7s Dr. Philip’s experiments to ascertain the principle 
it had been continued for about half a minute, the blood, which 
continued to flow copiously from the artery, became of a 
highly florid colour. The other femoral artery was then 
opened, from which florid blood also flowed freely. When 
about an ounce of blood had flowed from the two vessels, the 
inflation of the lungs was discontinued, and the blood again 
flowed of a dark colour. On renewing the inflation of the 
lungs, the blood, in less than half a minute, again became of 
a florid colour. It continued to flow from the femoral arte- 
ries altogether for seven minutes. Three minutes after the 
blood had ceased to flow from them, the artificial respiration 
being continued, one of the carotid arteries was opened, from 
which a florid blood flowed in a free stream, to the amount of 
a dram and a half. The flow from the carotid artery ceased 
in eleven minutes after the femoral artery had been opened. 
Most of the blood was now of course evacuated. A good 
deal had been lost in opening the spine, which always hap- 
pens. The left auricle and ventricle were found nearly empty. 
The blood which remained in them was florid. The right 
auricle and ventricle were full of dark blood. 
Exp. g. From various trials, we found that in such expe- 
riments the circulation ceases quite as soon without, as with 
the destruction of the spinal marrow. Loss of blood seems 
to be the chief cause which destroys it. When the animal 
was operated upon, without being rendered insensible, pain 
also contributed to this effect. We frequently, after laying 
open the skull and spine, found the circulation lost before 
either the brain or spinal marrow had been disturbed. In the 
younger rabbit, it was lost sooner than in the older. The for- 
mer seemed to die sooner from any injury, except the inter- 
