A History of Science, vol 4 by Henry Smith Williams (best novels to read for beginners txt) 📖
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local disease of the skin, due to a perfectly definite cause, and
the dire internal conditions formerly ascribed to it have really
no causal connection with it whatever. This definite cause, as
every one nowadays knows, is nothing more or less than a
microscopic insect which has found lodgment on the skin, and has
burrowed and made itself at home there. Kill that insect and the
disease is no more; hence it has come to be an axiom with the
modern physician that the itch is one of the three or four
diseases that he positively is able to cure, and that very
speedily. But it was far otherwise with the physicians of the
first third of our century, because to them the cause of the
disease was an absolute mystery.
It is true that here and there a physician had claimed to find an
insect lodged in the skin of a sufferer from itch, and two or
three times the claim had been made that this was the cause of
the malady, but such views were quite ignored by the general
profession, and in 1833 it was stated in an authoritative medical
treatise that the “cause of gale is absolutely unknown.” But
even at this time, as it curiously happened, there were certain
ignorant laymen who had attained to a bit of medical knowledge
that was withheld from the inner circles of the profession. As
the peasantry of England before Jenner had known of the curative
value of cow-pox over smallpox, so the peasant women of Poland
had learned that the annoying skin disease from which they
suffered was caused by an almost invisible insect, and,
furthermore, had acquired the trick of dislodging the pestiferous
little creature with the point of a needle. From them a youth of
the country, F. Renucci by name, learned the open secret. He
conveyed it to Paris when he went there to study medicine, and in
1834 demonstrated it to his master Alibert. This physician, at
first sceptical, soon was convinced, and gave out the discovery
to the medical world with an authority that led to early
acceptance.
Now the importance of all this, in the present connection, is not
at all that it gave the clew to the method of cure of a single
disease. What makes the discovery epochal is the fact that it
dropped a brand-new idea into the medical ranks—an idea
destined, in the long-run, to prove itself a veritable bomb—the
idea, namely, that a minute and quite unsuspected animal parasite
may be the cause of a well-known, widely prevalent, and important
human disease. Of course the full force of this idea could only
be appreciated in the light of later knowledge; but even at the
time of its coming it sufficed to give a great impetus to that
new medical knowledge, based on microscopical studies, which had
but recently been made accessible by the inventions of the
lens-makers. The new knowledge clarified one very turbid medical
pool and pointed the way to the clarification of many others.
Almost at the same time that the Polish medical student was
demonstrating the itch mite in Paris, it chanced, curiously
enough, that another medical student, this time an Englishman,
made an analogous discovery of perhaps even greater importance.
Indeed, this English discovery in its initial stages slightly
antedated the other, for it was in 1833 that the student in
question, James Paget, interne in St. Bartholomew’s Hospital,
London, while dissecting the muscular tissues of a human subject,
found little specks of extraneous matter, which, when taken to
the professor of comparative anatomy, Richard Owen, were
ascertained, with the aid of the microscope, to be the cocoon of
a minute and hitherto unknown insect. Owen named the insect
Trichina spiralis. After the discovery was published it
transpired that similar specks had been observed by several
earlier investigators, but no one had previously suspected or, at
any rate, demonstrated their nature. Nor was the full story of
the trichina made out for a long time after Owen’s discovery. It
was not till 1847 that the American anatomist Dr. Joseph Leidy
found the cysts of trichina in the tissues of pork; and another
decade or so elapsed after that before German workers, chief
among whom were Leuckart, Virchow, and Zenker, proved that the
parasite gets into the human system through ingestion of infected
pork, and that it causes a definite set of symptoms of disease
which hitherto had been mistaken for rheumatism, typhoid fever,
and other maladies. Then the medical world was agog for a time
over the subject of trichinosis; government inspection of pork
was established in some parts of Germany; American pork was
excluded altogether from France; and the whole subject thus came
prominently to public attention. But important as the trichina
parasite proved on its own account in the end, its greatest
importance, after all, was in the share it played in directing
attention at the time of its discovery in 1833 to the subject of
microscopic parasites in general.
The decade that followed that discovery was a time of great
activity in the study of microscopic organisms and microscopic
tissues, and such men as Ehrenberg and Henle and Bory
Saint-Vincent and Kolliker and Rokitansky and Remak and Dujardin
were widening the bounds of knowledge of this new subject with
details that cannot be more than referred to here. But the
crowning achievement of the period in this direction was the
discovery made by the German, J. L. Schoenlein, in 1839, that a
very common and most distressing disease of the scalp, known as
favus, is really due to the presence and growth on the scalp of a
vegetable organism of microscopic size. Thus it was made clear
that not merely animal but also vegetable organisms of obscure,
microscopic species have causal relations to the diseases with
which mankind is afflicted. This knowledge of the parasites was
another long step in the direction of scientific medical
knowledge; but the heights to which this knowledge led were not
to be scaled, or even recognized, until another generation of
workers had entered the field.
