T. S. Hunt on the Compound Ammonias. 209 
Let arsenic replace nitrogen in Wurtz’s ethammine Me: os 
NC:Hs, HH, and we have AsC2Hz, from which if Ha: be ab- 
stracted, there remains AsC:Hs=AsC:Hs, HH, a new base 
corresponding to stibethine ; such a base is contained in the chlo- 
rid of cacodyl, and has been recognized by M. Gerhardt under 
the name of arsine,* of which the hydrochlorate and hydrobro- 
mate, are Bunsen’s chlorid and bromid of cacodyl. The com- 
‘ tively indifferent to chemical agents, and but difficultly oxydized : 
mercury and nitrate of silver with alcarsine, are probably com- 
pounds of arsine, analogous to the ammoniacal combinations of 
these salts. It is to be remarked that while the salts of stibethine 
are; from the very mode of their formation, acid, those of arsine, 
if we except perhaps the sulphate, are neutral. 
Cacodyl is formed by the reduction of the hydrochlorate of 
arsine, chlorid of arsenium, by zinc; precisely as 2Zn Cl+Ka 
ive 2K Cl+-Znz2, we obtain chlorid of zinc with the elimination 
of arsenium, that is, of As C:H6+AsC2Hs=C1H12Asz, : 
dyl is thus precisely analogous to a metal, and with chlorine or 
breaks up to form two equ 
onthe tha, 
