240 HALOID BASES AND SALTS. 



bicarbonate loses 1 atom of carbonic acid, and becomes converted 

 into a simple salt, which again acts on the fat in the above de- 

 scribed manner. 



Ammonia and its carbonate only form soaps after a more pro- 

 longed action. 



GLYCERINE. C 6 H 7 O 5 .HO. 



Chemical Relations. 



Properties. Glycerine is a faintly yellow fluid with an agreeable, 

 sweet taste ; it attracts water from the atmosphere, dissolves 

 readily in water and alcohol, but not in ether, and exerts no reaction 

 on vegetable colours. It dissolves alkalies and several of the 

 metallic oxides (for instance, oxide of lead) in large quantities ; in 

 a concentrated state, it admits of being distilled with only partial 

 decomposition, but when rapidly heated, it is entirely decomposed ; 

 if its watery solution be exposed to evaporation, decomposition 

 immediately commences : when heated in the air, it becomes in- 

 flammable, and burns with a blue flame. If heated with anhydrous 

 phosphorus in a tube from which fresh air is excluded, it yields 

 acrolein. If glycerine be dissolved in a large quantity of water, 

 mixed with yeast, and exposed to a temperature of between 20 

 and 30, it developes a small quantity of gas, and is converted 

 into metacetonic acid (C 5 H 7 O 5 -2HO = C 6 H 5 O 3 ; Redtenbacher.*) 

 Treated with spongy platinum, glycerine also becomes converted 

 into an acid (Dobereinerf). By concentrated nitric acid it is con- 

 verted into carbonic acid, oxalic acid, and water ; with hydrochloric 

 acid and peroxide of manganese, it yields a large quantity of formic 

 acid. 



Composition. In accordance with the above formula deduced 

 by PelouzeJ from his analyses of pure glycerine and its acid salts, 

 this substance consists of : 



Carbon 6 atoms .... 39'130 



Hydrogen 7 .... 7'609 



Oxygen 5 .... 43-478 



Water 1 .... 9'783 



100-000 

 The atomic weight of anhydrous glycerine =103 7*5. 



* Ann. d. Ch. u. Pharm. Bd. 57, S. 174-177- 

 t Journ. f. pr. Ch. Bd. 29, S. 451. 

 J Compt. rend. T.21, pp. 718-722. 



