In experimental science, two methods of progress are observed; first,
in actual practice certain methods are adopted because they are found
to be the most advantageous and useful, though we cannot explain why
it is so—_i.e._, practice outstrips theory. Again, as a result of
experimental investigation, certain facts are discovered which explain
why the practical methods just alluded to are the best, and this in
turn suggests further improvements in our practice—_i.e._, theory
outstrips practice and enlarges its domain. Thus outstripping theory,
the practical advance made by Lister was an example of the first. His
striking results in turn stimulated scientific observers to make new
discoveries of the greatest importance, and thus science immensely
improved and widened our practical methods.
No definite year or day can be assigned as the birth-date of Lord
Lister’s antiseptic methods, as we can, for instance, for vaccination
or for anæsthesia. We may assume, at least for this country, the
summer of 1876 as the starting-point. During that year Lord Lister
attended the International Medical Congress held in Philadelphia,
and demonstrated his then methods and convinced a few surgeons of
their immense advantages. Even before that date there had been very
many experiments and observations, especially on the blood. In 1863
Davaine, in France, had discovered little rod-like bodies in the
blood in wool-sorters’ disease, or anthrax, which he named from their
shape “bacteria,” or “little rods.” This name has been adopted for
all forms of germs, though many of them are not rod-like in their
shape. Not until 1881 was the cause of inflammation and suppuration
(the formation of pus or “matter”) discovered. In that year Ogston, of
Aberdeen, published experiments which he believed demonstrated the
fact that certain bacteria were the cause of suppuration. Since then
this has been amply confirmed not only by experiments upon animals,
but by observation in man. In 1882 Robert Koch, of Berlin, discovered
the cause of tuberculosis, a little rod-like body, which is named the
“bacillus” of tuberculosis. In 1883 Fehleisen discovered the germ
of erysipelas, and in 1887 Nicolaier and Rosenbaum discovered the
bacillus of tetanus or lockjaw. So recent have been the discoveries
in bacteriology which have led to vast improvements in our methods of
treatment of wounds and the performance of operations.
While the principles established by Lord Lister have remained
unchanged, the details in the treatment have been greatly simplified
and made more efficient. For the information of the general reader, let
me state a few facts. Bacteria are divided into two principal classes,
in accordance with their form. One, known as “cocci,” from the Greek
word coccus—“berry”—may be likened to billiard-balls. Some of these
occur in bunches, which have been likened to bunches of grapes, and
hence are called, again from a Greek term, “staphylococci.” Others are
arranged in chains, like beads, and are called “streptococci.” These
last are very much more virulent and dangerous than the staphylococci.
Both of these produce pus or matter, and they are the most widely
diffused and most common forms found in infected or suppurating
wounds. One form is the cause of erysipelas. A second form, known as
“bacilli,” may be likened to a lead-pencil. Among the various bacilli
that have been discovered are those of tuberculosis, glanders, tetanus
or lockjaw, etc. I omit many others found in medical disorders, as they
do not concern this paper. How important these discoveries are may be
seen by the following facts: Tuberculosis, next to that of suppuration,
is, perhaps, the most widely extended infection to which man, as
well as animals, is liable. We are all familiar with it in the form
of “consumption,” but the non-medical reader is, perhaps, not aware
of the fact that it affects not only the lungs, but also the bowels
in consumption of the bowels; the bones, as is seen by every surgeon
almost daily, and especially as the cause of the crooked backs seen
in spine diseases; in the joints, as is seen in hip-joint disease,
white swelling of the knee, ankle-joint disease, and similar disease
of all the other large joints of the body; in the brain, in tubercular
meningitis; in the abdominal cavity, in tubercular peritonitis; in
the skin, in certain forms of ulceration, commonly called lupus; in
the glands, as in the swollen glands, or “bunches,” in the neck, and
endless other varieties which I need not name.
The bacillus of lockjaw is found in great abundance around stables, and
this explains the fact that hostlers, drivers, cavalrymen, all of whom
had to do with horses, are especially liable to attacks of lockjaw.
Moreover, certain bacteria thrive best when exposed to the open air.
Other bacteria, and among them the bacilli of lockjaw, thrive best when
the air is excluded, and this explains the danger of treading on a
rusty nail, which is popularly and rightly known as peculiarly liable
to produce lockjaw. The reason is not because it is a nail, nor because
it is old, nor because it is rusty, but because from the earth in which
it lies it is most apt to be the means of introducing into a punctured
wound the bacilli of lockjaw. Such a wound bleeds but very little, the
blood soon crusts and excludes the air, and if any of the bacilli of
lockjaw have been carried into the body, they find in such a closed
wound, from which the air is excluded, the most favorable conditions
for growth and infection of the whole body. Knowing these facts from
experiment, the treatment is clear. Lay open such a wound and disinfect
it.
These two forms, the “cocci,” or berry-like bacteria, and the
“bacilli,” or rod-like bacteria, comprise the great majority of
dangerous bacteria.