PAINLESS SURGERYMeantime, in quite another field of medicine, events were
developing which led presently to a revelation of greater
immediate importance to humanity than any other discovery that
had come in the century, perhaps in any field of science
whatever. This was the discovery of the pain-dispelling power of
the vapor of sulphuric ether inhaled by a patient undergoing a
surgical operation. This discovery came solely out of America,
and it stands curiously isolated, since apparently no minds in
any other country were trending towards it even vaguely. Davy,
in England, had indeed originated the method of medication by
inhalation, and earned out some most interesting experiments
fifty years earlier, and it was doubtless his experiments with
nitrous oxide gas that gave the clew to one of the American
investigators; but this was the sole contribution of preceding
generations to the subject, and since the beginning of the
century, when Davy turned his attention to other matters, no one
had made the slightest advance along the same line until an
American dentist renewed the investigation.
In view of the sequel, Davy’s experiments merit full attention.
Here is his own account of them, as written in 1799:
“Immediately after a journey of one hundred and twenty-six miles,
in which I had no sleep the preceding night, being much
exhausted, I respired seven quarts of nitrous oxide gas for near
three minutes. It produced the usual pleasurable effects and
slight muscular motion. I continued exhilarated for some minutes
afterwards, but in half an hour found myself neither more nor
less exhausted than before the experiment. I had a great
propensity to sleep.
“To ascertain with certainty whether the more extensive action of
nitrous oxide compatible with life was capable of producing
debility, I resolved to breathe the gas for such a time, and in
such quantities, as to produce excitement equal in duration and
superior in intensity to that occasioned by high intoxication
from opium or alcohol.
“To habituate myself to the excitement, and to carry it on
gradually, on December 26th I was enclosed in an air-tight
breathing-box, of the capacity of about nine and one-half cubic
feet, in the presence of Dr. Kinglake. After I had taken a
situation in which I could by means of a curved thermometer
inserted under the arm, and a stop-watch, ascertain the
alterations in my pulse and animal heat, twenty quarts of nitrous
oxide were thrown into the box.
“For three minutes I experienced no alteration in my sensations,
though immediately after the introduction of the nitrous oxide
the smell and taste of it were very evident. In four minutes I
began to feel a slight glow in the cheeks and a generally
diffused warmth over the chest, though the temperature of the box
was not quite 50 degrees… . In twenty-five minutes the animal
heat was 100 degrees, pulse 124. In thirty minutes twenty quarts
more of gas were introduced.
“My sensations were now pleasant; I had a generally diffused
warmth without the slightest moisture of the skin, a sense of
exhilaration similar to that produced by a small dose of wine,
and a disposition to muscular motion and to merriment.
“In three-quarters of an hour the pulse was 104 and the animal
heat not 99.5 degrees, the temperature of the chamber 64 degrees.
The pleasurable feelings continued to increase, the pulse became
fuller and slower, till in about an hour it was 88, when the
animal heat was 99 degrees. Twenty quarts more of air were
admitted. I had now a great disposition to laugh, luminous points
seemed frequently to pass before my eyes, my hearing was
certainly more acute, and I felt a pleasant lightness and power
of exertion in my muscles. In a short time the symptoms became
stationary; breathing was rather oppressed, and on account of the
great desire for action rest was painful.
“I now came out of the box, having been in precisely an hour and
a quarter. The moment after I began to respire twenty quarts of
unmingled nitrous oxide. A thrilling extending from the chest to
the extremities was almost immediately produced. I felt a sense
of tangible extension highly pleasurable in every limb; my
visible impressions were dazzling and apparently magnified, I
heard distinctly every sound in the room, and was perfectly aware
of my situation. By degrees, as the pleasurable sensations
increased, I lost all connection with external things; trains of
vivid visible images rapidly passed through my mind and were
connected with words in such a manner as to produce perceptions
perfectly novel.
“I existed in a world of newly connected and newly modified
ideas. I theorized; I imagined that I made discoveries. When I
was awakened from this semi-delirious trance by Dr. Kinglake, who
took the bag from my mouth, indignation and pride were the first
feelings produced by the sight of persons about me. My emotions
were enthusiastic and sublime; and for a minute I walked about
the room perfectly regardless of what was said to me. As I
recovered my former state of mind, I felt an inclination to
communicate the discoveries I had made during the experiment. I
endeavored to recall the ideas—they were feeble and indistinct;
one collection of terms, however, presented itself, and, with
most intense belief and prophetic manner, I exclaimed to Dr.
Kinglake, ‘Nothing exists but thoughts!—the universe is composed
of impressions, ideas, pleasures, and pains.’ “[3]
From this account we see that Davy has anaesthetized himself to a
point where consciousness of surroundings was lost, but not past
the stage of exhilaration. Had Dr. Kinglake allowed the
inhaling-bag to remain in Davy’s mouth for a few moments longer
complete insensibility would have followed. As it was, Davy
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