DISSOCIATION OF LECITHIN 



185 



TABLE C 



With Dietrich and Hegel, it is difficult not to be forced to 

 the conclusion that the lecithins with their glycerophosphoric 

 acid are intimately associated with and derived from nuclear 

 material with its glycerophosphoric acid ; and that the myelin- 

 like bodies in the cytoplasm are of the nature of lecithins, which 

 lecithins undergo subsequent dissociation. My present view — 

 which I admit is subject to revision — is that it is not the leci- 

 thins proper that afford the doubly refractive globules, but the 

 products of their dissociation and more particularly those of 

 the di-oleo-lecithins, and of the interaction between the cholin and 

 the cholesterin and the oleic acid. For it must be kept in mind 

 that oleic is a singularly weak acid, that its compounds are 

 singularly liable to hydrolysis with liberation of free oleic acid. 

 As a matter of fact, lecithin warmed with cholesterin affords 

 with water or dilute glycerin exquisite doubly refractive myelin 

 figures ; as, again, by acting on pure lecithin (Riedel's lecithol) 

 with alkalies, the doubly refractive globules can be gained. 

 Schenck, indeed, lays down that the salts (soaps) of oleic acid 

 never exist in a chemically pure state ; there is always some 

 water and alkali mixed, free oleic acid, and free alkali. This 

 natural impurity is very possibly a feature of importance in 

 the myelin formation by members of this group. 



Let me, in conclusion, state that I have not brought up this 

 matter of the doubly refractive myelin globules as a method 

 by which the existence of myelin in the tissues of the body 

 can surely be recognized. That is by no means the case. The 

 formation of these globules is no constant reaction. What I 

 would emphasize is that under certain conditions, not always 

 easily obtainable, Virchow's myelin can be shown to possess 

 this very characteristic reaction, and that so, the myelin figures 

 and myelin globules in the organism must be regarded as of 

 fatty nature, and more, that these belong to that remarkable 



