504 ROSENBLOOM AND KAHIST 



tion which is of value in the detection and isolation of the substance 

 from the urine. The lead salt melts at 214-215 C. (Hammarsten.) 



CH COOH 

 2 



kfeoion; cwcosurK 

 OH 



OH 

 Uroleuc'ic ^c 



CHHNHCOOH 



H^HNH 



That homogentisic acid has the formula ascribed to it above is proven 

 by the fact that three methods for its synthesis demonstrate its constitu- 

 tion. Baumann and Frankel were the first to prepare it artificially 

 from gentisic aldehyde (1-4-dioxybenzaldehyd) : 



