116 OPHIDIANS. il 
one of the poisons, ‘as far as possible to determine it with 
the means at our disposal. j 
In another place I have referred to a fact which has, pos- 
sibly, escaped the attention of observers hitherto; this is, 
that the venom which a reptile secretes in a state of nature, 
and that which it secretes in a state of captivity, possess dif- 
ferent degrees of virulence and develop somewhat different 
symptoms. My own observations and studies lead me to 
attribute this difference to the existence of an electro-magnetic 
element in all snake poisons, which is fully developed in a 
state of nature at the period in which the reptile is most con- 
stantly in motion, and which is at its minimum. when it is in 
a state of torpidity, or of little exercise, as in captivity. 
This will also explain why Dr. Weir Mitchell’s and others’ 
observations induce them to adopt the belief that the Crotalus 
does not emit a strong smell of musk; while, in a state of 
nature, this odor is so strong as to be exceedingly offensive. 
SNAKE POISONS, 
THEIR NATURE, ANALYSES OF THEM, AND SOME INTERESTING 
FACTS DERIVED FROM THE STUDY OF THEIR ACTION. 
Figure 1 represents the microscopical appearance of human 
blood: a a ais a front view of the globules, and 6 6 6 shows 
an edgewise view of them. The 
white background between the 
globules represents the plasma or 
liquid or vehicle through which 
the blood-globules are carried in 
the circulation. 
The plasma is composed of water, 
containing in solution a great num- 
ber of different substances. The 
presence of albumen, fibrin, various 