It must be remembered that there is an enormous number of bacteria
which are not dangerous; some of them are entirely harmless even
if introduced into the human body. Others are the bacteria of
decomposition, or putrefaction, which are known as “saprophytic”
bacteria. All of the harmless ones are known as “non-pathogenic,” that
is, non-producers of disease. Those which produce disease are known
as “pathogenic,” and those which produce suppuration as “pyogenic” or
pus-producing bacteria.
All of these bacteria are plants, and not, as is very frequently
supposed, animals of a low form. The danger from their introduction
into the body can be best appreciated, perhaps, by the statement
of Belfield, who estimated that a single bacterium which weighs,
approximately, only the 1-40,000,000 part of a grain, if given plenty
of food and plenty of “elbow room,” would so rapidly develop that in
three days it would form a mass weighing 800 tons! It is the old story
of the blacksmith who was to get a penny for the first nail, two for
the second, four for the third, and so on till a set of shoes would
cost more than Crœsus could pay for.
The effect of the bacteria has been determined by experiment to be
proportionate to the dose. A cubic centimetre is a cube two-fifths
of an inch on each side. One-tenth of such a cube of pure culture of
one bacterium (_Proteus vulgaris_) contains 225,000,000 bacteria,
and if injected under the skin of a rabbit will produce death.
Less than 18,000,000 will produce no effect whatever. Of one kind
of staphylococcus, if 250,000,000 are introduced under the skin of
a rabbit there will be produced a small abscess, but it requires
1,000,000,000 to produce speedy death. On the other hand, of the
bacillus of lockjaw it requires only 1000 to produce death, so virulent
is this germ.
Moreover, their effect on tissues and persons in different states
varies very much. Thus, it is found that when a certain number of
bacteria are injected into the cavity of the abdomen of an animal, if
the animal is healthy and the peritoneum (the thin lining membrane
of the abdomen) is healthy, the animal will recover perfectly well;
but if the peritoneum be scraped and torn (and it must be remembered
that the healthy peritoneum is devoid of sensation), that the same
dose which before was harmless will now produce a violent peritonitis
and very likely death. The practical lesson from this experiment upon
animals is very evident. Every surgeon who opens the abdomen is most
careful, if possible, not to injure the peritoneum, but manipulates
with the greatest care lest fatal results follow any serious injury
to that membrane. So, too, if the general health be impaired, it is
found that an injection from which a healthy animal would recover will
be followed by fatal consequences if the general health is below par.
Again, if an animal has a simple fracture of his thigh-bone, and that
is the only injury that he receives, no infection from the exterior
having occurred, he will make a good recovery; but if at the same time
he receives a lacerated wound, it may be even in another part of the
body, and this wound, not being cared for most scrupulously, becomes
infected, the infection will fasten on the distant spot of least
resistance, the broken thigh-bone, and will produce a most dangerous
and very frequently fatal form of inflammation.
I need scarcely point out in this connection, as in fact throughout
this entire consideration of bacteriology, how important a part in
its development has been played by experiment upon animals. The
experimental facts just stated are of vital importance in the treatment
of surgical diseases, and evidently could not have been determined
upon mankind. It is not too much to say that had vivisection been
restricted or prohibited the surgery of to-day would be the barbarous
surgery of thirty years ago.
Even granting that an enormous number of the bacteria are harmless,
the wonder is that with so many foes on every hand we live an ordinary
lifetime. Fortunately, however, in the human body there is not only a
lack of food sufficient and “elbow room” enough for them to work their
dire effects, but there is that which “makes for righteousness” in our
physical organization as well as in our souls.
The moment that bacteria are introduced into the human body a certain
number of cells hasten to destroy them. These are called “phagocytes”
or devouring cells, because they eat up the bacteria. Whether the
patient survives or dies depends on whether the bacteria get the upper
hand of the phagocytes or the phagocytes the upper hand of the bacteria.
These statements are very easy to make, but the results have only been
obtained by prolonged and laborious investigations in the laboratory
and by experiments upon animals which have demonstrated these facts.
The bacteria are recognized by various methods: First, by form. Many
which are identical in appearance, however, differ greatly in effects.
A handful of turnip-seed and a handful of rape-seed look very much
alike, but if they are planted the plants differ so greatly that we can
recognize the difference in the seed by the difference in the crop;
hence the second method of recognizing differences in bacteria is by
planting them. Different methods have been practised. Some are sown on
the raw surface of a potato; others on bread paste; others in certain
jelly-like materials, such as gelatine or agar-agar. It was soon found
as a result of these experiments that the bacteria flourished best,
some in one soil, some in another. Again, the crops of mould which come
from them differ greatly in color, some being black, some red, some
white, some yellow, etc. A third method also is by staining them with
various dyes, when it is found that some bacteria will take one stain
best, others will take another, and so on through the whole list.
