30 THE VENOMS OF CERTAIN THANATOPHIDE^E. 



same holds good, but our experiments with Cobra venom show that a larger pro- 

 portional quantity is needed to destroy its power. 



Experiment. — Dissolved 0.015 gram Cobra venom in 0.5 c. c. distilled water, 

 then added an equal amount of potassic hydrate. 



4:05. Injected into the breast muscles of a pigeon. 



4:22. Unable to stand. 



4:32. Convulsions. 



4:37. Dead. 



This experiment was repeated with a similar result. 



A larger proportion of the potassic hydrate was used in the following observa- 

 tions : — 



Experiment. — The same as above, using 0.03 gram (double the amount) of 

 potassic hydrate. 



4:51. Injected into the breast of a pigeon. 

 No effects. 



Repeated this experiment with a similar result. 



In one instance, however, we found that 0.06 gram potassic hydrate did not 

 effectually counteract the poisonous activity of 0.015 gram dried Cobra. 



It has been suggested that the non-poisonous action of venom treated with 

 potassic hydrate and injected hypodermically, as in the above experiments, depends 

 upon an effect of the potassic salt on the tissues, causing a considerable delay 

 in the absorption of the poison, and this suggestion seems strengthened by the 

 result in a rabbit of an intravenous injection of 0.015 gram Crotalus venom 

 with 0.06 gram potassic hydrate in 1 c. c. distilled water. The animal became 

 very sick soon after the injection, which was given in the evening, and remained in 

 this condition at the end of an hour, when the observation ceased. The following 

 morning it was found dead, with post-mortem appearances of the effects of venom. 

 Also, in another animal, which was given intravenously 0.015 gram of venom with 

 a similar amount of potassic hydrate, death occurred as promptly as with pure 

 venom; in fact rather earlier. 



In another set of experiments on pigeons, we carefully neutralized the potassic 

 hydrate before injecting. We used in all of this series sulphuric acid as the 

 neutralizing principle, so that a harmless potassic sulphate was formed. The 

 results of this group of experiments also go to show that the potassic hydrate 

 prevents the absorption of the venom. 



Experiment. — Dissolved 0.015 gram dried venom of the Crotalus adamanteus 

 in 1 c. c. distilled water and added 0.015 gram potassic hydrate, then carefully 

 neutralized with acetic acid. 



This was injected into the breast of a pigeon, causing death in sixteen minutes. 



Experiment. — Dissolved 0.03 gram dried Crotalus adamanteus venom in 1 c. c. 

 distilled water and added 0.015 gram potassic hydrate, and then neutralized as above. 



4:19. Injected as above. 



4:55. Weak ; breathing rapid. 



6:20. Much weaker. 



Following morning. Dead. Decided local effect; blood fluid and dark. 



