which it exists in laudanum, I was equally surprised
to find the simultaneous occurrence of an
obliterated circulation and of a complete tetanus.
In the second place, on applying alcohol to the
surface of the brain and spinal marrow, after
inducing insensibility by laudanum, I could discover
no acceleration whatever, either in the beat
of the heart or in the circulation of the blood in
the web. I shall briefly detail my experiments.
I applied laudanum over the back part of a frog
carefully avoiding its contact with the web. In less
than half an hour the respiration and all sensibility
had ceased, and the capillary circulation became, at
the same time, more distinctly pulsatory in the
arteries, and more and more slow and feeble in the
capillary vessels and veins. This effect became
gradually more marked, and in two hours the circulation
had ceased almost entirely in all the three
sets of vessels. I now washed off the laudanum
and placed the frog in water. The circulation at
first gradually, afterwards more speedily, returned,
and became very vivid and vigorous, even before
there was the slightest return of the respiration *
the respiration and sensibility at length also
returned completely. The laudanum was reapplied
and again removed with precisely the same effects.
The insensibility was so perfect that the eyes were
not retracted on being touched. The recovery
was prompt and complete.
I repeated the experiment with diluted alcohol,
with similar effects.
The experiment was now made with a mixture
of opium and water. It was long before it produced
any effect. At length, however, the circulation
in the web ceased, and the animal became
affected with complete tetanus.
The same effect was produced more speedily on
inducing the animal to swallow a few drops of the
opiate solution.
These effects of laudanum are precisely what
were observed by Dr. Alston -of Edinburgh more
than a century ago. Dr. Alston relates his experiments
in the following characteristic manner :
“ In the physick garden at Holyroodhouse (where
all the Experiments on Frogs were made) I one
evening put a big strong Paddock into a Pot of
Water, wherein a small Quantity of Opium, was
dissolved ; it soon appear’d to be uneasy, by
making strong Efforts to get out of it, but in a
short time it flag’d or grew dull, making very little
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