1879.] 



On Liebreiclis Protagon in the Brain. 



151 



I. "On the Existence of Liebreich's Protagon in the Brain/* 

 By Professor Arthur Gamgee, M.D., F.R.S., Owens Col- 

 lege, Manchester, and Ernst Blankenhorn, Ph.D. Re- 

 ceived April 29, 1879. 



In the year 1865, Dr. Oscar Liebreich published an important 

 paper* npon a new proximate principle which he had separated from 

 the brain. Unlike the nnmerons bodies, possessed of ill-defined pro- 

 perties which had, by different writers, received the names of 

 cerebrin, cerebric acid, lecithine, or phosphorized fats, this new body 

 conld be extracted by an easy process in a state of pnrity, and 

 to it, probably as indicating it as the first definitively ascertained 

 specific constitnent of brain, Liebreich ascribed the name of Protagon 

 (7r/)WTa709, leading in advance). 



The substance was obtained by the following process. An animal 

 was bled to death from the carotid, and a stream of water was passed 

 through the vessels of the head, so as to wash the blood out. The 

 brain, freed from its membranes, was then pounded in a mortar and 

 shaken in a flask with ether and water at 0° C. It was allowed to 

 stand at a temperature of 0°, until the ether had separated, and the 

 treatment with ether again and again repeated. 



The brain matter having been separated by filtration from ether 

 and water, was digested with 85 per cent, alcohol, at a temperature of 

 45° C. The fluid was filtered hot and allowed to cool at 0° C. A 

 flocculent precipitate then separated, which was collected on a filter 

 and treated with cold ether, until it ceased to dissolve cholesterin. 

 The insoluble mass was dried in vacuo, and dissolved in spirit at 

 45° C. The alcoholic solution was filtered and allowed to cool very 

 gradually, when protagon separated in the form of microscopical 

 needles, differing a little in arrangement and form according to the 

 concentration of the solution. The substance thus obtained could be 

 recrystallized repeatedly. As a result of his analyses Liebreich 

 ascribed to protagon the formula C 116 H 241 1S"0 23 P. 



The following exhibits the percentage composition of protagon 

 according to this formula and the mean of all Liebreich's analyses : — 



Calculated for 

 Cn 6 H 24l N 4 22 P. Found. 



C 67-21 6674 



H 11-59 1174 



1ST 2-70 2-80 



P 1-50 1-23 



O 17-00 17-49 



* Oscar Liebreich, " Ueber die Chemische Beschaffenbeit der Grebirnsubstanz," 

 " Annalen der Cbemie und Pbarmacie," Bd. cxxxiv, s. 29-44. 



M 2 



