on which the action of the heart depends , &c. 
Chirac, Mr. Brodie, M. le Gallois, and others. This mode 
of destroying the sensibility does not influence the result of 
the experiment, and has the double advantage of preventing 
the animal’s sufferings, and his motions. Its greatest incon- 
venience is, that if the blow is very severe, considerable ves- 
sels are sometimes ruptured, and there is always some rupture 
of vessels, which of course tends to impair the vigour of the 
circulation. 
In the present experiment, the circulation was supported 
by artificial respiration. The spinal marrow was laid bare 
from the occiput to the beginning of the dorsal vertebras. 
The chest was then opened, and the heart- found beating 
regularly, and with considerable force. The spinal marrow’, 
as far as it had been laid bare, was now wholly removed, but 
without in the least affecting the action of the heart. After 
this, the artificial respiration being frequently discontinued, 
we repeatedly saw the action of the heart become languid, 
and increase on renewing it. The skull was then opened, 
and the whole of the brain removed, so that no part of the 
nervous system remained above the dorsal vertebras, but 
without any abatement of the action of the heart, which still 
continued to be more or less powerful, according as we dis- 
continued or renewed artificial respiration. This being for a 
considerable time discontinued, the ventricles ceased to beat 
about half an hour after the removal of the brain. On renew- 
ing the respiration, however, the action of the ventricles was 
restored. The respiration was again discontinuedand renewed, 
with the same effects. 
Exp. 2. A rabbit was made insensible by removing part of 
the skull, and applying opium to the brain. The spine was 
