muscular power to the arteries, and 2. by
ascribing a power to the capillaries of which
there is hitherto no proof;
5. Hunter seems first to have had clear views
of the muscular power of the arteries;
6. The proof of the irritability of the arteries
was still deficient until the discovery of an artery
which actually pulsates independently of the heart,
in some of the batrachia;
7. The influence of atmospheric pressure in
aiding the circulation in the veins, was clearly
suggested by Huxham, but actually proved by
experiment, by Dr. Barry ;
8. The opinion of Haller, in regard to the
irritability of the muscular fibre, is still, under
certain limitations, the true one;
9. The voluntary and involuntary muscles alike
retain their irritability for a time, after their
communication with the nervous system is cut
off ; both gradually lose it ;
10. The experiment of removing the brain
and spinal marrow, and of watching the effect
on the heart and capillary circulation, belongs
to a former day, and especially to Whytt and
Spallanzani;
11. The repetitions of this experiment by Le-
gallois, Dr. Philip, M. Flourens, and M. Brachet
are, in my opinion, less satisfactory than the
original experiments of Whytt and Spallanzani,
having occupied less time, and consequently
afforded less scope for observation ;
12. Nothing appears to have been added to
the original experiments, except the important
fact of the difference between removing the brain
and spinal marrow at once, and by portions at
distant intervals, a fact discovered by Legallois;
13. On the other hand, some of the opinions
of the more modern experimenters appear to
me to be unfounded ; for example—
14. (1.) The opinion of Legallois, that to destroy
a portion of the spinal marrow annihilates the
circulation in the parts which derive their nerves
from it ; and
15. (2.) That of M. Flourens, that the circulation
depends upon that part of the medulla
on which respiration depends.