alumina, were found to aid materially by their pres- 
ence, in the decomposition of the sulphates and chlorids of potash and 
soda, which alone suffer only an imperfect decomposition by the agency 
of hot watery vapor, because of the volatility of the hydrates of these 
alkalies at a high heat. 
As potash alum is completely decomposed by steam at a high tem- 
confirmed the conjecture: Partial fusion of the fragments of feldspar 
w 
strongly alkaline, and proved to contain aluminate of potash. Dilute 
sulphuric acid also produced a small portion of alum from the powder 
which had been exhausted with water. 
: port 
for 1846, 24 part, p. 125, an abstract of which will be found in this 
Journal, i ser., xlviil, 397.—B. 8., Jr.] 
Il. MineraLocy AND GEOLOGY. 
1. Brandisite, a New Mineral; by M. Harprcer, (Neues Jahr- 
buch, fur Min. Geog., &c., 1847, p. 349.)—Brandisite occurs at Mon- 
zoni in the Fassa-thal. Its crystals are six-sided prisms, secondary to 
a rhombohedron, with a transverse cleavage. Lustre, pearly and vit- 
Feous. Color, leek green to reddish gray, or leek green in the direc- 
tion of the axes, and brown transversely. H.=45. G.= 3015 — 
3-06 Thin folia not elastic. Affords the reaction of silica, alumina 
and iron before the blowpipe. 
* See this Journal, i ser., xlv, 104; xlvili, 82. 
Stconn Surizs, Vol. VY, No. 14.—March, 1848. 35 
