OP ARTS AND SCIENCES. 219 



The salt is also soluble iu alcohol, and is decomposed by a heat of 

 100^-110°, as already stated. 



The behavior of a solution of the calcium salt with various reagents 

 was also studied, and it was found to give a white flocculent precipi- 

 tate with aluminic chloride ; a similar reddish-brown precipitate with 

 ferric chloride ; heavy white precipitates with mercurous or plumbic 

 salts, the plumbic salt melting mider boiling water and forming, when 

 prepared in quantity, an uninviting yellowish viscous mass ; cupric 

 nitrate produced pale-blue flocks, and argentic nitrate a heavy white 

 precipitate somewhat soluble in water; the other common reagents 

 gave no characteristic precipitates. 



An attempt was made to prepare and analyze the silver salt, but we 

 did not succeed in purifying it, since its solubility in water is so great 

 that the impurities could not be removed by washing without using 

 a larger amount of substance than was at our disposal ; and it was 

 impossible to recrystallize it from water, as its solutions decomposed 

 with great ease. An imperfectly washed specimen gave a result which 

 approaches that required by theory. 



0.1932 gr. of the salt dried in vacuo gave 0.0750 gr. of silver. 



Calculated for AgCuHijOj. Found. 



Silver 37.89 38.82 



The barium salt resembled the calcium salt iu that it formed little 

 balls of radiating needles, but showed a much greater tendency 

 to separate in a viscous state, so that it was hard to obtain it 

 crystallized. 



The behavior of the zinc salt is very characteristic; when a solution 

 of it is prepared by boiling the acid with water and zincic oxide, 

 allowing the liquid to cool, and filtering, the clear solution thus 

 obtained becomes turbid, when warmed even to temperatures far 

 below the boiling-point, but clears up again as the liquid cools. The 

 salt could be obtained only as a viscous mass. 



B. Study of the Residue from Distillation with Steam,. 



The flask-residue, after the turmeric acid had been distilled off with 

 steam, contained a black tarry substance, and not infrequently a white 

 crystalline acid, which can be separated from the tar by treatment 

 with boiling water. On extracting with ether the aqueous mother- 

 liquor, from which the white acid had crystallized, a third substance, 

 yellow and buttery, was obtained. All these substances are acids, 



