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



0-341 grm. of the same substance lost at 140° C. 0-022 grm. 

 water. Consequently 100 parts would lose 6-4 parts of water. 



If we assume that one atom of water II-O escapes from the 

 compound 2 (C^H5ZnO'*) + H20, the loss ought to be 6-1 per 

 cent. 



0-214 grm. dried at 140° C, furnished 0-206 carbonic acid and 

 0-075 grm. water. 



0-4075 grm. of the same substance furnished 0-121 grm. 

 oxide of zinc. 



100 parts contain, according to these determinations, — 

 Carbon .... 26-23 

 Hydrogen. . . . 3-89 



Zinc 23-83 



The formula C^ H^ ZuO^ corresponds to — 



Carbon ... 3 36 26-16 



Hydrogen . . 5 5 3-63 



Zinc .... 1 32-6 23-69 



Oxygen ... 4 64 



137-6 



The substance, the analysis of which has just been communi- 

 cated, was now exposed to a higher temperature thau 140° C. 



0-341 grm., dried in vacuo, was kept for some time at 140° C, 

 and subsequently for one hour at 170° C. The gly cerate of 

 zinc thus treated had lost 0-059 grm. in weight, and was partly 

 decomposed. On its then being treated with boiling water it 

 did not dissolve completely, but left a brown residue. The fil- 

 trate from the latter could be evaporated to the consistency of 

 syrup without yielding crystals. When evaporated to dryness 

 in vacuo, a mass, consisting evidently of two substances, was 

 obtained. Consequently the formula of the anhydrous zinc-salt 

 isCSH^ZnO". 



Glycerate of Lead, Q^W'VhO\ 



may be obtained easily by the following method : — To a diluted 

 and warm solution of glyceric acid pure oxide of lead is gradually 

 added in small portions, till the acid reaction of the liquid is 

 nearly destroyed, and the filtered solution concentrated by eva- 

 poration on the water-bath. If it be now allowed to stand in a 

 cold place for some time, a hard crystalline crust of the above 

 substance is formed on the sides of the evaporating basin. If the 

 glyceric acid employed be too concenti-ated, the lead compound 

 separates immediately after the addition of the oxide, as a white 

 crystalline powder. 



Glycerate of lead dissolves with difficulty in cold, but pretty 

 easily in hot water: the solution does not alter blue litmus- 



