428 



PROTAGON. 



[BOOK i. 



The resulting mass, which has a snow-white colour, is reduced to 

 powder, moistened with a little water, and digested for many hours 

 with alcohol heated to 45 C. From the filtered liquid, if this be 

 allowed to cool very gradually, the protagon separates in the form 

 of microscopic crystals, mostly arranged in rosettes, the appearance 

 and arrangement of which differ somewhat, as Liebreich very exactly 

 pointed out, according to the degree of concentration of the solution. 

 The once crystallized protagon thus obtained is collected on a filter, 

 washed with ether, and dried first of all in air and ultimately over 

 P 2 O 5 . It is then recrystallized as many times as required, the process 

 always commencing by pulverizing and thoroughly shaking with cold 

 ether. 



Results of With the object of proving the definite nature of 



ultimate protagon, the Author and Dr Blankenhorn subjected 



analyses of the body to repeated recrystallization, subjecting the 



product of the successive operations to ultimate ana- 



lysis. The following are the results of these analyses : 



C 

 H 

 N 

 P 

 O 



1-094 1-107 1-032 1-081 1*027 



From the above numbers we have deduced for protagon the 



empirical formula C 160 H 308 N 5 P0 35 . 



Calculated. 



1920 



308 

 70 

 31 



560 



2889 



10-66 

 2-42 

 1-07 



19-40 



Mean found. 



66-39 



10-69 



2-39 



1*068 



100-00 



From the results of these analyses it appears to the Author 

 that the existence of protagon as a definite chemical individual is 

 well-nigh proved. 



stability of It has been alleged by Diaconow and Hoppe-Seyler 



protagon. ^hat by prolonged treatment with ether and alcohol 



the whole of the phosphorus of protagon may be removed, and these 

 authors regard protagon as a mixture of a nitrogenous body (cerebrin) 

 with a phosphorized substance (lecithin). The most careful investi- 

 gation of the matter by the Author has led to entirely opposite con- 



