THE COMPOSITION OF SO CALLED ELŒOMARGARIC A.CID. ;$ 



appear, therefore, to be oleic acid and a solid acid having the formula 

 ( '. J I ...( )... stereoisomeric with linolic acid, whilst the presence in any 

 considerable quantity of the acid ( ! 18 1 [ 30 ( )., is excluded. The determina- 

 tion of the neutralisation number of the solid acid by means of care- 

 fully standardised alkali shows, moreover, that this corresponds with 

 the formula C 18 H 33 3 rather than with C 17 II : , 2 0.,. 



No attempt was made to repeat the analyses of the solid acid' 

 since no definite information was to be expected from the result on 

 account of the small difference in the percentage amounts of carbon 

 and hydrogen required by the formulae CjgHggO,, C 18 H 30 O 2 , and Cj 7 H 30 O 3 . 

 The silver and lead salts of the solid acid were prepared, but they are 

 both amorphous and very readily oxidisable in the air, even more so 

 than the acid itself, so that, although silver estimations were made 1 

 no concordant results could he obtained. The reduction of the solid 

 unsaturated acid by heating in a sealed tube with fuming hydriodic 

 acid and red phosphorus has been tried, but the experiments in this 

 direction have not yet been brought to a successful issue. 



Experimental. 



Saponification of the Oil. — To 30 grams of the cold-drawn oil 



contained in a flask were added 100 c.c. of alcohol and 15 grams of 

 caustic potash, dissolved in 60 c.c. of water. The flask was connect- 

 ed with an inverted condenser and the contents gently boiled on the 

 water-bath for about two hours. Hydrochloric acid was then added, 

 in slight excess, to the clear alcoholic solution, when a brown oil 

 separated, changing into a crystalline mass on cooling. By recrys- 

 tallisation from alcohol, the solid acid was obtained in the form of 

 white, lustrous lamina' melting at 43 — 44° (Cloëz gives the melting 

 point of the solid acid as 48°, whilst De Negri and Sburlati give it as 

 43*8°). 



