of Chlorine and Cyanogen. 31 



continued to be sent through the liquid till the crystals of sal- 

 ammoniac begin to form, which is accompanied by the violent 

 effervescence I have before mentioned, owing to the escape of 

 carbonic acid gas. 



The cause of these phaenomena is owing to the decomposi- 

 tion of chloride of cyanogen, by its constituents uniting with 

 the elements of four equivalents of water, and giving I'ise to 

 sal-ammoniac and carbonic acid, as will be readily seen from 

 the following symbols. 



or C2 No Q\ + Hg O4 = C, O, + Na Hg Cl^. 



Properties of the Compound. 

 The compound crystallizes in long, soft, perfectly white 

 needles, of a silvery lustre ; they very much resemble sul- 

 phate of quinine : it is neutral to test paper; it is tasteless 

 and inodorous; it melts at 140° C, by which heat it is partly 

 sublimed. When heated to 160° C. it is decomposed, and 

 emits a smell resembling that of benzoic aether. It burns easily 

 with a large yellow flame, resembling that of alcohol, and emits 

 no smoke. It is little soluble in cold water, but so much so in 

 boiling as to be deposited in crystals on the cooling of the 

 liquid. In alcohol and aether it is very soluble, but it may be 

 precipitated from either solvent by water : it is deposited in 

 crystals on their evaporation. 



When heated with an aqueous solution of potash it is de- 

 composed with the evolution of ammonia, and the solution 

 becomes of a deep brown colour. With a solution of liquid 

 ammonia in the cold there is no action, but it is dissolved on 

 the application of heat, and is deposited unaltered on the 

 cooling of the liquid. Sulphuric acid dissolves it very readily 

 when assisted by a gentle heat; it is not in the least black- 

 ened ; it does not precipitate on the cooling of the liquid, but 

 water causes the precipitation of it in an apparently unaltered 

 state. 



The analyses conducted in the usual way gave the follow- 

 ing results. 



1st. 0'7902 of the combination gave r022 carbonic acid 

 and 0-360 water. 



2nd. 0-505 gave 0-658 carbonic acid and 0-227 water. 



1st. 0*7925 gave by decomposition at red heat by quick 

 lime 0-833 chloride of silver, equal to 25930 per cent, chlorine. 



2nd. 0-5245 gave 0-555 chloride of silver equal to 26*10 

 per cent, chlorine. 



The nitrogen was determined qualitatively. The carbonic 



