192 R. Napoli on Arseniuretied and Antimoniuretted Hydrogen. 
he two gases are also decomposed by aqua-regia, with the 
formation of chlorid of arsenic, and perchlorid of antimony. B 
a careful distillation of the mixture, the arsenical chlorid passes 
over first, while the chlorid of antimony remains in the retort, as 
has been shown by Malaguti and Sarzan. An analogous reaction 
is produced with strong hydrochloric acid, but with this differ- 
ence that the arseniuretted hydrogen is almost entirely decom- 
osed, while the antimonial gas undergoes a less complete decom- 
position. 
The applicability of these reactions to the concentration and 
separation of the arsenic and antimony, in the gas obtained by 
Marsh’s apparatus, will now be apparent. Instead of burning oF 
then pass the gas into the hot nitric acid, which completely de- 
composes in the manner just described, any compounds of arsenic 
or antimony which may be evolved. If the nitric acid remains 
ne 
ferred to a small flask, the apparatus washed out with a little 
nitric acid, and the whole carefully evaporated to one-half. If 
there is no precipitate, the absence of antimony is certain; W® 
then evaporate still further to remove the excess of acid, dilute the 
residue with water and examine it like a pure solution of arsel¢ 
acid. Should the nitric acid appear turbid either before oF after 
evaporation, antimony is present, and perhaps arsenic ; in this 
case, after evaporating as before to a small bulk, we add water 
and filter, the antimony remains behind in an insoluble conditio?; 
while the arsenic, if any were present, is held in solution, 
In the case of a mixture of arsenic and antimony we may a 
a small tubulated retort, to which can be adapted a small re- 
ceiver, we introduce through the tubulure, a tube reaching any 
to the bottom of the retort, in which is placed a small quantity 
