2 PKOCEEDINGS OF THE AMERICAN ACADEMY 



chloric acid, the fawn-colored precipitate thus obtained washed till 

 free from acid, and dried in vacuo. A combustion gave the following 

 results : — 



0.2290 g. of substance gave 0.5678 g. of CO2 and 0.1312 g. of Hp. 



Calculated for C^fiyfi^. Found. 



Carbon 67.74 67.63 



Hydrogen 6.49 6.36 



Properties. It forms a brownish white powder melting in the neigh- 

 borhood of 100°, but with no definite melting-point; it is insoluble 

 in water, freely soluble in alcohol and glacial acetic acid, slightly in 

 ether, and insoluble in ligroine and benzol. Strong sulphuric acid 

 dissolves it with a reddish-brown color, very different from the purple 

 produced by curcumin. Sodic hydrate dissolves it on warming, and 

 so does sodic carbonate ; but the latter solution becomes turbid, and 

 throws down a brownish precipitate on cooling. 



The adilition of hydrogen to curcumin by sodium amalgam and 

 dilute alcohol is a tedious process occupying more than a week and 

 giving a very bad yield, the product being frequently accompanied by 

 a viscous substance, probably formed by the action of air on the alka- 

 line solution of the hydride. A much better method of adding hydro- 

 gen to curcumin consisted in treatingf it with zinc dust and acetic 

 acid, although in this case tlie hydride at first produced was further 

 modified in the course of the reaction. 



Anhydride of Curcumin Dihydride, (C^^^^O^.,0. Curcumin was 

 warmed with acetic acid of 85 per cent and a large quantity of zinc dust, 

 the temperature being kept below the boiling-point of the acetic acid. 

 After some hours the yellow color of the solution had become replaced 

 by a dark brown, and if then a little of the substance gave a yellow 

 instead of a red color with sodic hydrate, the heating was discontinued, 

 and the liquid filtered into water, which precipitated fawn-colored 

 flocks similar to those of the preceding compound. After we had 

 satisfied ourselves that it was impossible to crystallize the substance, 

 we purified it by resolution in glacial acetic acid and precipitation 

 with water ; but even this treatment did not remove the whole of the 

 zinc salt, as was shown by the appearance of a slight ash on combus- 

 tion. This has been subtracted from the weight of the substance 

 taken in calculating the percentages. 



The same substance was obtained when curcumin was heated with 

 zinc dust and a solution of ammonic hydrate. The combustion marked 

 III. was of a product made in this way : — 



