OF ARTS AND SCIENCES. 221 



If, however, we suppose that the salt retained two molecules of 

 water at 100°, the result agrees very well with the calculated per 

 cents. 



Calculated for Calculated for 



BaCioUs042ll20. Found. BaCioIIioOi2H.O. 



Barium 37,53 37.87 37.32 



But this supposition is, to say the least, improbable, as the calcium 

 salt loses its water easily at 100°; unfortunately, we did not have 

 enough of the acid to repeat the analysis of the barium salt. 



Properties, The apoturmeric acid separates from its solution in 

 boiling water as a white, rather stiff, wooly mass, which renders the 

 whole solid, if the solution was a strong one; it melts at 221°, and is 

 easily soluble in alcohol, ether, and boiling water; nearly insoluble in 

 cold water. 



Ammonic apoturmerate is not very freely soluble, and gives the 

 following characteristic precipitates : With plumbic acetate, white 

 flocculent ; with cupric sulphate, whitish green, — both soluble in an 

 excess of the precii^itant ; with mercurous nitrate, white flocks ; with 

 ferric chloride, yellowish white ; with argentic nitrate, a heavy white 

 precipitate, slightly soluble in boiling water. With the other common 

 reagents it gives no precipitates at all, or very slight white ones. 



Several attempts were made to oxidize the apoturmeric acid, but 

 they gave no satisfactory result. The acid was attacked only with 

 difficulty either by potassic permanganate or chromic anhydride, and 

 the only insoluble substance left after the oxidation was simply unde- 

 composed apoturmeric acid. In no case have we observed the forma- 

 tion of terephthalic acid from apoturmeric, or from carefully purified 

 turmeric acid ; but this acid has appeared when a calcic turmerate 

 containing the non-crystalline impurity was oxidized. We should 

 therefore ascribe the formation of terephthalic acid from turmerol by 

 violent oxidation rather to this substance than to the turmeric acid 

 formed ; but our experiments must be repeated on a larger scale before 

 we can consider this point finally settled. 



It is to be regretted that we were unable to settle definitely the 

 composition of the apoturmeric acid, as this would have thrown much 

 liglit on the constitution of turmeric acid ; as it is, it is not worth 

 while to advance any hypotheses on this subject. 



We may add one more observation in reference to turmerol, viz. 

 isobutylturmerol does not give an addition-product with bromine, but 

 there is formed with evolution of hydrobromic acid a most uninviting 

 unstable viscous oil. 



