1890.] Mineralogy and Petrography. 1193 
Va., comports itself more like a meta-silicate than like a basic pyro- 
silicate. They therefore decide against Groth’s formula for this min- 
eral, and propose instead the formula H,Mg,(SiO,),. Crystals of 
sulphur containing twenty-one forms line clefts in galena at Bassick. 
Their axial ratio is a: 4: c——.8151: 1: 1.9066. —Busz," who de- 
scribes these sulphur crystals, describes also in the same article a deryl 
crystal from St. Piero, Elba, AZuorspar and géthite from Cornwall, 
hypersthene from Monte Doré, and corundum from Lake Laach. 
Bucklandite from the Pfitschthal, Tyrol, and epidote crystals from 
Oberhollersbachthal in Pinzgau, and from Floss in Bavaria, have been 
examined crystallographically by Brugnatelli.7 Pyrophysalite oc- 
curring in a granite dyke at Finibo in Sweden, augite from Risoe in 
Sweden, and martite from an iron mine in Ypanema, Sad Paulo 
Province in Brazil, have been briefly described by Kenngott.—— 
The composition of arsenopyrite,” from Goldkronach and from Neu- 
sorg in the Fechtelgebirge is : 
S As Sb Fe Bi Co- Ag Sp. Gr. 
Goldk. 20.84 41.36 3.73 3497 : .002 6.09 
Neusorg. 17.27 42.89 34.64 4.38 tr. 5.96 
Chalcocite® from the Kathrina mine near Innsbach, in the Bava- 
rian Pfalz, contains: 
Cu Fe As S Coand Ag Sp. Gr. 
48.44 — 93 Les 40.13 tr. 5.68 
Minium from Leadville, thought by Mr. Hawkins? to be a 
pseudomorph after galena, has been examined with the following 
result : 
Pb,O, FeO, "V,O, Insol. Sp.Gr. Hardness. 
91.39 ‚so "94 7-51 4-57 2.5 
Mr. Seamon 3 thinks that the ca/amine of Missouri was produced 
by segregation from zinciferous clays formed by the reaction between 
zinc sulphide and hot silicious waters. Baumhaur’s # recent investi- 
gations on apatite crystals from various localities affirm the statement 
that the density and axial ratio of this mineral increase with the de- 
crease of chlorine in its composition. In a short communication 
26 Zeits. f. Kryst., XVIL., p. 549. 
27 Ib., XVIL, p. 529. 
28 Neues Jahrb. f. Min., etc., 1890, L., p. 87. 
29 Sandberger. Ib., 1890, p. 99. 
30 Amer. Jour. Sci., Jan., 1890, p 42. 
31 Ib., 1890, p. 39. 
32. Zeits, f. Kryst., XVIII., 1890, p 31. 
