GLYCERIN. 173 



Acetin, C 3 IP j Q j^jpo is formed by continued 

 heating of glacial acetic acid with glycerin to 100. 

 A liquid with an ethereal odor ; miscible with little 

 water. 



r r\TT 



Diacetin, C 3 H 5 , 2 2 is formed 



heating is carried to 200. Neutral liquid, boiling at 

 280. 



Triacetin, C 3 IP(O.C 2 H 3 0) 3 ,by heating diacetin with 

 an excess of glacial acetic acid to 250. Is contained 

 in the oil of Evonymus Europeans. Liquid, boiling at 

 268. 



Trilaurin, C 3 H 5 (O.C 12 H 23 0) 3 , occurs in the fruit of 

 laurel, in butter of cocoa, and in pichurim beans ; and 

 can be obtained by boiling these with alcohol. Color 

 less, small needles, which fuse at 44-46. 



Tripalmitin, C 3 IP(O.C 16 H 31 0) 3 . Contained in most 

 fats, particularly abundantly in palm-oil. From this 

 it can be obtained pure by strong pressure, repeated 

 washing of the residue with alcohol, and recrystalliza- 

 tion of the portion insoluble in alcohol from ether. 

 Artificially, it is obtained by heating glycerin with an 

 excess of palmitic acid to 270 for several hours. 

 Small colorless crystals, in alcohol, even at the boiling 

 temperature, but slightly soluble; easily soluble in 

 ether. 



Tristearin, C 3 IP(O.C 18 H 35 0) 3 . It can be obtained 

 pure from solid fats by repeatedly extracting them with 

 cold ether, pressing the residue, and crystallizing 

 several times from ether. Artifically, it can be pre 

 pared like palmitin. It crystallizes in laminae, which 

 fuse at 66.5. The fusing point is, however, changed 

 when the substance is heated only a few degrees above 

 it and then allowed to solidify. 



16* 



