PHYSIOLOGICAL ACTION OF VENOM OF BLACK SNAKE. 233 
artificial inflation of the lungs. The effect upon the blood 
pressure without artificial respiration can, however, be seen on 
reference to the experiments at the end of the section on the effects 
of the venom upon the respiration. In the detailed account of 
those experiments, the pressure in the carotid artery at intervals 
during the course of the experiment, is enumerated, together with 
the rate and amplitude of the respiratory movements. On com- 
paring the experiments with and without artificial respiration, it 
will be seen that life is only prolonged to a very short extent by 
maintaining the respiratory efficiency of the animal by mechanical 
inflation. 
Tf death from asphyxia be prevented by such means, the animal 
succumbs within a few minutes from heart failure. Experiments 
26, 27 and 28, in which the artificial inflation was suspended for 
a few seconds at intervals in order to ascertain the extent of the 
action of the poison on the respiratory mechanism, show that 
the heart ceased to beat within five minutes from the time when 
natural respiration had completely ceased. 
The animals upon which these experiments were performed 
Were rabbits. They were anesthetised with ether, and the carotid 
artery connected with a mercury manometer. The trachea was 
connected with a Marey’s tambour and the artificial respiration 
pump. The air was warmed by being passed through coils of 
lead Pipe immersed in hot water before being pumped into the 
lungs. The arrangement of these connections was such as to 
admit of changing from artificial to.natural respiration or vice 
versa by turning a tap, and without interfering with the registering 
tambour. A tracing of the normal blood pressure was first obtained, 
= then the poison dissolved in 1 cc. of normal salt solution, 
injected, Further tracings were taken at intervals of fifteen 
ae or less, during the course of the experiment. The poison 
Was injected into the peritoneal cavity in two experiments and in 
the others under the skin of the abdomen. The result of all the 
