108 
Origin al Commun ications. 
excess, with a few drops of muriatic and evaporated to dry- 
ness, for the purpose of destroying the organic matters. 
Third. The residuum treated with boiling water and the 
soluble portion filtered off, was clear and slightly coloured. 
Fourth. A small portion of the solution was treated with 
lime water, and gave a white precipitate. 
Fifth. To another small portion, ammoniated sulphate of 
copper was added, and gave an apple green precipitate, the 
colour was considered very characteristic of arsenite of cop- 
per. 
Sixth. The precipitate No. 5, was separated and dried, and 
with a portion of soda was exposed on charcoal to the redu* 
cing flame of the blow pipe. Copious white fumes were given 
off, having the peculiar odour of arsenic. 
Seventh. The remaining and principal portion of the liquid 
(No. 3,) was acidulated with muriatic acid and treated with 
sulphuretted hydrogen, which produced an abundant yellow 
precipitate, which was heavy and soon subsided to the bottom 
of the glass. 
Eighth. The precipitate from the last (No. 7,) was separated 
from the supernatant liquid, and a small portion reduced on 
charcoal precisely as No. 6 ; at first the fumes of arsenic came 
off mixed with the sulphur volatilized along with it. But to- 
wards the close of this operation the well known fumes of 
arsenic came off apparently pure. 
Ninth, The remaining portion of the precipitate from No. 7> 
was submitted to the reducing experiment in glass tubes, 
When the heat was applied there arose, first yellow sulphuret 
of arsenic, which attached itself to the upper parts of the tubes; 
next the red coloured sulphuret, which attached itself a little 
below, and lastly the metallic arsenic, which attached itself in 
small scaly crystals just at the lower surface of the red sul- 
phuret. 
Several of the experiments here mentioned are alone suf- 
ficiently conclusive to satisfy the chemist of the presence of 
arsenic, but taken altogether, they form a mass of testimony 
derived from different processes which clearly places the fact 
beyond the possibility of a mistake. The precipitate No. 7, 
