585 



/ 



formula of salicylic acid, because this formula contains a hydroxyl- 



gronp in the nucleus next to the carboxylgroiip. 



jj A formula as proposed by Brunner ^) is 



C in accordance with the just mentioned pro- 



^ \ porties of the salicylic acid. 



HC C = 



HC C — C 



\ / \ 

 C H 



H 



= 

 OH 



Lactic acid, 

 CH, . CHOH . COOH 



lartaric acid, 



Malic acid, 

 COOH . CHOH . CH, . COOH 



Citric acid. 



COOH . CHOH . CHOH . COOH COOH.CH,. C(OH).(COOH)CH,COOH. 



The research of these four acids was quite in agreement with 

 their constitution-formula, in connection with my experiments described 

 before. 



Tn alkalic solution the alifatic alcohols, such as methylic alcohol 

 and aethylic alcohol, have no acidic properties. ') 



It could be expected that lactic, malic, tartaric, and citric acid 

 would behave as respectively one-, two-, two- and three-basic acid 

 in accordance with the presence of an equal number of carbqxyl- 

 groups. 



The referential experiments are united in table H. 



Hippuric acid and sulfanilic acid ') 

 C,H,CO.NH . CH,.COOH p.C«H,(NH,)S03H. 



Although about these compounds with certainty nothing could be 

 foretold in accordance with the neutral character of acetamide 

 (CH3 . CONHJ and urea (CO(NH),) in acidic and alkalic solution ') 

 it could be expected that the aminogroup of the benzoxylamino- 

 acetic acid would not enable this compound to fix hydrochloric acid 

 under the circumstances of my experiments. Therefore it might be 

 •supposed that hippuric acid in acidic solution behaves neutral, in 



1) Compare A. F. Holleman, Die direkte Einführung von Substituenten in den 

 Benzolkern; Leipzig, 1910, p. 180. 



2) Chemisch Weekblad 14, 119 (1917). 



') The used preparations were from the laboratory-collection. 

 *) These Proceedings, June 30, 1917. 



