1076 The American Naturalıst. [November, 
in pegmatite or in quartz veins, in quartz lenses in schists, or imbedded 
in granite, mica-schist, hornblende rocks, crystallized limestones, or 
garnetiferous beds. Oebbecke * describes briefly a small crystal of 
arsenopyrite from the granular limestone of Wunsiedel, in the Fichtel- 
gebirge. Its composition is: As— 46.91; S.— 18.64; Fe — 34.31. 
Mr. Diller?* announces the discovery of native go/d in calcite 
from near Minersville, Trinity Co., Cal., and Mr. Hersey 2% mentions 
the discovery of arsenic in nodular masses in a silver and gold mine a 
few miles west of Leadville, Colorado. Magnetite crystals from 
serpentine in New Zealand are reported by Prof. Chester ? to have the 
composition following : 
Fe,O, FeO Mn,O, MgO CaO SiO, 
66.71 19.62 4.63 7.15 tr. 2.38 
The silica is supposed to come from particles of silica adhering to the 
crystals. ——Lacroix ? believes that carphosiderite is a much more 
common mineral than is generally supposed. 
Mineral Syntheses.—By an interesting series of experiments, 
that are in the main but modifications of well-known processes, Wein- 
schenck ? has prepared metallic sulphides with many of the properties 
of the natural compounds. By distillation of the oxides with sal- 
ammoniac and sulphur he obtained crystals of pyrite and of a regular 
copper sulphide with the composition of chalcocite. By the action of 
sulphuretted hydrogen under pressure upon the proper salts, galena, 
argentite, covellite, cinnabar, orpiment, troilite, millerite, and alaban- 
dite were produced. Corundum, diaspore, and rhodochrosite were 
obtained by the action of urea upon suitable compounds in solution. 
Other experiments afford an insight into the method of formation of 
the minerals of the apatite group. The paper is a valuable contribu- 
tion to the study of the genesis of some of the most important of the 
common minerals. Messrs. Hautefeuille and Perry ® have dissolved 
alumina in nepheline, and have gotten a vitreous paste in which are 
many hexagonal plates of corundum, Michel 3! has produced 
M Zeits. f. Kryst., etc., XVII., 1890, p. 384. h 
% Am. Jour. Sci., Feb., 1890, p. 160. 
2 Ib., p. 16r. 
21 Min. Mag., 1889, VIIL., p. t25. 
% Bull. Soc. Franc. d. Min., Jan., 1890, p. 8. 
29 Zeits. f. Kryst., XVII., 1890, p. 486. 
3 Bull. Soc. Franc. d. Min., 1890, XIIL., p. 147. e 
VW Ib, p. 139. 
