Having entirely destroyed the sensibility in a
frog by the application of laudanum to the surface
of the animal, the brain and spinal marrow were
laid bare, and alcohol was applied successively,
first to the former, and then to the latter. But
the beat of the heart was precisely the same in
number, and apparently the same in force before
and after these applications of the spirit.
This experiment was repeated with the utmost
care, and before several competent witnesses,
with precisely the same result. The heart continued
to beat forty-two times in a minute for
a considerable time after the application of the
alcohol to the brain and spinal marrow, and with
the same apparent force.
Having applied laudanum to the skin of a
frog, the circulation in the web became slow,
as usual ; the respiration nearly ceased. The
brain was now laid bare, and alcohol was applied.
One particular arterial trunk in the web, with
its branches, and the adjacent capillaries, were
carefully noted. Not the slightest acceleration
of the. circulation of the web was detectible.
Indeed the circulation became slower rather than
quicker, and ultimately decidedly slower. The
spinal marrow was now laid bare, and alcohol
applied along its whole course. An artery and vein
crossing each other were carefully watched. Had
there been the slightest effect upon the circulation,
it must have been observed. But there was
none. In both instances the web had been
moistened just before the application of the
alcohol; and it was otherwise untouched. Nothing
could interfere with a change in the flow
of blood, had there been any cause tending to
produce such an effect. On exposing the heart,
it was found to beat slowly. The circulation was
seen in the larger pulmonary arteries. It had
ceased in the capillaries.
I believe there may be one difference between
Dr. Philip’s experiments and my own. I might
apply the laudanum more effectually ; yet I only
induced insensibility, the effect desired. The
moment this effect was obtained, I proceeded
with my experiment.
I have not thought it necessary to repeat the
experiment, because it must, at best, be a complicated
one, and therefore unsatisfactory. It
also appeared to me to be an improbable one.
It were singular, indeed, if spirit applied to the