THE COMPOSITION OF SO-CALLED ELiEOMARGARIC ACID. 5 



= 348, melting point 173°). The results of its combution were as 



follows : 



0.1329 gave 0.3015 Co s and 0.1214 H 2 0. C=61.87; H=10.16. 

 C ]8 H 82 (OH)A requires C=62.07; H=10.34. 



(2). Another crude acid (yield one-fourth of the above acid) 

 which, on evaporating the etherial extract to a small bulk and cool- 

 ing, was obtained in a crystalline state. After recrystallisation from 

 alcohol it melted at 126°, and had the molecular weight 317.3 

 (dihydroxystearic acid, C ]8 H 34 (OI4) 2 2 = 316, melting point 136°). 

 Probably, therefore, this substance is impure dihydroxystearic acid. 



No characteristic crystals of either linusic acid or isolinusic acid, 

 C ]8 H 30 (OH) 6 O 2 , could be observed. 



Neutralisation number of the solid acid. — The pure recrystallised 

 solid acid (m.p. 43 — 44) from the oil was dried over sulphuric acid in 

 an atmosphere of carbon dioxide ; a weighed quantity was dissolved 

 in neutralised alcohol and titrated with 0.05 6 8- normal sodium 

 hydroxide solution, using Phenolphthalein as indicator. The mole- 

 cular weight found were 280. G, 277.1, and 280.9. Titrations with 

 standard barium hydroxide solution gave the numbers 283.1 and 

 280.7, the mean of all the determinations being 280.5, whilst 

 C J8 H 32 O 2 =280. 



Summary of tlie Results. 



1. The principal organic acids of the oil of Elœococca vemieia 

 are a solid acid, m. p. 43 — 44°, and ordinary oleic acid, the former 

 predominating. 



2. The solid acid, which Cloëz named elœomargaric acid, and for 

 which Maquenne recently proposed the name a-elccostearic acid } has 

 the composition C 18 H 32 2 , and not C 17 H 32 2 , as calculated by Cloëz, or 

 C l8 H 30 O 2 , as given by Maquenne. 



