CHAP. X.] THE NERVOUS TISSUES. 441 



a cerebrin-like body, which agrees fairly in so far as the C and II 

 with Geoghegan's body. The nitrogen has not yet been determined. 



C. in 100 parts 68'95 



H. 1132 



(3) In addition to protagon, and other phosphorized matters, 

 there is always extracted from brain by alcohol at 45, a very con- 

 siderable quantity of a body, which, in order to distinguish it, the author 

 provisionally termed pseudo-cerebrin. This body is less soluble in 

 80 p. c. alcohol at 45 than protagon, so that on subjecting impure 

 protagon to repeated crystallization from 80 p.c. alcohol there accumu- 

 lated residues consisting of the cerebrin-like body. The latter is a 

 white, pulverulent body, very unlike protagon to the naked eye and 

 separating under the microscope in the form of very large nodular 

 masses. After repeated recry>stallization from alcohol it was found to 

 be practically free from phosphorus (containing only 0*08 p. c.). 



On analysis this body has given results which are not widely differ- 

 ent from those of Geoghegan, though they are sufficiently discrepant 

 to render it certain that the substances analysed by that observer 

 and himself were not identical. Whilst the author would refrain from 

 speaking with confidence of the absolute purity of ' pseudo-cerebrin! 

 he has, however, no hesitation in asserting that Geoghegan's substance, 

 from the method of preparation, is necessarily a mixture of the so- 

 called pseudo-cerebrin just referred to with a 'cerebrin' obtained by 

 the action of barium hydrate on protagon and therefore much more 

 impure than the body now provisionally described by the term of 

 pseudo-cerebrin. 



Analyses of ' pseudo-cerebrin' found by the Author to accomnany Protagon. 



(1) (2) (3) (4) Mean. 



C 6897 68-95 69*01 68'67 68-89 



H 11-7 11-17 11-60 12-10 11-87 



N 176 1-95 1-64 2-01 1'83 



O. 17-41 



100-00 



From the above analyses the author deduces for ' pseudo-cerebrin' 

 the empirical formula C^H^NOg. 



It would therefore appear to the author that whilst protagon 

 cannot be separated by the action of solvents into a non-phosphorized 

 cerebrin and a phosphorized body, yet such non-phosphorized bodies 

 exist by its side in the brain, and can be obtained from protagon by 

 the action of caustic baryta. 



By the action of concentrated sulphuric acid on 

 gan's^e- 6 " cerebrin, this author has obtained a body to which he 

 searches in ascribes the formula C 22 H 42 O 5 and believes to be a 

 the decompo- derivative of cetyl-alcohol, and which he terms Cetylid. 

 sition of cere- Q n f us i on w ith caustic potash this body evolves a 

 an. Cetylid. mixture of QJJ^ H and Nj whilat p a l m iti c ac id is 



formed ; a portion of the N is left in the form of an ammoniacal salt. 



