The Antagonism between Toxins and Antitoxins. 431 



VII. Experiments to determine the influence of variations in the time 

 during which venom, and antivenomous serum, operated upon one 

 another. 



In this series of experiments, the same samples of venom and 

 serum were employed as before. The relative proportions of the 

 two were kept constant. The venom solution and serum were 

 mixed together in the proportion of O'OOOl gram of venom to 1 c.c. 

 of the serum and well stirred. After they had remained in contact 

 at the temperature of the laboratory (21 C.) for times varying 

 from 2 to 30 minutes, portions were pipetted off, and rapidly 

 raised to 68 C., at which temperature they were kept for 10 minutes. 

 The portions were then rapidly cooled, and injected subcutaneously 

 in quantities proportionate to the body weights of the animals. 

 Amounts of venom and of serum equivalent to O'OOOl gram and 1 c.c. 

 respectively per kilogram of body weight were injected in each case, 

 except the control, when this quantity of venom was employed. 



* In Experiment No. IV no serum was mixed with the venom, but the venom 

 solution was heated alone to 68 C. for 10 minutes to show that this treatment has 

 no influence upon it. 



