RELATIONS OF THE ORGANS TO ONE ANOTHER. 613 



perhaps in the same way as we found in the formation and breaking down 

 of glycogen in the liver that there was an indeterminable dependence upon 

 the nervous system. Unfortunately, in comparison with the countless 

 observations of pure physiology concerning the functions of the entire 

 nervous system, we have nothing from the physiological-chemical stand- 

 point. In fact, aside from the knowledge of a few constituents of the 

 nerve substance, we know very little indeed concerning the metabolism 

 taking place in nervous tissue. We will give here the results of the analysis 

 of the gray and white substances of the brain. 1 



The most striking value and this holds also for the composition of the 

 peripheral nervous system is the high phosphorus content of nervous 

 tissue. Phosphorus is evidently found in very different states of combina- 

 tion, at one time as nuclein, again in the form of a substance which is 

 known as protagon, 2 and at other times as lecithin. The latter occurs 

 partly free, and partly results from the hydrolysis of different products, 

 which have been isolated from nervous tissue, and have been designated 

 by different names; thus in the decomposition of protagon among the fatty 

 acids and other cleavage-products, the so-called cerebrin has been found. 

 Of the substances which have been isolated directly from the brain, cere- 

 bron has been best studied, and its constitution established by Thierfelder. 3 

 He obtained from it, by hydrolysis, cerebronic acid, sphingosine, and galac- 

 tose in the following proportions: cerebronic acid 48.13 per cent, sphin- 

 gosine 34.46 per cent, galactose 21.77 per cent. 



Cerebron has the empirical formula C48Hg 3 NO9. Its hydrolysis takes 

 place in accordance with the equation: 



2TT/^v PTT/^iPTT \m _1_ P TT A 



Ll2\J 1^25^50^3 ' yl 7*135^^2 ~r ^6^12^6 



Cerebronic acid Sphingosine Galactose 



Cerebron 



1 F. Baumstark: Z. physiol. Chem. 9, 145 (1885). 



2 Liebreich: Annal. 134, 29 (1865). 



3 H. Thierfelder and Emil Worner: Z. physiol. Chem. 30, 542 (1900). H. Thierfelder: 

 ibid. 43, 21 (1904), and 44, 366 (1905). 



