FEKMENTATION 219 



3.2-3.5 c.e. of -water containing rkin. The be- 

 ginning content of ricin should be 0.02 grn. ricin 

 for each cake ; 0.035 gm. is fatal in the course 

 of five or six days. Mix the biscuit powder and 

 ricin solution to a stiff dough, roll the dough into 

 rods, divide, them into equal lengths, and - dry 

 the portions quickly on a wire sieve. . Determine 

 the effect on white -mice of successively increas- 

 ing doses, as follows : 



DAY DOSE DAY DOSE 



1 0.002 gm. 9 0.02 



2 ... 10 0.03 



3 0.006 11 0.04 



4 . 0.008 12 0.05 



5 ... 13 0.06 



6 0.01 14 . . . 



7 . 0.0125 15 0.08 



8 0.015 16 0.01 



On the 17th day inject subcutaneously a fresh 

 mouse with the fatal dose 1 c.c. of a ^-dWo so ~ 

 lution per 20 gm. of mouse. At the same time 



even thus 0.18 gram will kill a full-grown man. The cause of 

 death is agglutination of red blood corpuscles, and hence 

 multiple thrombosis, especially of the abdominal vessels. 

 Clinically, violent diarrhoea and progressive exhaustion are ob- 

 served. The toxicity is greatly dependent on species. Guinea- 

 pigs are far more susceptible than white mice. With white 

 mice the fatal subcutaneous injection is 1 c.c. of a solution con- 

 taining ^injWtf ric ^ n P er 20 g rams f bo( ty weight. 



