156 



On LiebreicKs Protagon in the Brain. [June 19 r 



5. Once crystallized protagon from dog's brain. 



0-305 grm. gave 0- 7415 grm. of C0 2 and 0-289 grm. of H 2 0. Neither 

 P nor 1ST determined. 



6. Once crystallized protagon from dog's brain (same sample as 5). 

 0-25 grm. gave 0'6103 grm. of C0 2 and 0'249 grm. H 2 0. 



7. Four times crystallized protagon (prepared in 1877 by Mr. Lar- 

 muth) . 



0-214 g Tm . gave 0*5201 grm. C0 2 and 0"202 grm. H 2 0. 



8. Three times crystallized protagon (prepared by recrystallizing the 

 body which had furnished the samples used in Analyses 3 and 4). 



0-214 grm. gave 0*5203 grm. C0 2 and 0'2015 grm. of H 2 0. 



0-48 „ 9-7 cub. centims. of N (at 0° C. and 760 millims.). 



0-5164 „ 0-019 grm. of Mg 2 P 2 T . 



The results are shown in a tabular form below : — 



Protagon once Protagon twice Protagon twice Thrice re- Four times 

 recrystaflized recrystallized recrystallized crystallized recrys- 

 (dog). (ox). (ox). (ox). stallized 



t A ^ ( K ^ i A ^ (horse). 



No. 5. No. 6. No. 1. No. 2. No. 3. No. 4. No. 8. No. 7. 



C. ..66-3 66-6 66-46 66-58 66-34 66-35 66-30 66'26 



H. ..10-52 11-06 10-96 10-72 10-56 10-78 10-467 10-48 



N 2-3 2-6 2-40 .. 2-29 



P 1-094 1-107 1-032 1-081 1-027 



O. 



From the above numbers we have deduced for protagon the empirical 



Calculated. Mean found. 



formula C 160 H 308 ]S" 5 PO 



C 160 1920 66-45 66*39 



H 308 308 10-66 10-69 



N 5 70 2-42 2-39 



P 31 1 07 1-068 



35 560 19-40 



2889 100 -00 



A study of our results leaves no doubt of the definite and, within 

 certain limits, stable character of protagon. It is to be borne in mind 

 that in no case were the solutions containing protagon exposed to a 

 higher temperature than 45° C, as we have good reason to believe 

 that Liebreich was right in asserting that at higher temperatures 

 protagon undergoes decomposition. 