At first it was thought that these bacteria existed chiefly in the air,
and hence in Lister’s early methods powerful spray-producing apparatus
were used; but while it is true that they do exist in the air, it is
found that this is not the principal source of infection. There is no
substance (which has not been disinfected) that is not covered with
the germs of these little plants. They exist in our food and drink;
but the intestine is, one may say, a natural home in which many exist
without harm to the body. For surgical purposes their existence is most
important, first, in the earth, where, as I have already shown, the
bacillus of lockjaw is most frequently found. So, too, the bacillus of
wool-sorters’ disease (_Anthrax_) exists in the earth. If an animal
dying of anthrax is buried, worms coming from the carcass up through
the ground carry the infection, so that other animals grazing over
this surface will become readily infected. The means by which we can
avoid infection from the earth is very evident, viz., every person
who has been run over by the cars or who has fallen on the ground and
broken his leg, etc., must have the wound most carefully cleansed from
all dirt. If this is scrupulously done the danger of tetanus or other
similar earth-born bacterial disease is almost nothing.
A still greater danger to every patient, however, is found in the
clothing, in the skin, and all dressings which are applied to wounds.
The skin is full of bacteria of the most dangerous kind; even the
spotless hands of the bride, in the eyes of the surgeon, are dirty.
No one can touch a wound with ordinarily clean hands without infecting
it. All clothing, dressings—_e.g._, lint and soft linen rags, and such
like—are full of bacteria of the most dangerous kind. Perhaps the most
dangerous place is the space under the nails of the surgeon’s hand, for
the mere mechanical removal of any dirt under the nails by cleansing
them does not make them clean surgically. The nails must be cut short
and prepared in a way I shall mention directly, or they are full of
peril to any patient into whose wound a non-disinfected finger is
introduced. Again, another source of infection which thirty years ago
we never thought of is our instruments. Then instruments were washed
with soap and water and were made clean to the eye, but they were still
covered with invisible death-dealing bacteria which hid especially in
the joints and irregularities of the surface of all instruments.
All of these somewhat detailed statements lead up to a consideration
of the difference between the old surgery and the new. Thirty years
ago when an operation was to be performed or an accident cared for we
laid out our instruments which were visibly clean, used them with hands
which were as clean as those of any gentleman, and applied soft linen
rags, lint, and other dressings. To-day we know that these apparently
clean instruments, hands, and dressings are covered with bacteria,
which produce infection, and, therefore, suppuration, and frequently
run riot in blood-poisoning, erysipelas, lockjaw, and death.
How does a modern surgeon perform an operation? All bacteria can be
killed by heat. Cold has no effect upon them, but the temperature of
boiling water (212° Fahr.) is sufficient to destroy them all usually
within fifteen or twenty minutes; hence, first, instruments are all
boiled; and, secondly, dressings are either steeped in such solutions
as have been found to destroy the bacteria, such as carbolic acid or
corrosive sublimate, or other preparations, or, still better, are
placed in sterilizers, that is to say, metal cylinders, which are
then filled with steam, usually under pressure, so as to obtain a
temperature of 240° Fahr., and thus make sure of the death of the
bacteria. Unfortunately, our hands cannot be boiled or steamed, but
the modern surgeon first uses soap and water most vigorously over
his hands and arms up to the elbow. The nails are cut short and the
scrubbing-brush is especially applied to the nails so as to clean the
fingers at the ends. Then by various means, such as pure alcohol, which
is one of our best disinfectants, or solutions of corrosive sublimate,
and other means too technical to mention, the hands are sterilized.
Rubber gloves are frequently used, so as to preclude infection, as they
can be steamed to 240° Fahr. Removing at least his outer clothing, the
surgeon puts on a cotton gown which has been steamed and so made free
from bacteria. Not a few surgeons also wear sterilized caps, so that
any bacteria in the hair will not be sifted into a wound, and some wear
respirators of sterile gauze over the mouth and beard for the same
reason. All the dressings have been sterilized by superheated steam.
All the threads by which blood-vessels are tied have been either boiled
or otherwise sterilized. All the material for sewing up the wounds, and
the needles with which they are sewn, have been similarly disinfected.
The skin of the patient is also sterilized, usually the day beforehand,
in the same manner in which the surgeon’s hands have been disinfected,
and are disinfected a second time just at the moment of the operation.
If the case is one of accident, such as a crushed leg from a
trolley-car, all of the dirt is most carefully washed away with soap
and water, and the parts are disinfected, not only on the exterior, but
also by prolonged washing with some cleansing agent in the interior of
the wound, the patient being under the influence of ether, of course.
It is easily seen from such a description of a modern operation that no
case can receive due care in one of our modern homes, even the best.
The facilities do not exist, and hence surgeons are more and more
declining to do operations, whether for accident or disease, in private
houses, except in a case of absolute necessity, and a happy custom
is growing more and more in favor with the community of having all
operations and all accidents cared for in a well-equipped hospital.