430 LECITHIN. [BOOK 



LECITHIN. 



Besides the nervous tissues, there are others in which organic 

 phosphorized ingredients occur in considerable proportions ; these are 

 found in large quantities in the ovum, in spermatozoa, etc. 



The first satisfactory study of the phosphorized organic bodies 

 was made by Gobley *, who described under the name of Lecithine 

 a viscous proximate principle which he had separated from the eggs 

 of the carp. This body was entirely soluble in ether, soluble with 

 difficulty in cold, but readily in hot alcohol, from which it was 

 deposited on cooling. Gobley 2 found that this body, when ignited, 

 yielded an ash possessed of a strong acid reaction, owing to the 

 presence of phosphoric acid. He further shewed that when decomposed 

 with acids or alkalies, his lecithin yielded glycerin-phosphoric acid 

 and fatty acids, amongst which he cited oleic and margaric. Besides 

 lecithin, Gobley separated, by a process wjiich would certainly cause 

 decomposition of any complex proximate principle, a body which 

 he termed Cerebrin, which contained Q'43 p.c. of phosphorus. 



In researches on the brain which were anterior to his most mature 

 investigations on lecithin from eggs, Gobley arrived at the conclusion 

 that the phosphorized matter of the brain resembles, if it be not iden- 

 tical with, that obtained from eggs, and this view of Gobley's is the 

 one which has commended itself almost universally to physiological 

 chemists. 



After the publication of Liebreich's memoir on Protagon attention 

 was again directed to the phosphorized proximate principles of the 

 body, it being doubtless surmised that the well-defined protagon 

 would be discovered where earlier observers had found less sharply 

 characterized bodies. This surmise was, however, soon disproved. 



In a paper published in Hoppe-Seyler's Untersuchungen, by one 

 of his own pupils, Parke 3 , " On the Chemical Composition of the 

 Yolk of Egg," in which the amount of protagon present was calculated 

 on Liebreich's data from the amount of phosphorus found in the 

 alcoholic extract of the yolk of egg, the observation was made that, 

 by calculation, more protagon was found than corresponded to the 

 whole weight of the alcohol extract. 



In a paper immediately succeeding that of Parke's, Hoppe- 

 Seyler 4 clearly expressed his conviction that the yolk of egg contains 

 no protagon but lecithin, this being the name which Gobley had 

 given to the chief phosphorized constituent of the yolk. He further 

 stated, that experiments made in his laboratory by Herr Jiidell had 



1 Gobley, Journal de Chimie etPharmacie, Vol. xvii. (1850) p. 401 : Vol. xvm. (1850) 

 107. 



2 Gobley, Journ. de Pharm. et Chimie, Vol. xi. (1847) p. 409, and xii. (1847) 1. 



3 Parke, "Ueber die chemisette Constitution des Eidotters," Med.-chem. Unter- 

 suchungen, Heft 2, p. 213. 



4 Hoppe-Seyler, " Ueber das Vitellin, Icbthin und ihre Beziehung zu den Eiweiss- 

 Btoffen." Hed.-chem. Untersuchungen, Heft 2, p. 215. 



