individual "has lost his nerve," is afraid to undertake things, shrinks
from responsibility, exaggerates the difficulties that may be in the
way; hence the floods of tears, or outbursts of temper, with which
nervous children will greet the suggestion of any task or duty, however
trifling. If the nervous individual has reached that stage of maturity
when she realizes that she is not merely "naughty," but sick, then this
same process applies itself to her disease. She is sure that she is
going to die, that another attack like that will end in paralysis; as a
patient of mine once expressed it to me, "My heart jumps up in my mouth,
I bite a couple of pieces off it, and it falls back again." In short,
she so obviously and grossly exaggerates every symptom and phase of her
disease, that the impression irresistibly arises that the disease itself
is a fabrication. This view of her condition by her family or her
physician is the tragedy of the neurasthenic.

Broadly speaking, _no_ disease, even of the nervous system, is ever
purely imaginary. Some part of the patient's nervous system is poisoned,
or he would not imagine himself to be sick. We can all of us find
trouble enough in some part of our complex bodily machinery, if we go
around hunting for it; but this is precisely what the healthy man, or
woman, _never_ does. They have other things to occupy them, and are far
more liable to run into danger by pushing ahead at full steam, and
neglecting small creakings and jarrings until something important in the
gear jams, or goes snap, and brings them to a halt, than they are to be
wasting time and energy worrying over things that may never happen.

Worry, in fact, is a sign of disease instead of a cause. To put it very
crudely, whenever the blood and fluids of a body become impoverished
below a certain degree, or become loaded with fatigue poisons, or other
waste products above a certain point, then the nervous system proceeds
to make itself felt. Either the perceptive end-organs become color-blind
and read yellow for blue, or are astigmatic and report oval for round;
or the conducting nerve-strands tangle up the messages, or deliver them
to the wrong centre; or the central clearing-house, puzzled by the
crooked messages, loses its head, and begins to throw the inkstands
about, or goes down in a sulk. In other words, the nervous system goes
on a strike. But it is perfectly idle to endeavor to treat it with
cheering words, or kindly meant falsehoods, to the effect that "nothing
is really the matter." Like any other strike, it can be rationally dealt
with only by improving the conditions under which the operatives have to
work, and meeting their demands for higher wages, or shorter hours.

We were accustomed at one time to divide diseases into two great
classes, organic and functional. By the former, we meant those in which
there was some positive defect of structure, which could be recognized
by the eye or the microscope; by the latter, those diseases in which
this could not be discovered, in which, so to speak, the machine was all
right, but simply wouldn't work. It goes without saying that the latter
class was simply a confession of our ignorance, and one which is
steadily and rapidly diminishing as science progresses.

If the machine won't work, there is a reason for it somewhere, and our
business is to find it out, and not loftily to assure our patients that
there is nothing much the matter, and all they need is rest, or a little
cheerful occupation. Furthermore, the most inane thing that a
sympathizing friend or kindly physician can do to a neurasthenic, is to
advise him to take his mind off himself or his symptoms. The utter
inability to do that very thing is one of the chief symptoms of the
disease, which will not disappear until the underlying cause has been
carefully studied out and removed.

"Nerves," "neurasthenia," "psychasthenia," and "hysteria," are all the
names of _symptoms_ of _definite bodily disease_. The modern physician
regards it as his duty to study out and discover the nature of this
disease, and, if possible, remove it, rather than to give high-sounding,
soul-satisfying names to the symptoms, and advise the patient to "cheer
up"; which advice costs nothing--and is worth just what it costs.

"But," some one will say at once, "if nervous diseases are simply the
reflection of general bodily states, as sanitary conditions improve
under civilization, should they not become less frequent? And yet, any
newspaper will tell you that nervous diseases are rapidly on the
increase." This is a widespread belief, not only on the part of the
public, but of many scientists and a considerable number of physicians;
but it is, I believe, unfounded.

