50 F. W. Clark on separating Tin from Arsenic. 
It is best to have present in the solution, while boiling, a little — 
dilute chlorhydrie acid. 
f antimony also is contained in the mixture, it is necessary, 
just before ceasing to boil, to add to the solution an equal vol- 
ume of strong sulphydric acid water, to reprecipitate any of 
that metal which may have gone into solution. Upon filtering 
nary tests, and the molybdic sulphid is absolutely free from tin. 
al i 
these cases it is assumed that the tin is in the form of 4 
a stannic compound. o 
the tin. The precipitate which at first varies from white to 
pale yellow, rapidly darkens in color, and seemi ist 
i d t 
rse mony, 
separation, respectivel 
the second case was 
phur solution of the two metals as ammonia-magnesian arsen- 
rthless, 
rtions of tin and antimony a 
xydized a weighed quantity of — 
, Tegarding the 
aceole of years ago I made a few experiments upon i 
