relation between the nervous and sanguiferous systems. 43 9 
warm blood. Both Fontana and Dr. Monro observe, that 
in their experiments they found the system of both obeying 
the same laws. The experiments I have had occasion to lay 
before the Society, tend to confirm this observation ; and I 
may say the same of all the experiments I have made on both 
sets of animals. There are certain circumstances in which 
they evidently differ, in all others they seem to agree. The 
following experiments ought not to be unnecessarily repeated, 
and as there is no part of the warm blooded animal on which 
they could be satisfactorily made except the mesentery, they 
would be attended with much greater suffering in this, than 
in the cold blooded animal. Some of them, from the warm 
blooded animal being less tenacious of life, could not be per- 
formed on it. 
Exp. 11. A strong ligature was thrown round the neck of 
a frog, and the head cut off without any loss of blood ; much 
loss of blood immediately destroys the circulation in the ex- 
tremities. The spinal marrow was then destroyed by a wire. 
On bringing the web of one of the hind legs before the 
microscope, the circulation in it was found to be vigorous, 
and continued so for many minutes. This experiment was 
repeated with the same result. 
It appears from this experiment, that the blood vessels re- 
tain their power after the nervous system is wholly destroyed. 
In order to ascertain, how far the vessels can be stimulated 
through the nervous system, independently of any action of 
this system on the heart, it is necessary in the first place to 
determine, whether the vessels can support the motion of the 
blood independently of the heart. 
Exp. 12. A ligature was thrown round all the vessels 
