ITS CHEMICAL COMPOSITION. 113 



It may be observed that Bence Jones* has made an elementary 

 analysis of the residuum which is left after boiling the brain in 

 alcohol, ether, and water, and found that its composition was the 

 same as that of albumen. It is scarcely necessary to remark that 

 in the present state of our knowledge, no conclusions can be 

 deduced from such analyses as these. 



The fats of the nervous substance can more readily be sub- 

 mitted on a large scale to accurate chemical investigation than any 

 other constituents of the nerve-fibres, but this very circumstance 

 has thrown extraordinary difficulties in the way of inquirers, which 

 have been increased from the fact that the chemical investigation 

 was not simultaneously associated with a careful microscopical 

 examination of the matters that were being chemically treated. 

 Whilst so distinguished a chemist as Couerbef has distinguished 

 a number of indistinctly characterised fats, as a cephalot, cerebrot, 

 stearoconnot, eleencephol, &c., a no less distinguished chemist, 

 Fremy, J arrived at very opposite results, which, although they threw 

 considerable light on this question, did not by any means exhaust 

 the subject in a chemical point of view. Gobley, as we have 

 already observed, in vol. i, p. 243, separated phosphate of glycerine 

 from the brain-fat. The following facts are almost the only ones 

 possessing any certainty which have been obtained from the investi- 

 gations hitherto made in relation to these fats (which were nearly 

 all extracted from the brain). According to Fremy, boiling alcohol 

 will extract from triturated cerebral matter olein and oleic and 

 margaric acids, and fats which are combined in part with soda, 

 potash, or lime ; on then digesting the residue with hot ether 

 cholesterin and cerebric and oleophosphoric acids are obtained in 

 solution. The separation of these two groups is not, however, so 

 perfect as might have been supposed from the above remarks ; for 

 a considerable amount of cerebric acid and cholesterin passes into 

 the alcoholic solution, whilst oleic and margaric acids are found in 

 the ethereal solution. 



Fremy obtained the cerebric acid tolerably pure, by again stir- 

 ring the ethereal extract of the brain with cold ether, from which a 

 white mass separated, which soon assumed a waxy character after 

 decantation of the ether on exposure to the air. The fatty acid 



* Ann. d. Ch. u. Pharm. Bd. 40, S. 68 ff. 

 t Ann. de Chim. et de Phys. 2 SeY., T. 56, p. 164-180. 

 J Journ. de Pharm. T. 26, p. 769-794, and Ann. de Chim. et de Phys., 

 3 S^r., T. 2, p. 463-488. 



Journ. de Chim. et de Phys. 3 SeY., T. 11, p. 409-417, et T. 12, p. 5-13. 

 VOL. III. I 



