84 Dr. Genth’s Contributions to Mineralogy. 
with sulphid of ammonium. The remaining sulphid of copper 
was dissolved in nitric acid and the oxyd of copper precipitated 
from the boiling solution by caustic potash. It gave 00512 grs, 
The filtrate from the sulphid of copper was saturated with hy- 
drochloric acid and the precipitated sulphids of arsenic and anti- 
mony oxydized by chlorate of potash; chlorid of ammonium, 
tartaric acid and ammonia were added, and the arsenic precipl- 
tated by sulphate of magnesia as arseniate of magnesia and am- 
monia. This precipitate contained 0-008 grs. of magnesia. 
The filtrate from the precipitate by hydrosulphuric acid gave, 
after having been oxydized by nitric acid, 0-0027 grs. sesquioxyd 
of iron, precipitated by ammonia; the filtrate from it gave with 
sulphid of ammonia a precipitate which yielded 0-0042 grs. of 
oxyd of zine. 
Sulphur and antimony were determined from the loss and by 
calculation. The analysis gave: 
Ag 1053 p.c. which require 157 sulphur for AgS 
Cu 3073 « * 780 “ Cug 8 11-43 
Zn 2-53 “ “ 1:25 “ Tn a 
Fe 43. * 403 O81 FeS 
As 1145 © * 4-42 # As S3 14:05 
Sb 171g 3 6°63 « SbSs3 
Ss 25:48 “ —— 
100-00 25°48 
The ratio of sulphur of the sulphobasis and sulphoacids is: 
11-43 : 14-05 or L: 1-23, corresponding with the formula, 
5(Ag, Cus, Zn, Fe)S+2(As, Sb)Ss 
It will be seen that this composition differs from that of gray 
copper, which is 4(Ag, Cus, Zn, Fe)S+(As, Sb)Ss. As I had 
Apophyllite—T he analyses of apophyllite from different 
localities show such a difference in the quantity of fluorine pres- 
ent (varying from 0-34 to 1-54 p. c.), that Rammelsberg suggested 
it might be a silicate in which a part of the oxygen is replaced 
by fluorine. 
vitreous and unchanged. Bergen Hill, N. J., afforded many spe- 
cimens of this kind. I am not aware that investigations have 
ever been made in order to determine, whether the opaque and 
