PHYSIOLOGICAL ACTION OF VENOM OF BLACK SNAKE. 201 
the absolute amount of the gas contained in the blood was on the 
contrary, decreased. I therefore conclude that although the 
capacity of the blood to carry CO, may be, as one might expect 
from the analogy to other blood-corpuscle-destroyers, somewhat 
diminished, this is not a prominent feature of poisoning by the 
venom, and is entirely masked by the operation of other and more 
potent factors. The gradual increase in both the tension and 
amount of CO, in the venous and also in the arterial blood of 
the poisoned animal is to a large extent accounted for by the 
enfeeblement of the circulation and respiratory movements. 
Before this occurs it is not manifested, but afterwards it progresses 
hand in hand with the circulatory and respiratory depression. 
The exudation and hemorrhage into the lungs which is almost an 
invariable sequel to the injection of the poison, and whereby con- 
siderable areas are for the time being rendered useless, does no 
doubt also contribute in some degree to the same end. The 
existence of this factor is indicated in Experiment V., in which 
artificial respiration was ineffectual in reducing the high tension 
of CO, in the blood of the femoral artery to any great extent, 
and it is interesting to note that examination of the chest of this 
dog immediately after the experiment, discovered very extensive 
edema and hemorrhages throughout the greater part of the lungs. 
This pathological condition had evidently so curtailed the avail- 
able respiratory surface, that the larger portion of the blood 
passed through the lungs without an opportunity of coming in 
contact with the air in the alveoli. So that although the alveolar 
air was maintained of a high degree of purity by artificial inflation, 
the blood was not enabled to rid itself of its contained COp. 
a 
ie 
i 
4 
i 
. (f)— Influence of the venom on the germicidal action of serum. 
Weir Mitchell has drawn attention to the fact that the bodies 
" animals dead from rattle-snake poisoning putrefy with extreme 
rapidity, and that during life the local extravasations which are 
istic of this class of snake poisoning, as 4 general rule 
1 Loe. cit. 2 Loc. cit. 
