SULPHIDE OF ARSENIC IN SULPHIDE OF ANTIMONY. 595 
if sulphide of arsenic was present, the process of Wackenroder 
was adopted (Fresenius). Twenty grammes are deflagrated 
with forty grammes of nitrate of potash and twenty grammes 
of carbonate of soda, by projecting the mixture gradually 
into a red-hot Hessian crucible. The resulting mass is 
lixiviated with water, filtered, the filtrate acidulated by hy¬ 
drochloric acid and sulphurous acid added, after which sul¬ 
phuretted hydrogen is passed through it. The moist preci¬ 
pitate is digested with carbonate of ammonia, filtered, acidu¬ 
lated, and precipitated as tersulphide of arsenic. This 
method is not rigidly accurate, as traces of either sulphide 
of antimony or of free sulphur may contribute to give too 
high results. 
I give below the results obtained with four distinct speci¬ 
mens of sulphide of antimony : 
No. 1 contained sulphide of arsenic T33 per cent. 
2 „ „ *27 
3 
yy 
4 
>> 
1-16 
•25 
yy 
yy 
Thus it appears that No. 1 (that given to the calves) con¬ 
tained far more arsenic than did some other specimens, 
amounting to 5*84 grains of tersulphide in an avoirdupois 
ounce, being the dose which proved fatal. 
The dose of black antimony may be considered unrea¬ 
sonably large, but I know of no grounds for supposing that 
the antimony produced the mischief. Large doses of this 
substance are constantly given to animals. Pereira speaks 
of doses of two to four ounces being given to horses, and of 
half an ounce taken by a man for several days without bad 
effect. 
It appears, then, that the arsenic present was the cause of 
mischief. The dose of pure sulphide of arsenic has not 
been determined, and it has often been regarded as compa¬ 
ratively inert. This is doubtless correct, as long as it retains 
its insoluble condition. Meclicina non aguntnisi soluta. But, 
singularly enough, in selecting urine as a vehicle for dosing 
the calves, their owner was providing for the solution and 
prompt absorption of the sulphide of arsenic. When it was 
dissolved by the ammoniacal urine, its poisonous properties 
would probably be just as great as those of a similar quantity 
of arsenious acid in solution. 
Gmelin gives a process for purifying commercial black 
antimony from arsenic, by digesting the powder with twice 
its weight of aqueous ammonia for forty-eight hours with 
stirring, then filtering, and washing the product, which is 
