540 Products of the Decomposition of Cyanogen in Water. 



prussic acid, and a new acid which he considered as com- 

 posed of cyanogen and oxygen. 



The opinion of M. Vauquelin upon the nature of this latter 

 substance was solely founded upon theoretical views, for he 

 had neither isolated his new acid, nor studied any of its com- 

 binations. 



The experiments which we proceed to detail, authorise 

 us to say, that M. Vauquelin had deceived himself in an- 

 nouncing the formation of cyanic acid by the decomposition 

 of cyanogen in water, and that the matter which he had con- 

 sidered as cyanate of ammonia was a mixture of urea and ox- 

 alate of ammonia. 



A solution of cyanogen in water, prepared in the ordinary 

 manner, was exposed to the action of light, till all odour of 

 cyanogen had disappeared. The new liquid had a strong smell 

 of prussic acid; its colour was slightly yellow, and its reaction 

 ijeutral. A black, flocky, light substance had fallen to the 

 inferior part of the solution. It was collected upon a filter, 

 and freed from all foreign soluble matters by washing with 

 distilled water. After this purification it was slightly soluble 

 in water and alcohol, insoluble in aether; soluble, on the con- 

 trary, in acetic acid and the caustic alkalies, and possessed the 

 property of forming true salts with the various bases. 



The small quantity at our disposal did not permit us to 

 submit it to an examination as rigorous and extended as we 

 could have desired. However, from the analysis of its com- 

 bination with the oxide of silver we have reason to believe 

 that its true composition may be expressed by the following 

 formula : 



Ns C, He O4. 

 A part of the liquid was boiled, and the vapour disengaged 

 was conducted through lime-water. An abundant precipitate 

 of carbonate of lime was formed, leaving no doubt that car- 

 honic acid was formed during the decomposition of the cyano- 

 gen in water. The remainder of the liquid disengaged during 

 its concentration a quantity of ammonia and prussic acid. 



The dry residue had a slight yellow colour, and a saline, 

 sharp taste. Treated with alcohol, it was divided into two 

 nearly equal parts. The portion soluble in the alcohol pos- 

 sessed all the characters oiurea. 



The residue, insoluble in alcohol, was oxalate of ammonia. 

 From the analysis of these two substances and the minute 

 examination of their properties, there can be no doubt re- 

 specting their production in the spontaneous decompositicm 

 of cyanogen dissolved in water. If M. Vauquelin had pur- 

 sued the examination which he had commenced of the pro- 



