326 GLYCURONIC ACID 



of this precipitate with acids has its actual source in glycu- 

 ronic acid. A molecule of the latter breaks down into a 

 molecule of furfurol and C0 2 . The former may be weighed 

 after precipitation of the distillate with phloroglucin ; and 

 the C0 2 taken up in a potash apparatus and estimated. As 

 furfurol formation is also possible from the pentoses, but 

 the accompanying separation of carbonic acid is entirely 

 characteristic for glycuronic acid (from the carboxylic 

 group of which it arises) the method serves to determine 

 glycuronic acid in the presence of pentoses. 66 It is to be 

 expected now that we possess this method, our knowledge 

 of the role and significance of glycuronic acid in the economy 

 will advance more rapidly than has hitherto been the case. 



68 B. Tollens, Zeitschr. f. physiol. Chem., 61, 95, 1909; U. Lefevre and 

 B. Tollens, Ber. d. deutsch. chem. Ges., 40, 4513, 1908. 



