212 PROCEEDINGS OF THE AMERICAN ACADEMY 



with water, the yellowish-brown precipitate is washed until free from 

 acetic acid, and dried in vacuo. 



0.1710 gr. of substance gave 0.4178 gr. of carbonic dioxide and 

 0.0922 gr. of water. 



Calculated for CiaHigOj. Found. 



Carbon 66.G7 6G.G2 



Hydrogen 5.55 5.99 



Properties. A viscous brown mass without definite melting-point, 

 although it shrinks together at 58°-60°, but it does not become fully 

 liquid below 100°. It is soluble in alcohol and glacial acetic acid, 

 essentially insoluble in ligroine and carbonic disulphide, slightly solu- 

 ble in ether and in benzol ; but its solubility in the latter is greater 

 than that of curcumin. It dissolves in strong sulphuric acid with 

 a blood-red color like that produced by curcumin. Aqueous sodic 

 hydrate dissolves it, forming a red solution, which becomes decom- 

 posed, with the formation of ill-defined black products, when allowed 

 to stand exposed to the air ; a mixture of alcohol and sodic carbonate 

 was reddened instantly by the substance, showing that the acetyl group 

 had replaced the hydrogen of the phenol hydroxyl, as was to be 

 expected} that is, its formula would be 



C,H3(0'CIl3) (0C,H30)(CJI,C00H). 



As has been stated already,* the substance gave unsatisfoctory results 

 when submitted to oxidation with potassic permanganate. 



Diacetcurcumin. C^^l^^^iS^Mz^^f^i- ^^ ^ne occasion the process 

 described above yielded a yellow crystalline product instead of the 

 brown viscous raonacetcurcumin. The coming of the vacation inter- 

 rupted our work before we had succeeded in determining the conditions 

 on which the formation of this substance depends, the few experi- 

 ments wliich we had time to try giving invariably monacetcurcumin ; 

 we must therefore, for the present, confine ourselves to describing the 

 properties and analysis of the substance. After the removal of the 

 acetic anhydride and sodic acetate by treatment witli water, it was 

 purified by washing with alcohol and crystallization from glacial 

 acetic acid, dried at 100°, and analyzed. 



0.2230 gr. of substance gave 0.5348 gr. of carbonic dioxide and 

 0.1090 gr. of water. 



Calculated for CjjIIigOg. Found. 



Carbon G").45 Go. 39 



TTydrogen 5.45 5.43 



* These Proceedings, Vol. XVII. p. 123. 



