78 Intelligence and Miscellaneous Articles. 



these two substances leave no doubt in their mind as to their pro- 

 duction during the spontaneous decomposition of cyanogen when 

 dissolved in water. If M. Vauquelin had pursued the examination 

 which he had commenced in the products of this reaction, he would 

 perhaps have first made the admirable discovery, which was effected 

 fifteen years afterw^ard by M. Woehler, of the artificial production of 

 animal matter. 



It is extremely curious to observe a substance of comparatively 

 simple composition, such as cyanogen, give rise to so many diflferent 

 products by its reaction on water. 



Admitting Az^ C^ H« O^ [O* ?], as its composition the decompo- 

 sition of cyanogen in water may be explained by the following equa- 

 tion: 



1 atom of Urea Az* C'^ H^ O^. 



3 do. Hydrocyanic Acid .... Az'^ C H'^. 



4 do. Carbonic Acid C* 0«, 



1 do. Ammonia Az^ H^. 



1 do. Oxalate of Ammonia . . Az^ C'^ H** O*. 

 1 do. Black Substance Az* C^ H^ O*. 



Az22 C22 H36 0»8. 



L'Institut, March 1838. 



BICHROMATE OF PERCHLORIDE OF CHROMIUM.* 



This remarkable compound was discovered by Berzelius ; it was 

 at first called perchloride of chromium, because when put into contact 

 with water it was changed into chromic and hydrochloric acids. Its 

 true composition was ascertained by M, Heinrich Rose. 



M. P. Walter gives the following process for preparing this com- 

 pound : put into a tubulated glass retort an intimate and finely 

 powdered mixture of 100 parts of fused common salt, and 168 parts 

 of neutral chromate of potash ; an S tube is to be put into the tubulure 

 of the retort, through which there are gradually poured 300 parts 

 of concentrated sulphuric acid. The action is rapid from the com- 

 mencement ; intense red vapours, accompanied by much chlorine, are 

 disengaged. ITie receiver is to be kept cold to condense the vapour. 

 The acid must be gradually added, or otherwise a loss of the red 

 vapours will take place, and besides this the contents of the retort 

 rise and pass into the receiver. As soon as the acid is added, the 

 retort is to be gently heated, and the heat is to be increased until 

 yellow vapours begin to arise ; the operation is then finished. In 

 the receiver there is found a liquid of an intense red colour, and a 

 solid substance, which, according to M. Dumas, is a compound of 

 this substance with chlorine. By decantation they may be sepa- 

 rated, and the liquor when rectified, so as not to obtain the whole of 

 it, yields a compound, the boiling point of which is constant. 



The liquid thus obtained is of a magnificent blood-red colour ; it is 

 volatile, and yields fumes abundantly ; when put into a quantity of 



* See Lond. and Edinb. Phil. Mag., vol. xii. p. 83. 



