+<.. 
Antimony in the organs and tissues. 277 
either the platinum alloyed with the zinc is sufficient to retain fully 
50 per cent. of the metal, or as is very probable, the zinc itself causes 
a precipitation of a portion of the antimony. That this is a point 
overlooked by most writers on chemical toxicology, is evident from 
a perusal of the literature on the subject. 
Whether it would be possible to obtain all of the antimony as anti- 
moniuretted hydrogen, in the absence of any metal other than per- 
fectly pure zinc, we cannot say. Certainly as a method for quantita- 
tive purposes, it would be too tedious a process to admit of general 
use, especially where such small amounts of antimony, as in our own 
experiments, would limit galvanic action to a minimum. That the 
method is capable of showing the presence of very small amounts of 
antimony, is unquestionable. Wormley’s experiments* are very de- 
cided on this point, but evidently only a portion of the antimony will 
be recovered. 
Precipitation of the antimony by hydrogen sulphide and final oxi- 
dation by fuming nitric acid and weighing as Sb,O,, gave fairly satis- 
factory results, when the weight of antimony was not less than 10 
milligrams of Sb,O,.. With smaller amounts, the results were far too 
high, owing probably to the far greater proportional increase of sul- 
phur. Attempts to weigh as sulphide, after fusion of the first hydro- 
gen sulphide precipitate with potassium nitrate and carbonate, like- 
wise gave too high results when the amount of antimony was small. 
Further, the two latter methods are somewhat unsatisfactory, in that 
when the amount of antimony is very small, the nature of the final 
products is such, it is difficult to be certain of the purity of the mat- 
ter weighed. 
Owing to this reason partly, we next turned our attention to the 
electrolytic method for the separation and determination of antimony, 
as in this case the appearance of the metallic mirror is in itself a fair 
guarantee of the nature of the deposit, and its purity is easily proved: 
Alex. Classent has shown the accuracy of the method in general 
quantitative work, where moderate amounts of antimony are present 
(0°15—0'2 grams Sb). In his experiments, the antimony, in the form 
of sulphide, was dissolved in ammonium sulphide and the solution 
then exposed to electrolytic action. The ammonium sulphide solu- 
tion must be free both from polysulphides and from free ammonia. 
* Micro-Chemistry of Poisons, p. 229. 
+ Quantitative Analyse durch Elektrolyse. Berichte d. deutsch. chem. Gesell., xvii, 
p. 2474. See also Alex. Classen and Rob, Ludwig, ibid., xviii, p. 1104. 
