C. L. Jackson— Methyl and Benzyl Compounds. 139 
predominating in the small existing glaciers of temperate 
climates, but the rounded or nether-formed greatly predominat- 
ing in the grand old glaciers of which we have been speaking. 
In the terminal deposits of these, especially in the materials 
pushed into the lake, it is somewhat difficult to find a boulder 
which has not been subjected to severe attrition. 
Art. XX.— Cer xa Methyl and Benzyl Compounds containing 
Selenium; by C. LORING JACKSON. 
Merayt Compounpns. 
Methyl Monoselenide (CH ,),Se.—The only previous research 
on this compound is one by Wohler and Dean,* but it is evi- 
dent from the properties and oxidation product described by 
them, that they obtained the ay d:selenide (CH,),Se,, ae 
not the methyl monoselenide (CH,,),Se. In fact Rathke, so 
years later,t showed that in the cae series their process yielded 
principally ©: H,),Se,,and but a comparatively small quantity 
of (C,H,),Se. Under the direction of Professor Hofmann, in 
the Berlin Laboratory, I have prepared the methyl mono- 
selenide according to the process by which Rathke succeeded 
in obtaining aaye monoselenide, and find that it differs entirely 
from the substance described under that name by WoOhler an 
Dean, but is analogous to (C,H,),Se prepared “by Joyt and 
Rathke. Further, I find that in the benzyl series this process 
yields (C,H.,),Se, Mee that adopted by Wohler and Dean 
yields principall y (Cc, Hi} Se.. 
Methyl Monoselewide (C, H,).Se was prepared by distilling a 
mixture of strong _solutions of NaOH and CH,KSO, with 
‘ The freed from water was purified by frac- 
tional distillation. 
Caleulated for eee § Observed. 
CONVO as 5 SS 22°07 
Hydrogen... _- as 5°51 
It is a colorless liquid with a sa po luster and most offen- 
sive odor. Boiling point 582° (uncorr.). It burns with a 
blue selenium ame, is heavier pe psi na does 1 not mix 
ree. : 
5 
affected by hydrochloric acid or sodic hydrate solution, but dis- 
solves in strong nitric acid, forming 
* Ann. Chem. Pharm., xevii, p. 1. + Ibid, clii, p. 208. Hi boreee feo p. 36. 
atomic weight used for Se was 78, that giv y Lothar Meyer in 
his Moderne Theorien der Chemie. 
