43 REPORT— 1867. 



oue molecule of eacli of tlio parent bodies, from the fact that it gives lactic acid 

 with hydrochloric acid^ and that it separates by the action of heat into prussic acid 

 and ordinary aldehj'dc, and not into a polymer of aldehyde such as elaldehyde or 

 paraldehyde. 



The cyauhydrate of aldehyde is, in our opinion, a very striking example of an 

 organic compound which the temperatm'e of vaporization decomposes, and the 

 prolonged action of time reconstructs. 



On the Formation of Succinic Acid from Chloride of Ethylidene. 

 By Maxwell Simpson, M.D., F.li.S. 



Some years ago * I ascertained that when bromide of ethylene is successively 

 treated with cyanide of potassium and caurtic potash, ordinary succinic acid is 

 formed. This reaction has since been confirmed by M. Geuther t, who, however, 

 emplo3^ed chloride instead of bromide of ethylene. 



It occurred to me that it would be interesting to ascertain v.^hether the chloride 

 of eth3didene would, when subjected to the same treatment, produce the same or 

 an isomeric acid. One would naturally e>:pect the latter result, seeing that the 

 constitution of the chloride of ethylidene is different from that of the chloride of 

 ethylene. The following formulce will make this intelligible, and show the pro- 

 bable constitution of the isomeric acid : — 



CH,C1 Clifiy CHaCCOOII)' 



CII2CI ClljiCy CII,,(COOH)' 



Chloride of Cyanide of Ordinary 



ethylene. ethylene. succinic acid. 



CH3 CH3 CII, 



CHCI2 CHCy, 011(00011), 



Chloride of Cyanide of Isomeric acid, 



ethylidene. ethylidene. 



It is to be observed that in the transformation of cyanide of ethylene into ordi- 

 nary succinic acid, the group OOOH takes the place of each eqiuvalent of cyanogen. 

 In the transformation of cj'auide of ethylidene, it is to be supposed • that the 

 cyanogen is replaced in a similar manner, with the formation of an isomeric acid. 

 In order to determine this point, 1 made the following experiments : — 

 A mixture of oue equivalent of pure chloride of ethyle chlore, which is ideutical 

 with the chloride of ethylidene, two equivalents of pm'e cj'anide of potassium, and 

 a large quantity of alcohol was exposed in a sealed matrass for twenty-seven hours 

 to a temperatui'e ranging between 100° and 180° Cent. I had previously ascer- 

 tained that a high temperature was necessary in order to produce a reaction. At 

 the expiration of the above-mentioned time the matrass v/ns opened and its con- 

 tents filtered. The filtered liquor was then treated with solid potash, and after- 

 wards exposed to the temperatm-e of a water-bath till ammonia ceased to be 

 evolved. When this was obs-'rved, the alcohol was distilled off, and nitric acid 

 added in excess to the residue. Finally, this was evaporated to dryness at a low 

 temperatm-e, and the liberated organic acid taken up by alcohol. Ey dissolving 

 in absolute alcohol, and crystallizing from water, the acid was obtained qiute pure. 

 The quantity of acid formed was not large. Dried at 100° Cent., it gave the 

 following numbers on analysis : — 



Theory. 

 Succinic acid. Experiment. 



40-86 

 5-55 



}> » 



* Philosophical Transactions for 1861. 



t Annalen der Cliemie and Pharmacie. Band, cts. S. -G8. 



