CHAP. X.] THE NERVOUS TISSUES. 439 



fusion ; their atoms are not in a state of chemical tension, but require for 

 vibration into permanent decomposing distances the influence of strong 

 external affinities, water and heat. 



" The lecithines, however, are in a state of great atomic tension, and 

 therefore slight external affinities or dissociating impulses suffice to effect 

 their decomposition. Such a slight impulse is the attraction of absolute 

 alcohol for their fatty acid radicles in the absence of external water. The 

 water given out by the alcohol in becoming ethylic ether serves to enable 

 the radicle of glycero-phosphoryle to become glycero-phosphoric acid, and 

 to remain in combination with the choline evolved 1 ." 



SECT. 5. NON-PHOSPHORIZED NITROGENOUS BODIES OF UNKNOWN 



CONSTITUTION. . 



Cerebrin (?) or Cerebrins (?). 



Miiller's ^ n ^ e J ear 1858 Miiller published an account of 



cerebrin. a non-phosphorized body which he had obtained from 



brain by the following process. The brain was pounded 

 up with baryta water to the consistence of a thin milk and then 

 boiled ; the precipitate which formed under these circumstances was 

 extracted with boiling alcohol: on cooling, the alcoholic solution 

 deposited an abundant precipitate. This was treated with ether 

 to separate cholesterin and fats, and then recrystallized from boiling 

 alcohol. The purified body thus obtained, which was termed cerebrin 

 by Miiller, possessed the following characters : it was a loose, 

 white, very light, powder, destitute of smell and taste, soluble in 

 boiling alcohol and ether, but insoluble in water, cold alcohol and 

 ether. Under the microscope the body presented the appearance of 

 small round balls 2 . Miiller published analyses of this body (only 

 two carbon determinations being given) and to it he ascribed the 

 formula C 34 H 33 N0 6 . 



The following are the results of the analyses of Miiller's cerebrin : 



Calculated. Found. 



(1) (2) 



C 68-23 68-35 68*56 



H 11-04 11-30 11-25 



N 4-68 4-69 4'53 



16-05 15-66 15-66 



That a body produced by the prolonged action of a solution of 

 boiling barium hydrate on so complex an organic mixture as brain 

 should be a definite proximate principle of the unaltered organ would 

 appear in the highest degree unlikely ; even more unlikely than 

 that it should be a definite principle at all. Yet, without any sufficient 

 proofs, the existence of Miiller's cerebrin has found favour with all 

 those who have doubted the existence of protagon, and, since the time 



1 Thudichum, Op. cit. p. 198. 



2 Miiller, "Ueber die chemischen Bestandtheile des Gehirns." Ann. d. Chem. 

 u. Pharm., Vol. cv. p. 361, 2 te Abth. 



