OF ARTS AND SCIENCES. 



turned black, and upon addition of water, a red precipitate was thrown 

 down, which was washed with water, dried, and analyzed, — 



I. 0.6652 g. of substance gave 0.7160 g. of CO2 and 0.1122 g. of 



up. 



0.3100 g. gave according to Carius 0.4125 g. of AgBr. 

 II. 0.3202 g. gave 0.3498 g. of CO^ and 0.0562 g. of HgO. 

 0.2786 g. gave 0.3730 g. of AgBr. 



The substance is red and amorphous ; it does not melt under a red 

 heat, but seems to be decomposed without melting. It is insoluble in 

 water, ligroiue, and benzol, very slightly soluble in alcohol and ether, 

 soluble in glacial acetic acid. Strong sulphuric acid has no action 

 upon it. It is vigorously acted on by boiling potassic hydrate, forming 

 a red solution, from which acids precipitate a black tarry body which 

 we were unable to purify ; two analyses of its sodium salt, however, 

 showed that it contained about the same percentage of oxygen as of 

 carbon, and that most of the bromine (all but 7 per cent) had been 

 removed, proving that the bromine in the original substance is all in 

 the side-chain. 



Action of Bromine on Curcumtn. 



We have obtained two bromine compounds of curcumin, one con- 

 taining four and the other seven atoms of bromine. 



Tetrabromide of Curcumin.^ Cj^Hj^Br^O^. When curcumin sus- 

 pended in carbonic disulphide is allowed to stand with an excess of 

 bromine for some hours, it is converted into a white substance, which 

 is left as the carbonic disulphide evaporates. The carbonic disulphide 

 can be replaced by glacial acetic acid, but in this case an excess of 

 bromine or the use of a large quantity of glacial acetic acid must be 

 avoided. The nature of this body could not be established satisfac- 

 torily by analysis, as it was more or less decomposed by all its sol- 

 vents, and therefore a thorough purification was impossible ; we have 

 obtained one fair analysis, however, of a sample washed with carbonic 

 disulphide. 



0.2375 g. of substance gave according to Carius 0.3180 g. of AgBr, — 



Calculated for CiiHuBrjO^. Found. 



Bromine 56.66 56.99 



