GENERAL PROPERTIES AND ACTIONS OF THE VENOM. 



83 



Crotalus, observed by Flexner and Noguchi,* was entirely or partially due to the 

 admixture of blood in the organs. These authors, as well as Phisalix,t estab- 

 lished the toxicity of the ova of venomous snakes, while we found the ova of 

 Heloderma to be devoid of any toxic effect. We may add that FraserJ de- 

 scribed an antivenomous action of the bile of serpents. 



INFLUENCE OF VENOM ON COAGULATION TIME OF THE BLOOD. 



The influence of the Heloderma venom on the coagulation time of the rab- 

 bit's blood was studied in various ways. The first method consisted in inject- 

 ing large quantities of venom intravenously and shortly before the death of the 

 animal, collecting the blood through a glass canula into a small test-tube. We 

 injected intravenously doses of venom of 20 to 30 mg., an amount causing the 

 death of the animal in periods varying from 5 to 10 minutes. The coagulation 

 time for the blood in these cases varied from 4 to 11.5 minutes, apparently 

 independent of the amount of venom injected or the interval between the 

 injections and the taking of the blood. In one case, a large quantity of blood 

 collected in a flask coagulated in 12 minutes. 



Since all the rabbits injected with venom died as a result of asphyxia 

 (death being due to respiratory failure), we considered it necessary to deter- 

 mine what influence asphyxia itself might have on the coagulation time of the 

 blood. We therefore compressed the trachea of a rabbit which was deeply 

 under the influence of ether and after 10.5 minutes of intermittent compres- 

 sion bled the animal. The blood collected in a small test-tube coagulated in 

 4 minutes; that collected in a small flask in 12 minutes. 



The results of these experiments lead to the conclusion that the venom of 

 the Heloderma has no distinct influence on the coagulation time of the blood. 



Influence of injection of venom on the coagulation of the rabbit's blood. 



aAfter last injection. 



The second method of testing the influence of venom on the coagulation 

 time of the blood was to allow blood to flow through a canula into a tube con- 

 taining various quantities of venom solution. In these experiments we used 

 0.5 c.c, 1 c.c, 2 c.c, and 3 c.c. of a 1 per cent solution of the dry venom to 2 

 c.c. of blood. In every case the fluid in the test-tubes was made up to 5 c.c. 

 with 0.85 per cent sodium-chloride solution. Furthermore, two control experi- 



*Jour. Path, and Bacteriol., vm, 1903. 

 {British Med. Journ., i, 1897. 



tCompt. Rend. Soc. Biol., 1905, lvii. 



