Geology and Natural History. 485 
Analyses of a similar mica from other localities afforded results 
agreeing more or less closely with the above. Its claim for recog- 
nition as a species distinct from biotite and lepidomelane rests 
chiefly upon the relative proportion of the two oxides of iron. 
4. Ueber den Boracit von H. BaumHavER.—Through an investi- 
explains the occurrin y 2 somewhat different and more 
simple method of twinning. he method of investigation 
empl is one which he has done much to develop, and which 
he has successfully applied to the solution of other similar prob- 
lems.—(Zeitsch. Kryst., iii, 337. 
5. Genaue Messungen der a apa att aus der Knappen- 
2 A 
ni 
n into account, the indefati- 
gable editor will —— need, and ought freel 
si aids which can be a beg 
chat indispensable auxiliaries which he j 
been withdniwe from the Government Botanist’s department. 
