124 PROCEEDINGS OF THE AMERICAN ACADEMY 



of cassiterite, and having a smell similar to that of vanillin, but not 

 identical with it. 



Summary of Results. 



The formula of curcumin is C^Jrl^fi^, as proved by analyses of cur- 

 cumin itself, of its potassium salts, and its parabrombenzyl ester. 



It is a phenol-carboxylic acid, as shown by the study of its salts. 

 Tlie presence of carboxyl is indicated by its power of driving carbonic 

 acid out of potassic and calcic carbonates, and by the decomposition of 

 its diethylester on boiling with potassic hydrate. It contains the 

 vanillin group, and therefore its formula, as far as we have determined 

 it, is : — 



HC (C5H5)COOH 

 I 



H-C " CH 



II I 



H-C / C-O-CH3 



c 



I 

 0-H 



We are at present engaged in the study of the group C5H5, and 

 propose to extend our investigations to rosocyaniu and the turmeric 

 oU. 



