OP ARTS AND SCIENCES. 215 



not succeeded in proving anything about it definitely, we may be 

 allowed to state that our results can be explained by the assumptions 

 that the carboxyl is attached to the carbon atom next but one to the 

 benzol ring, and that in the remainder of the side-chain some of the 

 carbon atoms are united to form a ring. 



TURMEROL. 



In our first paper on this subject we mentioned that, although 

 turmerol is converted into terephthalic acid by treatment with an 

 excess of a hot solution of potassic permanganate, the same reagent 

 produces, when cold and not in excess, one or more apparently new 

 acids. In the following paper we describe our study of the product 

 of this reaction, a complex mixture of acids, from which we have suc- 

 ceeded in isolating two new acids, — one having the formula CuHj^Og, 

 which we propose to call turmeric acid, the other either CyoHj^^fi^ or 

 CjoHjoO^, to which we would give the name apoturmeric acid. 



In order to obtain this product, a little turmerol was allowed to 

 stand at ordinary temperatures with a moderately strong solution of 

 potassic permanganate until the latter was reduced. The operation 

 was carried on in large beakers, and the yield seemed to be better 

 when not more than 500 c.c. of permanganate solution were used in 

 each oxidation, than when larger quantities were employed ; with this 

 amount the action came to an end in about three days. After the 

 liquid had become colorless, the oxide of manganese and unaltered oil 

 were removed by filtration, and again treated with permanganate 

 solution ; this treatment being repeated until the permanganate ceased 

 to act, when it was found that the oxide of manganese was essentially 

 free from organic matter, and therefore that the entire product was 

 contained in the aqueous filtrate. The mixed filtrates from a number 

 of operations were then concentrated on the water-bath, acidified with 

 sulphuric acid, extracted several times with ether, and the extract, a 

 black tarry liquid, distilled with steam, when a yellow oil (A) passed 

 over with some difficulty ; this was mostly turmeric acid. The residue 

 in the flask (B) contained a tarry substance and apoturmeric acid, 

 which not infrequently separated in white crystals as the solution 

 cooled. 



Upon distilling with steam the solution left after extraction with 

 ether, it yielded a strongly acid distillate containing a little of the 

 yellow oily acid, from which it was freed in great part by extracting it 

 five times with ether. It was then boiled with baric carbonate to 

 convert it into a barium salt, which crystallized, after it had evapo- 



