428 Drs. C. J. Martin and T. Cherry. 



II. Experiments to confirm Brodie's* statement that the Antitoxin of 



Diphtheria does not pass through a Gelatin Filter. 



0*5 c.c. of Pasteur Institute antitoxin was mixed with 1 o.e. of toxin 

 No. 1 (=8 fatal doses per kilo.), and injected into a guinea-pig 

 weighing 260 grams. 



The animal remained well and gained 26 grams during the 

 four days it was kept under observation. The same sample of anti- 

 toxin was passed through the filter. Of the filtrate 0*6 c.c. was 

 mixed with 0'6 c.c. of the same toxin and injected into a guinea-pig 

 weighing 163 grams. The animal died in 22 hours. 



III. Experiments to show that when Diphtheria Toxin is mixed with 

 Diphtheria Antitoxin in sufficient quantity, and allowed to remain in 

 contact for a sufficient time, the filtrate which has passed through 

 a Gelatin Filler is free from Toxin. 



60 c.c. of toxin No. 1 (containing approximately 500 lethal doses 

 per kilogram) was mixed with 2'5 c.c. of Behring's antitoxin 

 <(= 600 units). The two were well mixed and allowed to stand at 

 30 C. for two hours before filtration. 



The filtrate was injected subcutaneously into guinea-pigs as 

 under : 



The animals were absolutely unaffected. They never failed in 

 appetite, nor was there any local oedema. 



B. EXPERIMENTS WITH SNAKE VENOM. 



IY. Experiments to determine the Minimal Fatal Dose of the Poison 



used. 



The venom employed was that of Hoplocephalus curtus. This had 

 been procured free from admixture with saliva by making the reptiles 

 bite into a watch-glass covered with thin rubber sheeting. The 

 liquid poison was rapidly dried at ordinary temperatures (15 20 C.) 

 over calcium chloride, powdered, and stored in a stoppered bottle. 



* Loc. cit. 



