186 
PHARMACEUTICAL NOTICES. 
Cyanuret of Silver. 
This article, which is used for the extemporaneous produc- 
tion of hydrocyanic acid, is officinal in the New London 
Pharmacopoeia, and is likely to be included among 'the num- 
ber of new preparations proposed to be introduced into the 
forthcoming edition of the U. S. Pharmacopoeia. There are 
three methods of obtaining this substance. The first is that 
of the London, which is to decompose nitrate of silver in solu- 
tion by dilute hydrocyanic acid. The second is the most 
eligible method for manufacturers, and consists in directing, 
through a solution of nitrate of silver, a current of hydrocyanic 
acid gas, until it ceases to throw down a precipitate. The 
gas is obtained by treating prussiate of potash with sulphuric 
acid in a glass retort ; which should be connected by a glass 
tube with the vessel containing the solution of silver. The 
third method, which I am about to detail, offers a ready means 
of obtaining this substance, wherever perfectly dry, undecom- 
posed cyanuret of potassium can be procured. 
It is as follows: 
Take of Cyanuret of Potassium, 5 drachms or 15 parts f 
Crystallized Nitrate of Silver 11 drachms, one scruple, 34 
parts ; distilled water 16 ounces or 384 parts, — by measure. 
Dissolve the two salts separately, in the distilled water; 
mix the solutions together, stir with a glass rod, then throw 
upon a filter, and wash the precipitate with distilled water ; 
lastly dry the cyanuret in the dark, by the gentle heat of a 
stove. 
Composition. 
1 eq. Cyanogen 26.436 or 19.4. 
1 " Silver 10S.305 " 80.6. 
134.000 100.0. 
Iodide of Jirsenic. 
This combination is prepared according to Plisson, by di- 
gesting three parts of arsenic in fine powder, with ten parts 
