Dr. Simpson on Cyanide of Ethylene and Succinic Acid. 67 



the formation of succinic acid in this way, it became of course neces- 

 sary to prepare the cyanide of ethylene. This body I obtained by 

 submitting bromide of ethylene to the action of cyanide of potassium. 



The process was thus conducted : — A mixture of two equivalents 

 of the cyanide and one of the bromide was introduced into a large 

 balloon, together with a considerable quantity of alcohol, sp. gr. "840, 

 and exposed to the temperature of a water-bath, a Liebig's condenser 

 having been previously attached to the balloon in such a manner as 

 to prevent the alcohol from distilling off the reacting ingredients. 

 As soon as all the cyanide of potassium had been converted into bro- 

 mide, the alcohol was separated and distilled. A semifluid residue 

 was thus obtained, which was filtered at the temperature of 100° 

 Cent. On treating the filtrate with a saturated solution of chloride of 

 calcium, a reddish oil rose to the surface, which was well washed with 

 ether, and exposed for some time to the temperature of 140°, in 

 order to remove any bromide of ethylene that might have escaped 

 the solvent action of the ether. This body proved, on analysis, to 

 be cyanide of ethylene. It was not, however, quite pure. There are 

 difficulties attending its complete purification which I have not yet 

 overcome. 



At the temperature of the air, cyanide of ethylene is a semisolid 

 crystalline mass of a brownish colour. It melts under 50° Cent. It 

 is very soluble in water and alcohol, and sparingly soluble in ether. 

 It cannot be distilled. Nevertheless it bears a tolerably high tem- 

 perature without sufferiug much decomposition. Heated with an 

 alcoholic solution of potash, it gives off ammonia. Treated with 

 nitric acid, it forms a body which crystallizes from alcohol in long 

 needles. This and some other reactions I am at present engaged in 

 studying. 



Preparation of Succinic Acid. — Bromide of ethylene and cyanide 

 of potassium were made to react upon each other in the same manner 

 as in the preparation of the cyanide of ethylene. As soon as the re- 

 action was complete, the alcohol was separated from the bromide of 

 potassium, some sticks of caustic potash were added to it, and the 

 whole heated for several days by means of a water-bath. Torrents of 

 ammoniawere given off on applying the heat. As soon as the evolution 

 of this gas had ceased, the alcohol was distilled off and the residue 

 treated with a considerable excess of hydrochloric acid. This was 

 then heated gently as long as acid vapours continued to be evolved, 

 digested with absolute alcohol, and filtered, and then the filtrate was 

 evaporated to dryness. The dry mass thus obtained was treated several 

 times with alcohol in a similar manner. The result of these repeated 

 digestions was then dissolved in water, and a few drops of a solution of 

 nitrate of silver were added to it, which occasioned a slight precipitate 

 of chloride of silver. This was separated by filtration, and the filtrate 

 was exactly neutralized with ammonia. On adding excess of nitrate of 

 silver to this, an abundant white precipitate was obtained, very soluble 

 in nitric acid and ammonia. This gave, on analysis, numbers agree- 

 ing very well with the composition of succinate of silver. The acid 

 itself possessed also all the properties of succinic acid. It sublimed 

 F 2 



