20 
Transactions Texas Academy of Science. 
mental condition; with the nature of the bite — whether both fangs 
or only one has been introduced, whether they have penetrated 
deeply or only scratched the surface ; and with other circumstances 
related to the serpent, such as whether it had recently bitten an 
animal or not, and thus parted with a portion or retained the whole 
of the venom stored in the poison glands. * * * The quantity 
required to produce death being very exactly related to each pound 
or kilogramme of weight.” 29 Fraser found the minimum-lethal 
dose per kilogramme to be : “For the guinea-pig (of dried venom), 
0.00018 gm. ; for the frog, 0.0002 gm. ; for the rabbit, 0.000245 
gm. ; for the white rat, 0.00025 gm. ; for the oat, somewhat less 
than 0.005 gm. ; and for the grass snake (Tropedonotus natrix), 
the relatively large dose of 0.03 gm.” 30 
It is significant that the toxicity of cobra venom is not the same 
for all animals. Furthermore, it is exceedingly interesting to find 
that the experiments carried out by Fraser, in vitro and in the 
animal organism, leave practically no room for doubt that the 
poisonous action of snake venom and the antagonistic action of 
antivenin are both chemical. In the unprotected animal snake 
venom injected beneath the skin or into the blood stream gives 
immediate evidence of reactions of an endothermic character; but 
when in the same manner it is introduced into protected animals 
evidence of exothermic reactions is elicited. When introduced into 
the stomach of an animal snake venom not only fails to induce 
symptoms of poisoning, but exhibits a neutralizing action upon 
inoculated venom, and in the uninoculated animal confers immu- 
nity against snake venom. Moreover, the ratio between venom and 
antivenin is quantitatively brought out in the experiments of 
Fraser. All this can be shown to be in conformity with well known 
Chemical laws. 
Numerous examples which illustrate the chemical nature of the 
action of toxalbumins might be drawn from various intra- and 
intercellular protoplasmic bodies found in the vegetable and animal 
kingdom, but time will not permit their multiplication here. A 
bountiful supply is to be found in recent biochemical and medical 
literature, and interested persons are referred to that source. 
The specific phenomena of these poisons as exhibited in the 
human body when toxic quantities are taken will be found in 
nearly every text-book of modern medicine, so there is no need to 
repeat them here. 
What has been said of the chemistry of fermentation is equally 
applicable here. Specific illustrations and their enlargement just 
now would take us beyond the limits of this address; for that 
