Chemistry and Physics. 123 
of suboxyd. For a second operation we may take 1 part of nitre, 1 of 
this oxyd, and 1 of metallic copper. After complete washing, the oxyd 
Density of Selentum.—Scuarreortcu has determined the density of 
Selenium, and deduces from a great number of experiments the follow- 
ing conclusions : 
.) Selenium has two different specific gravities, (at 16° R.) namely, 
4.282, and 4:801. The smaller number belongs to an amorphous and 
glassy condition; the higher one to a granular crystalline state; the 
two states may be converted into each other at pleasu 
With iodid of methyl a similar base was produced, the iodid of which 
has the formula CsaHis (C2Hs) NOc+HI; the author terms it me- 
