218 PROCEEDINGS OF THE AMERICAN ACADEMY 



Found. 

 Calculated for CnHj^Oj. I. 



Carbon 

 Hydrogen 



Properties. The turmeric acid, as at first precipitated, is an oil, 

 which gradually solidifies in long white branching needles, or crystal- 

 line masses with a faint smell like cocoanut ; freed from oil by press- 

 ing between filter-paper it melts at 34°-35° ; it is slightly soluble 

 in water, very freely in all the other common solvents except methyl- 

 alcohol, in which, however, it is readily soluble, so that it was found 

 impossible to crystallize it from this or any other solvent ; it distils 

 slowly with steam, and is a monobasic acid. When oxidized with a 

 hot solution of potassic permanganate, not in too great excess, it gives 

 the apoturmeric acid, which will be described later in this paper. 



Calcic Turmerate. Ca(CjiHj302)2. 3H2O. The preparation and puri- 

 fication of this salt have been described in connection with the manu- 

 facture of turmeric acid. For analysis it was dried, at first in vacuo, 

 and afterward at 100° or 110°, when several agreeing analyses gave 

 the percentage of calcium 10.78-11.13, whereas calcic turmerate con- 

 tains only 10.15 per cent of calcium. This led us to susjiect that the 

 salt had undergone a constant decomposition at this temperature, 

 which we were the more inclined to do, because at first it lost weight 

 very rapidly, but later the loss drop{)ed to a few milligrammes a day, 

 and more than a week of continuous heating was necessary to obtain 

 a constant weight, while at the same time the salt gradually became 

 brown and viscous. We have therefore calculated our results upon 

 the salt dried in vacuo, and these agree very well with the amount of 

 calcium in calcic turmerate containing three molecules of water of 

 crystallization. 

 I. 0.3131 gr. of substance dried in vacuo gave 0.0970 gr. of calcic 

 sulphate. 

 II. 0.2993 gr. gave 0.0912 gr. of calcic sulphate. 



Calculated for Found. 



Ca(0iiUi3O2)-.3Uj0. I. II. 



Calcium 8.93 9.11 8.96 



Properties. It forms spherical collections of white radiating needles 

 looking like chestnut-burs ; the purer the salt the more distinct are 

 the separate needles. When boiled with water it melts to a viscous 

 mass, which is then acted on by the water only very slowly ; it is 

 therefore advisable to dissolve it in the cold. 



7.8G1 gr. of the solution saturated at 1G° gave 0.0344 gr. of calcic 

 sulphate. Therefore a saturated solution at 1 6° contains 1.27 per cent of 



CaCC.jII^pjr 



