LSS 



CHAPTER VIII. 



PHYSIOLOGY OF POISONING {continued). 



Action of Venoms on the Blood. 



On making an autopsy of an animal which has succumbed to 

 intoxication by snake-venom, we find that the blood in the heart 

 and large vessels is sometimes coagulated into a mass, sometimes 

 entirely fluid, and that, in certain cases, it is as black as prune- 

 juice, while in others it is of a fine transparent red colour. 



These differences in the effects of venom upon the blood are 

 due to the fact that the various venoms contain in variable pro- 

 portions, besides the neurotoxic substance which represents the 

 true venomous tox'ut, other substances which act, some upon the 

 plasmasia or fibrin-ferment, or upon the fibrin, others upon the 

 red corpuscles, others on the leucocytes, and others again on the 

 endothelium of the blood-vessels. 



A. — Effects of Venom on the Coagulation of the Blood. 



It was observed long ago by Fontana^ that after viper-bites 

 the blood remains fluid, and Brainard' on the contrary, pointed 

 out that, in the case of animals tbat succumb very rapidly after 

 having been bitten by a Crotahis, the blood was always found 

 coagulated into a mass, while, when a certain interval of time 

 had elapsed since the bite, it remained fluid. Weir MitchelF 



' Fontana, " On Poisons," translated by J. Skinner : London, 1787. 



- SiiiifJisuiitini lu'porfs, 1854. 



' SmitJisoniaii Coniribiiiioiii to Kiioiflcdyc, LS60. 



