CHAPTER VIII. 
EFFECTS OF VARIOUS PHYSICAL AND CHEMICAL AGENTS 
UPON SNAKE VENOM. 
This includes the effects of various physical and chemical agents on venom 
en masse as well as on certain active constituents of venom obtained by 
chemical processes. As the constituents of different venoms differ both in 
quantity and quality, the effects of various agents upon them differ accord- 
ingly. 
EFFECTS OF PHYSICAL AGENTS. 
Effect of desiccation: When allowed to dry at ordinary temperature, all 
venoms do not suffer a loss in their toxicity. In some viperine or crotaline 
venoms a slight reduction in their local activity has been observed after 
desiccation, but never to a great extent. 
Effect of preservation: The active principles of snake venom are very 
stable when kept in a dry state or in a mixture with equal quantity of gly- 
cerin. So far as records go, dried crotalus venom after 23 years was just as 
active as when it was freshly collected (Mitchell), and dried cobra venom 
preserved for 15 years (Christison) or 16 years (Vollmer) did not show any 
sign of deterioration of its original strength. On the other hand, when in 
saline or watery solution, the venom gradually loses its activity. This fact is 
especially marked with cobra venom, and at body temperature. 
Effect of moist heat: ‘The venom of Elapine (Naja, Elaps, Bungarus, 
Hoplocephalus, Pseudechis) can be exposed to the temperature of 100° C. for 
a brief period, without reducing its activity to any marked degree. Fayrer 
and Brunton mention that a 30-minutes heating of cobra venom at 102° C. 
destroys the latter. Wall states that 106° C. maintained for 30 minutes is 
sufficient to destroy cobra venom. Kanthack saw cobra venom become 
harmless after an hour’s boiling at 100° C. Mitchell and Reichert found 
that the prolonged boiling produced gradual coagulation of the venom- 
peptone and rendered it inert. 
The venom of Hydrophiinz withstands even a brief boiling with im- 
punity. 120° C. always suffices to cause total inactivation or destruction 
of all venoms. 
The venoms of Viperinz and Crotaline are much more sensitive to the 
destructive action of heating. ‘The temperature which produces coagulation 
of the proteins of these venoms destroys the greater part of their poisonous 
activity. The temperature of 72° to 75° C. removes most of the toxicity, 
while almost complete inactivation is brought about at 80° to 85° C. But 
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