210 CYANOGEN COMPOUNDS. 



Miscible with water in all proportions. Exceedingly 

 poisonous. 



It can be easily detected by means of the following 

 reactions: If to a solution containing it potassa be 

 added, then a ferroso-ferric salt, and the whole acidified, 

 Prussian blue is precipitated; if to a solution con- 

 taining it yellow ammonium sulphide be added and 

 the excess of the sulphide evaporated, the residue ex- 

 hibits an intensely blood-red color on the addition of 

 a drop of iron sesquichloride. 



In an anhydrous condition it combines with dry 

 hydrochloric, -bromic, and -iodic acids, forming white, 

 crystalline, but very unstable compounds, which, 

 brought in contact with water, are instantaneously 

 resolved into ammonium chloride (bromide, iodide) and 

 formic acid. 



Decompositions. When kept for any length of time 

 it is decomposed, a brown body being deposited in the 

 vessel ; very small quantities of other acids prevent this. 

 Boiled with acids or alkalies, it is decomposed, forming 

 formic acid and ammonia, water being taken up. Nas- 

 cent hydrogen (zinc and sulphuric acid) converts it 

 into methylamine (p. 40). 



Forms metallic cyanides with bases. Combines also 

 with several chlorides. 



The compounds of cyanogen with alcohol radicles 

 (nitriles) are described in connection with the alcohols. 



Cyanogen chloride. ^ There are two polymeric 

 compounds of cyanogen with chlorine known. 



Liquid cyanogen chloride, CNC1, is produced by 

 the action of chlorine on metallic cyanides or dilute 

 cyanhydric acid. -Colorless, very mobile liquid ; boils 

 at 4-15,5 ; and congeals at 5 to 6. Heavier than 

 water. Preserved in sealed tubes, it is transformed 

 into solid cyanogen chloride. Combines with several 

 metallic chlorides. Alkalies decompose it, chlorides 

 and cyanates being formed. The so-called gaseous 

 cyanogen chloride does not appear to have a separate 



