THE QUANTITY OF VENOM INJECTED. 313 
no outward symptoms of poisoning. There was no swelling, 
and the animal fed as usual, and was as lively as ever. 
On the fourth day I extracted three drops of venom from 
one of the Puff Adders which had bitten the Jackal. This was 
mixed with a_ teaspoonful of pure water and injected into the 
muscles of the other thigh of the Jackal, by means of a serum 
syringe. One hour later the Jackal was dead. A post-mortem 
showed the limb swollen twice its normal size. The flesh 
of the whole limb from the toes up to the junction with the 
body, was saturated with blood which had oozed through 
the walls of the blood vessels into the surrounding tissues. 
The muscles of the whole body were more or less stained with 
extravasated blood, and the heart was also affected. 
The limb was then examined which had been bitten by the 
two Puff Adders. All about the sites of the bites the muscles 
were much discoloured with blood, which had oozed into the 
tissues. This was traced up the leg and half-way along the side. 
It was apparent that venom had been injected when the snakes 
inflicted their bites, but not in sufficient quantity to cause 
swelling or other noticeable symptoms. Now, if I had relied 
upon this case as a demonstration of the efficacy of some 
favourite “‘ cure,” I should have been altogether wrong in my 
conclusions. 
THE QUANTITY OF VENOM INJECTED. 
When a venomous snake inflicts a full bite he drives his fangs 
into the flesh and retains his hold for a moment or two, at the 
same time gripping hard. Now, in most cases of snake bite 
with human beings and the larger animals, the victim generally 
sees the snake lunge and springs away or shakes off the reptile 
the moment it bites. If he does not happen to see it strike he will, 
on the instant, leap, kick, or otherwise disengage the snake’s 
fangs before it is able to grip the flesh and press in a full charge 
of venom. I have frequently made snakes bite animals with 
the object of demonstrating that if a snake is allowed to get a 
full grip and hold on for a second or two, the amount of venom 
injected is double and often ten or more times greater than if 
the reptile struck and instantly disengaged its fangs. This is 
ascertained by observing the length of time the animals survived. 
