covery of the new forms + £ goth: og RSL z 
r 
3 
=. eoin si 1 SRS + fa EES + l æ RS As indicated 
r 2 Io g t o 
by these formulas, Becke finds dolomite to be rhombohedrally tetra- 
hedral. In addition to the full lists of forms occurring on the 
mineral, there is in the paper a full discussion of its vicinal planes, 
—Pyrite crystals from the clay slates near Trofajach in Steiermark, 
contain the new plane ea Michel? claims that crystals of the 
selenates of barium, strontium, calcium and lead are isomorphous 
with the natural sulphates of the corresponding metals. 
quartz consisted in a change in the nature of the circular polariza- 
tion of the alternate lamelle, and not in such a change as 
chemistry for the purpose of determining the nature of the inner 
structure of carbonaceous substances.—Becke® proposes a method 
' Hoefer: Ib., x., p. 157. 
? Bull. d. 1. Soc. Franc. d. Min., xi., p. 182. 
1 
Miner. Magazine, 1888, p. 1. 
; Technology Quarterly, May, 1888, p. 397. 
x Amer. Chem. Jour., x., p. 405. 
Min. u. Petrog. Mitth., x., p. 89. 
