A History of Science, vol 4 by Henry Smith Williams (the two towers ebook .TXT) 📕

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.

Meantime, 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