THE PHYSIOLOGICAL ACTION OF SNAKE-VENOMS 175 
fighting fishes, that the natives of Annam rear in aquariums in 
order to witness their combats and make bets on them. The 
fishes died five hours after intramuscular inoculation with a dose 
which kills a pigeon in twenty minutes. 
Many invertebrates, such as leeches, crayfish, and gastropod 
molluscs (snails), are killed by inoculation with very small quantities 
of venom. 
C.—DETERMINATION OF THE LETHAL DOSES OF VENOM FOR 
DIFFERENT SPECIES OF ANIMALS. 
It is very difficult to specify, even within broad limits, the dose 
of venom necessary to kill a human being. The quantity of poison 
introduced by the bite of a venomous snake depends, as has already 
been stated, upon a large number of factors, and, very fortunately, 
this quantity is not always sufficient to cause death. Thus in 
India, that is to say in the region in which snakes are most 
numerous and most dangerous, the mean mortality seems scarcely 
to exceed 35 to 40 per cent., so far as it is possible to judge from 
official statistics. But, by experimenting upon animals, and com- 
mencing with known doses of venom, which has first been dried 
and then dissolved again in always the same quantity of physio- 
logical saline solution or sterile distilled water, we can determine 
exactly, for each kind of venom and for each species of animal, 
the minimum lethal dose per kilogramme of animal. 
The entire series of data collected by investigators who have 
devoted themselves to this study may be summed up as follows :— 
Minimal doses lethal in twenty-four hours for a guinea-pig 
weighing from 600 to 700 grammes :-— 
COLUBRID. 
Venom of Naja tripudians ... oe .… 0°0002 gramme 
i Bungarus ceruleus se non OH OOS, Fy 
Naja haje ... me Af 0:00 k. 
LE) 
