M. C. Lea— Detection of Hydrocyanie Acid. 121 
easily, and the solution conducts itself in the same manner as 
that above mentioned. e action of the amalgam is then due 
alone to the formation of caustic soda, and not to the action of 
nascent hydrogen. 
In order to obtain the red substance above referred to, the 
original body was dissolved in warm alcohol, and to this solu- 
tion an alcoholic solution of caustic soda was added. In this 
are boiled. Very concentrated aqueous ammonia does not act 
oa the substance C*H*O%, even when the two are boiled to- 
gether. 
I intend to study the action of phosphoric chloride and acetyl 
chloride, and, further, of nascent hydrogen in acid solution, 
produced by tin and alcoholic chlorhydric acid, upon the body 
under investigation, and expect in this manner to reach definite 
results which will lead to a knowledge of its constitution. 
October, 1874, 
—_—. 
Arr. XV.—On the Detection of Hydrocyanic Acid; by M. 
Carey Lea, Philadelphia. 
1. New Test. 
Tf a little pure protosalt of iron (I have used ferrous ammo- 
nia sulphate) be dissolved together with a little uranic nitrate, 
ave a solution which, with a soluble cyanide, gives a pur- 
Ple precipitate, or in very dilute solutions of the cyanide, a 
greyish purple. 
