244 HISTORY OF CHEMISTRY. [LECTURE XII. 



important parts were concerned)," 3 found the very important 

 result that glycerine can unite with acids in three different 

 proportions. Thus : 



Monostearine = i Glycerine + i Stearic acid - 2 Water 

 = C H S 0, + C 30 H 3r ,0 4 -2 HO 



[C = 6, = 8] 



Distearine = i Glycerine + 2 Stearic acid - 4 Water 



= C 6 H 8 6 + 2C 3t; H 36 4 -4 HO 



(In the paper 2 HO is given.) 

 Tristearine = i Glycerine -f 3 Stearic acid - 6 Water 



= C 6 H 8 6 + 3 C 36 H 36 4 -6 HO 



Monochlorhydrine= i Glycerine + i Hydrochloric 



acid - 2 Water 



- C C H 8 O (3 + HC1 - 2 HO 



Dichlorhydrine =i Glycerine + 2 Hydrochloric 



acid - 4 Water 



= C 6 H 8 O a + 2HC1 -4 HO 



Berthelot interprets these facts in the following manner : 

 " These facts show us that glycerine exhibits the same rela- 

 tion to alcohol that phosphoric ncid does to nitric acid. In 

 fact, whilst nitric acid "does not produce more than one series 

 of neutral salts, phosphoric acid gives rise to three distinct 

 series of neutral salts, the ordinary phosphates, the pyro- 

 phosphates, and the metaphosphates. These three series of 

 salts, when decomposed by powerful acids in presence of water, 

 reproduce one and the same phosphoric acid. 



" Likewise, whilst alcohol only produces one series of neu- 

 tral ethers, glycerine gives rise to three distinct series of neutral 

 compounds. These three series, on complete decomposition 

 in presence of water, reproduce one and the same substance, 

 glycerine." 



This comparison between glycerine and phosphoric acid on 

 the one hand, and alcohol and nitric acid on the other, is of 

 great importance, even although it is unfortunately to some 



63 Comptes Rendus. 38, 668 ; Ann. Chim. [3] 41, 216 ; Annalen. 88, 

 304 ; 92, 301, 



