upon nitrous oxide gas, discovered by Priestley,
1774. In those experiments he fully
ascertained the exhilarating property of the gas,
and to some extent its power to render the
body insensible to pain; for on one occasion
having suffered much from the cutting of a
"wisdom tooth," and "whilst the inflammation
was at its greatest height," he says:— " I
inhaled at intervals the gas, and found after three
or four full inspirations, the pain left me, but
on ceasing to inspire it, I quickly recovered my
senses, and with those the acute pain of the
gum, not diminished in severity by the
experiment."

After this, which may be said to have been
a very good proof of its temporary anæsthetic
power, he does not appear to have continued
his research; although he did think it probable,
judging from his experience in the case of the
inflamed gum, that the nitrous oxide might be
used in slight surgical operations. From the
laboratory of this illustrious chemist the gas
found its way into every other throughout the
kingdom; and for many years its property of
producing a transient and very pleasant excitement
was exhibited at chemical lectures. It
was not, however, until the year 1844 that its
power to secure a complete insensibility to
pain was discovered and truly established by Dr.
Wells – an able American dentist with a faculty
for scientific observation – and in the following
manner: In the December of 1844 he attended,
in his native town, a lecture on chemistry,
delivered by Mr. Colton, and, amongst other
experiments, nitrous oxide gas was administered to
several of the gentlemen present. The effect of
the gas on different individuals was very
remarkably shown; some were greatly depressed
or sent off into a profound sleep, whilst others
were raised to the highest pitch of excitement,
and were cutting capers in a very ludicrous
manner. One of the caperers became quite
unmanageable, and hurt himself against the
benches of the room. When this gentleman
had regained his consciousness, he was asked
by Dr. Wells whether the wounds in his legs did
not hurt him, as the blood was flowing freely
from them. He replied that he was not aware
of having received any injury. As it appeared
that the gentleman had been, whilst under the
gas, either wholly or partially insensible to pain,
Dr. Wells determined, on the morrow, to inhale
the gas himself, and to have a tooth drawn by
way of experiment. Next day, therefore, he
procured the help of Mr. Colton, who administered
the gas to him. It took little more than
half a minute to bring him thoroughly under
its influence. The dentist then pulled out the
tooth, and Dr. Wells said, on recovering his
senses, " It did not pain me more than the prick
of a pin." After this discovery, many operations
were performed with the aid of the gas to
perfectly establish it, and with unvarying
success. During the next two years, not only was
it used exclusively by Dr. Wells in his practice
at Hartford, but it had spread to the principal
cities throughout the United States. The
method of preparing the gas was by heating the
nitrate of ammonia in a glass retort, great care
being taken to apply the flame gradually, so as
not to crack the retort, and also not to raise the
temperature above five hundred degrees
Fahrenheit, as otherwise the nitric oxide – a
powerful poison – would be given off along with
the nitrous oxide. The gas, as it came over,
was passed through water containing a solution
of the persulphate of iron, and was ultimately
secured in a large india-rubber bag, from which,
by means of a tube, the patient inhaled it.

From continual practice in the preparation
and administration of the gas, many improvements
were made by Dr. Wells, and in the latter
part of the year 1846, he undertook a journey
to Boston, to consult many of the eminent
surgeons of that city, as to the advisability of
trying it in surgical operations. Having had a
conference with Dr. Marcy, it was agreed, that,
in a surgical operation which the latter gentleman
had to perform, Dr. Wells should administer
the gas. The gas was accordingly
administered in presence of many of the most
distinguished medical gentlemen in Boston, and
the result answered every expectation of the
discoverer; the patient being some few minutes
under operation, and for the whole time
perfectly insensible to any pain. Shortly after this
another operation, amputation of the thigh,
was performed by Dr. Marcy, and the gas
administered again by Dr. Wells. The same
success attended it. As the gas gained standing
in the art of surgery, so its many disadvantages,
arising from the difficulty of preparing it,
became apparent, and many trials were made by
scientific men to discover a substance, which
would answer the same purpose, and be
more readily obtained. This substance, in the
form of sulphuric ether, was brought forward in
September, 1846, by Dr. Morton, a gentleman
living in Boston, of great standing in the
dental profession. The first case in which he
used it, was in the extraction of a firmly rooted
bicuspid tooth, the ether being placed on a
handkerchief, and given to the patient to inhale.
There was not much alteration in the pulse,
and no relaxation of the muscles. He
recovered in a minute and knew nothing of what
had been done to him. The success of this
operation, induced Dr. Morton to apply to
Dr. Warren, connected with the Massachusetts
General Hospital, in order to try the effect of
ether vapour in surgery. It was given in an
important operation performed by the latter
gentleman very soon after, and the ether having
been breathed during the whole time the patient
was throughout entirely insensible; yet the
recovery occupied but a few minutes.

The efficacy of sulphuric ether as an anæsthetic
was afterwards established by numberless operations,
which were performed without mishap
from its administration. Such a boon to mankind
was not long in arousing the medical world
of England and France, and within a few months
after the first use of sulphuric ether, at the
Massachusetts General Hospital, numerous