° 


PRODUCTS OF DECOMPOSITION OF COMENIC ACID. 229 
6-475 grains dried at 250° gave 
2-520 ... sulphate of lime. 
Experiment. Calculation. 
—_———— 
Carbon, . A 40°83 41:14 C,, 72 
Hydrogen, c 1:94 ey al H, 3 
Oxygen, . : a 41:15 0, 72 
Eanes ee a 16-08 1600 CaO 28 
100-00 100-00 175 
Hence the composition of the salt dried at 250° is represented by the formula 
CaO HO, C,, H, 0,- 
The crystals contain seven equivalents water of crystallization. 
7-177 grains air-dry salt lost at 250° Fahr. 
1893... water. 
8-757 grains air-dry salt lost at 250° Fahr. 
2270... water. 
these numbers, when calculated for per-centage, give 
ile Il. Mean. 
26°37 25:92 26-15 
and 26°47 is that corresponding to the formula 
CaO, HO, C,, H, 0, +7 aq. 
Neutral Comenate of Lime.—This salt is obtained in the form of crystalline 
grains, when a solution of the acid ammonia salt, to which an excess of ammonia 
has been added, is poured into a solution of chloride of calcium. According to 
the state of dilution of the fluids employed, salts containing different amounts of 
water of crystallization are obtained, and the appearance of the product varies 
accordingly. They are all insoluble in water. The well-washed substance gave 
the following results; the lime being estimated as sulphate, because the salt 
when dried blows up in a cloud on ignition. 
{ 9-670 grains dried at 250° gave 


6:270 ... sulphate of lime. 
6-015 grains dried at 250° gave 
7-545 ... carbonic acid, and 
1-280 ... water. 
Experiment. Calculation. 
——E—— 
Carbon, . ‘ 34:20 33-96 Ci. 72 
Hydrogen, : 2°36 1-88 H, 4 
Oxygen, . : 8 27°75 0,5 80 
Lime, é : 26°59 26°41 2CaO 56 
100-00 100-00 212 
The formula of the salt, dried at 250°, is therefore 
2.Ca0, C,, H, 0, +2 H,. 
two equivalents of water being retained at this temperature. 
VOL. XX. PART II. 3Q 

