220 PROCEEDINGS OP THE AMERICAN ACADEMY 



but we have beeu unable to bring the black tarry acid or the yellow 

 buttery one into a state fit for analysis, and can only say that the 

 very ill-defined calcium salt of the former contained 1.69 per cent of 

 calcium, while the latter gaveou oxidation an acid melting near 180°, 

 which was not phthalic acid, and was formed in such small quantity 

 that we were unable to determine whether it was a [)urc substance 

 or only a mixture of apoturmeric acid with some impurity. 



Apoturmeric Acid. The white crystalline acid was separated from 

 its impurities by crystallization from boiling water, till it showed a 

 constant melting-point. The same acid is obtained by oxidizing calcic 

 turmerate with a hot solution of potassic permanganate, and a good 

 part of the substance used for analysis was prepared in this way ; the 

 yield, however, was so small, not over 10 per cent of the turmeric acid 

 used, that we have been unable to determine even its formula with 

 certainty, as will be seen from the following analyses. 



0.1138 gr. of substance gave 0.2582 gr. of carbonic dioxide and 

 0.0590 gr. of water. 



Calculated for C10H10O4. 



Carbon 61.86 



Hydrogen 5.15 



The calcium salt made by boiling the acid with calcic carbonate and 

 water gave the following results : — 



I. 0.2274 gr. of salt dried in vacuo lost 0.0304 gr. when heated to 

 100°. 

 II. 0.1390 gr. lost 0.0186 gr. when heated to 100°. 



Calculated for Found. Calculated for 



CaC,oU8042Il20. I. II. CaCioU,„042U;,0. 



Water 13.43 13.36 13.39 13.33 



0.1826 gr. gave 0.3370 gr. of carbonic dioxide, 0.0758 gr. of water, 

 and 0.1016 gr. of calcic sulphate. 



Calculated for Calculated for 



CaCioUjO*. Found. CaCjoIIioO,. 



Carbon 51.72 50.32 51.29 



Hydrogen 3.40 4.61 4.27 



Calcium 17.24 16.36 17.10 



The barium salt prepared like the calcium salt gave a result which 

 is not in harmony with the preceding. 



0.2704 gr. of salt dried at 100° gave 0.1742 gr. of baric sulphate. 



Calculated for Calculated for 



BaCioIIsO^. Found. BaCioIIioQ*- 



Barium 41.64 37.87 41.39 



