296 THE FATTY ACIDS OF BRAIN LIPOIDS. I., 



stearic acid without oxidation. As regai-d.s the fatty acids of 

 protagon, reliable data are wanting. 



Although, however, much labour has been expended on lipoids, 

 most of it has drifted in the wrong direction of examining b}'^ 

 qualitative means substances ill-characterised and obtained by 

 chance solvents. No problem in biochemistry could be more 

 definite than that of determining the proximate constituents of 

 various organs, and these must surely be known before we are 

 concerned with the more complex structures into which they 

 may be built. The most obvious step in advancing our know- 

 ledge of the lipoids is to examine the fatty acids. Hartley* has 

 rightly entered the field in his examination of the fats of viscera. 

 This author has shown that his results apply to a great extent 

 to the lipoids. In the case of the brain, however, what is said 

 of the fatty acids applies chiefly to those combined as lipoids, the 

 quantity of free fat being negligible. 



On the following page is given in tabulated form a review of 

 our knowledge of the fatty acid radicles of lipoids up to the 

 present time. 



The object of this work is to examine the fatty acids of brain 

 lipoids. Part i. deals with the total fatty acids as obtained by 

 direct saponification of the brain. 



Liter AT DRE. 



(1) DiAKONOW— Cbl. Med. Wissenschaft, 1868. 



(2) Strecker— Annalen der Chem. Pharm. Bd.cxlviii., s.77, 186. 



(3) Thcdichum— Chem. Konst. der Gehirns der Menschen u. Tieren, 



Tubingen, 1909. 



(4) Henriques & Hansen— Skandr. Aich. fiir Physiol. Bd.xiv. p 3, 19Co. 



(5) Cousin— Comptes Rendus Soc. Biol, tome 55, 1903. 



(6; ERLAND.SEN— H. S. Zt. Physiol. Chem. Bd. 54, ss.71, 83, 104, 1907. 



(7) Koch— Zt. Physiol. Chem. Bd.36. 



(8) Zuelzer— lb. Bd. 27, s.2f.9, 1899. 



(9) Baskoff— ib. Bd. 55, s.39o, 1908. 



(10) KossEL u. Freytag— ib. Bd. 17, s.431, 1893. 



* Hartley, Journal of Physiology, Vol. xxviii. p. 353(1909). 



