Sir,
The facility of suspending
animation, by carbonic acid gas, and other means, without
permanent injury to the subject, having been long known, it
appears to me rather singular that no experiments have hitherto
been made with the object of ascertaining whether operations
could be successfully performed upon animals whilst in a torpid
state; and whether wounds inflicted upon them in such a state
would be found to heal with greater or less facility than similar
wounds inflicted on the same animals whilst in possession of all their
powers of feeling and suffering. Several circumstances led
me to suspect that wounds made on animals whilst in a torpid
state, would be found, in many cases, to heal most readily; and
the results of some experiments which I have made, lead me to
think that these conjectures are well founded, and to hope that
you will think the results sufficiently interesting to induce you
to do me the honor to lay them before the Royal Society.
The experiments were necessarily made upon living animals, but
they were confined to animals previously condemned to death; and
as their lives were preserved, and their suffering very slight,
(certainly not so great as they would have sustained if their
lives had been taken away by any of the ordinary methods of
killing such animals) I venture to hope that they, in the
aggregate, rather received benefit than injury. Subjects of
different species were employed, chiefly puppies of a few weeks
or months old, and the experiments were often repeated, but as
the results were all uniform, and as my chief object is to
attract the attention of other medical men to the subject, I
wish to do little more than state the general results.
Experiment 1st. Dogs of about
a month old were placed under a glass cover, surrounded by water,
so as to prevent the ingress of atmospheric air, where their
respiration in a short time ceased, and a part of one ear of each
was then taken off; there was no hemorrhage, and the wounds were
healed at the end of the third day, without any inflammation
having taken place, or the Animals having apparently suffered any
pain or inconvenience from the operation.
Experiment 2d. After the same
animals had fully recovered their powers of feeling, a similar
part of the other ear of each was taken off; a good deal of blood
now flowed from the wounds, and some degree of inflammation
followed, and the wounds did not heal till the fifth day.
Experiment 3d. An experiment
was made similar to No. 1, in every respect, except that the
suspension of animation was much more suddenly brought on by the
agency of sulphuric acid and carbonate of Lime. The results
in this case were not so satisfactory; some blood escaped from
the wounds, and a slight degree of inflammation followed, and the
wounds did not heal so rapidly as the first experiment.
Experiment 4th. Mice, having
been confined in a glass tube of a foot long, were rendered
insensible by carbonic acid gas slowly introduced in small
quantities, and one foot from each was taken off; no hemorrhage
took place upon the return of sensation, and the wounds appeared
quite healed on the third day, without the animals having
apparently suffered pain, when they were given their liberty.
Experiment 5th. An adult dog
was rendered insensible by means similar to the preceding, and
the muscles and blood-vessels of one of its legs were
divided. There was no hemorrhage from the smaller vessels;
a ligature which secured the main artery came away on the fourth
day, and the animal recovered without having at any period shewn any
material symptom of uneasiness. In this experiment
animation was suspended during seventeen minutes, allowing
respiration occasionally to intervene by means of inflating
instruments.
Experiment 6th. A dog was
rendered insensible by the means employed in experiment first,
and an incision was made through the muscles of the loin, through
which a ligature was passed, and made tight; no appearance
whatever of suffering occurred upon the return of animation, nor
till the following day, when inflammation came on with subsequent
suppuration. The ligature came away on the seventh day, and
on the twelfth the wound was healed.
As the recital of such experiments as those preceding must be
as little agreeable to you, as the repetition of them has been to
myself, I shall not give a detail of any others, but shall only
state the opinions which the aggregate results have led me to
entertain. I feel perfectly satisfied that any surgical
operation might be performed with quite as much safety upon a
subject in an insensible state, as in a sensible state, and that
a patient might be kept with perfect safety long enough in an
insensible state, for the performance of the most tedious
operation. My own experience has also satisfied me that in
very many cases the best effects would be produced by the
patient’s mind being relieved from the anticipation of
suffering, and his body from the actual suffering of a severe
operation; and I believe that there are few, if any Surgeons, who
could not operate more skillfully when they were conscious they
were not inflicting pain. There are also many cases in
which it would be important to prevent any considerable
hemorrhage, and in which the surgeon would feel the advantages of
a diminished flow of blood during an operation. I have
reason to believe that no injurious consequence would follow if
the necessity of the case should call for more than once
suspension of animation; for a young growing dog was several
times rendered insensible by carbonic acid gas, with intervals of
about twenty-four or forty-eight hours, without sustaining,
apparently, the slightest injury. Its appetite continued
perfectly good, and I ascertained, by weighing it, that it gained
weight rapidly. I am not, at present, aware of any source
of danger to a patient, from an operation performed during a
state of insensibility, which would not operate to the same
extent upon a patient in full possession of his powers of
suffering, particularly if he were rendered insensible by being
simply subjected to respire confined air. I used inflating
instruments in one experiment only, and therefore am not prepared
to say to what extent such may be used with advantage; but I
think it probable that those and the Galvanic fluid would operate
in restoring animation in some cases. I was prepared to
employ the Galvanic fluid if any case had occurred to render the
operation of any stimulant necessary, but all the subjects
recovered by being simply exposed to the open air; and I feel so
confident that animation in the human subject could be safely
suspended by proper means, carefully employed, that, (although I
could not conscientiously recommend a patient to risk his life
in the experiment,) I certainly should not hesitate a moment to
become the subject of it, if I were under the necessity of
suffering any long or severe operation,
I remain, Sir,
Your obedient Servant,
H. H. HICKMAN.
Shifnal, Aug. 14th, 1824.
FINIS.