203 Dr. Debus on the Action of Nitric Acid on Glycerine. 



grm. water. Consequently 100 parts contain — 



I. II. Theoiy. 



Water 12-12 12-18 125 



and the formula for the anhydrous compound = C^ H^ CaO*. 



In order to ascertain if more than one atom of water could be 

 expelled from glycerate of lime, a certain quantity of it, dried 

 at the ordinary temperature, was kept for a few hours at about 

 175° C. In consequence of this high temperature the sub- 

 stance increased considerably in bulk, perhaps twenty times more 

 than its original volume, and was partly decomposed. The 

 loss in weight was scarcely 2 per cent, more than corresponds to 

 one atom of water. Consequently no more water can be expelled 

 by application of heat from C^ H^ CaO''. Glycerate of lime 

 which has been heated just to the point at which decomposition 

 takes place, is extremely hygroscopic. Some of it thrown into 

 a beaker containing only a few drops of water, disappeared as by 

 magic, forming a brown syrupy solution. After the latter had 

 been standing for a few days it had become one solid mass of 

 crystals, the shape and properties of which were the same as 

 those of C^ H^ CaO'*+ H^O. From these experiments it appears 

 that glycerate of lime can exist in two modifications : one ex- 

 tremely hygroscopic, and soluble in very little water, the other 

 less soluble in water. I have made similar observations with the 

 zinc-salt. 



Biglycerate of lime does not appear to exist. From 3'622 

 grms. of glycerate of lime, half the lime was precipitated by 

 0-798 grm. of oxalic acid, and the filtrate from the precipitate 

 evaporated to the consistency of strong syrup and allowed to 

 stand in the exsiccator for some days. The crystals formed were 

 placed on filtering-paper and dried in vacuo. 



0-370 grm. lost at 140° C. 0-042 grm. water. 



0-692 grm., dissolved in water and precipitated with oxalate 

 of ammonia, gave 0"238 grm. carbonate of lime. 



In 100 parts : — 



Found. Theoi'v. 



• O'H'CaO^ + irO. 



Water . . . 11-35 12-5 



Calcium . . . 13-7 13-98 



These numbers correspond without doubt to the neutral salt. 

 The acid mother-liquor did not yield any crystals after standing 

 many days. 



Glycerate of Ammonia, C^ H^ (NH") 0^ 



This substance was obtained by precipitating glycerate of 

 Jime with its equivalent quantity of oxalate of ammonia, an^ 



