490 
DR. PHILIP ON THE POWERS ON WHICH 
However successfully such opinions might be combated by reasoning on the 
data we already possess, as direct experiment is the most simple as well as 
decisive way of determining the question, as reasoning on physiological subjects 
has so often deceived, and the experiments may here be made on the newly 
dead animal, and consequently without suffering of any kind, I have thought 
it better that the point should be determined in this way, especially as it is by 
experiments, which at first view seem to countenance the foregoing opinions, 
that their supporters attempt to establish them, with the effect, as it appears 
to me, of withdrawing the attention from the powers on which the circulation 
actually depends, and introducing considerable confusion respecting a question 
so immediately connected with the phenomena and treatment of disease. 
With a view, therefore, to submit the foregoing opinions to this test, the 
following experiments were made, in which Mr. Cutler was so good as to 
assist me. 
Exp. — A rabbit was killed in the usual way by a blow on the occiput, and the 
chest opened on both sides so as freely to admit the air. The lungs were then 
inflated eight or ten times in the minute by means of a pipe introduced into 
the trachea ; the circulation was found to be vigorous. On laying bare one of 
the femoral arteries, it was observed to pulsate strongly ; and on wounding it, 
the blood, of a florid colour, indicating that it had undergone the proper change 
in its circulation through the lungs, gushed out with great force ; and on intro- 
ducing the hand into the thorax, the heart was found to be alternately distended 
and contracted as in the healthy circulation. 
Exp. — All the vessels attached to the heart in the newly dead rabbit being 
divided, and the heart removed, it was allowed to empty itself. Its contrac- 
tions continued to recur, and in their intervals it assumed a perfectly flat shape, 
proving that the elasticity of the heart in this animal is so small that it cannot 
even maintain the least cavity after the blood is discharged. 
It appears from these experiments that the circulation was vigorous when 
none of the causes to which the motion of the blood in the veins have been 
ascribed existed. In the first experiment the chest being freely opened on 
both sides, so that the play of the lungs on inflating them could be seen, all 
effect on the heart either of the resilience of the lungs or the act of inspiration, 
was evidently prevented ; and in the second, it was proved that no sensible 
