182 MICROBES AND TOXINS 



digests albumins but without reaching the peptone stage. The 

 digestive properties are destroyed by heating to 70° C. 



Pancreatic juice, as is well known, when perfectly pure 

 cannot alone, digest albumin ; it has to be " activated " by a 

 "kinase " ferment, secreted either by the intestinal mucosa or 

 by the leucocytes. Now snake-venoms can take the place of 

 this kinase and activate a pure inactive pancreatic juice. This 

 is all the more curious since the pancreatic juice when 

 activated digests and destroys venoms, which, as a rule, have 

 in consequence no action when taken by the mouth. The 

 venom secretion is thus for the snake itself a normal 

 physiological secretion of great use in the digestion of the 

 huge meals for which snakes are famous. There is further 

 nothing surprising in the fact that non-venomous snakes, i.e., 

 those not provided with poison-fangs, still possess glands 

 capable of secreting venom ; it is simply used in the digestion 

 of their food. 



Venoms thus, like toxins, resemble ferments — with the same 

 reservations. They are very closely allied to toxins. Their 

 action, like that of toxins, is not simple ; just as in tetanus 

 toxin several different substances or functions can be dis- 

 tinguished, a nerve-cell poison and a poison of the red blood 

 corpuscles, so several physiological activities can be dis- 

 tinguished in the same venom. But venoms act without any 

 incubation period, or at any rate with a very short one. It is 

 only the time elapsing between inoculation and death that 

 varies with the dose, and that within rather narrow limits. 



Like the toxins, the venoms are destroyed at relatively low 

 temperatures (resistance up to 100° to 110° C. does not interfere 

 with the analogy). They act in minute dose and deteriorate 

 or are destroyed by light, by photodynamic substances, by 

 iodine perchloride, and alkaline hypochlorites. 



Finally, and most important, the venoms give rise to 

 antivenoms, as toxins do to antitoxins. It is practically only with 

 the help of the antivenoms indeed that the specificity of the 

 venoms can be definitely demonstrated. 



Venom Haemolysis.— The venoms are hsemolytic 



