28 ELECTROLYSIS AND ELECTROS 'YN THESIS 



of the acid salt. (Different behavior from glutaric 

 acid, in the case of which the formation of the acid 

 salt does not take place.) After a time the crystals 

 disapppear, the free acid being regenerated. In 

 alkaline solution also, the formation of the acid salt 

 occurs, after a longer period of electrolysis. Never- 

 theless the continuous, though limited, evolution of 

 carbon dioxide and carbon monoxide is a proof of 

 partial oxidation. 



Itaconic Acid. The concentrated solution of the 

 alkali salt electrolyzed by Aarland 1 gave a hydrocar- 

 bon isomeric with allylene, C 3 H 4 , which is said to 

 have the formula CH 2 = C = CH 2 . Along with this 

 compound, some propylene was formed, while a por- 

 tion of the acid was always regenerated. 



Citraconic Acid. 3 The concentrated solution of the 

 sodium salt, likewise electrolyzed by Aarland, yielded, 

 besides a hydrocarbon, C 3 H 4 , small traces of acrylic 

 and mesaconic acid. 



Mesaconic Acid, under the same conditions, gives 

 the same hydrocarbon and traces of acrylic and 

 itaconic acid. 



Malic Acid. The electrolysis of malic acid was per- 

 formed by Bourgoin* and Brester. 4 The free acid, 



1 Journ. prakt. Chem., [2] 6, 256. 



2 Journ. prakt. Chem., J, 142. 

 8 Bull. soc. chim., [2] 9, 427. 

 4 Jahresb. f. Chem., 1866, p. 87. 