In the first place, we have no reliable statistical basis for a positive
statement, either one way or another. Our ignorance of the precise
prevalence of disease in savagery, in barbarism, and even under
civilization up to fifty years ago, is absolute and profound. It is only
since 1840 that vital statistics of any value, except as to gross deaths
and births, began to be kept. So far as we are able to judge from our
study of savage tribes by the explorer, the army surgeon, and the
medical missionary, the savage nervous system is far less well balanced
and adjustable than that of civilized man. Hysteria, instead of
occurring only in individual instances, attacks whole villages and
tribes. In fact, the average savage lives in a state alternating between
naïve and childish self-satisfaction and panic-stricken terror, with
their resultant cowardice and cruelty on the one hand, and unbridled
lust and delusions of grandeur on the other. The much-vaunted strain of
civilization upon the nervous system is not one-fifth that of savagery.

Think of living in a state when any night might see your village raided,
your hut burned, yourself killed or tortured at the stake, and your wife
and children carried into slavery. Read the old hymns and see how
devoutly thankful our pious ancestors _were every day_ at finding
themselves alive in the morning,--"Safely through another night,"--and
fancy the nerve-strain of never knowing, when you lay down to sleep,
whether some one of the djinns, or voodoos, or vampires would swoop down
upon you before morning. Think of facing death by famine every winter,
by drought or cyclone every summer, and by open war or secret
scalp-raid every month in the year; and then say that the racking
nerve-strain of the commuter's time-table, the deadly clash of the
wheat-pit, or the rasping grind of office-hours, would be ruinous to the
uncivilized nervous system. Certainly, in those belated savages, the
dwellers in our slums, hysteria, diseases of the imagination, enjoyment
of ill health, and the whole brood of functional nervous disturbances
are just as common as they are on Fifth Avenue.

It is not even certain that insanity is increasing. Insanity is quite
common among savages; just how common is difficult to say, on account of
their peculiar methods of treating it. The stupid and the dangerous
forms are very apt to be simply knocked on the head, while the more
harmless and fantastic varieties are turned into priests and prophets
and become the founders of the earlier religions. A somewhat similar
state of affairs of course prevailed among civilized races up to within
the last three-quarters of a century. The idiot and the harmless lunatic
were permitted to run at large, and the latter, as court and village
fools, furnished no small part of popular entertainment, since organized
into vaudeville. Only the dangerous or violent maniacs were actually
shut up; consequently, the number of insane in a community a century ago
refers solely to this class. Hence, in every country where statistics
have been kept, as larger and larger percentages of these unfortunates
have been gathered into hospitals, where they can be kindly cared for
and intelligently treated, the number of the registered insane has
steadily increased up to a certain point. This was reached some fifteen
years ago in Great Britain, in Germany, in Sweden, and in other
countries which have taken the lead in asylum reform, and has remained
practically stationary since, at the comparatively low rate of from two
to three per thousand living. This limit shows signs of having been
reached in the United States already; and this gradual increase of
recognition and registration is the only basis for the alleged increase
of insanity under modern conditions.

It is also a significant fact that the lower and less favorably situated
stratum of our population furnishes not only the largest number of
inmates, but the largest percentage of insanity in proportion to their
numbers, while the most highly educated and highly civilized classes
furnish the lowest. Immigrants furnish nearly three times as many
inmates per thousand to our American asylums as the native born.

It is, however, true that in each succeeding census a steadily
increasing number and percentage of the deaths is attributed to diseases
of the nervous system. This, however, does not yet exceed fifteen or
twenty per cent of the whole, which would be, so to speak, the natural
probable percentage of deaths due to failure of one of the five great
systems of the body: the digestive, the respiratory, the circulatory,
the glandular, the nervous. Two elements may certainly be counted upon
as contributing in very large degree to this apparent increase. One is
the enormous saving of life which has been accomplished by sanitation
and medical progress during the first five years of life, infant
mortality having been reduced in many instances fifty to sixty per
cent, thus of course leaving a larger number of individuals to die later
in life by the diseases especially of the blood-vessels, kidneys, and
nervous system, which are most apt to occur after middle life. The other
is the great increase in medical knowledge, resulting in the more
accurate discovery of the causes of death, and a more correct reporting
and classifying of the same.

In short, a careful review of all the facts available to date leads us
decidedly to the conclusion that the nervous system is the toughest and
most resisting tissue of the body, and that its highest function, the
mind, has the greatest stability of any of our bodily powers. Only one
man in six dies of disease of the nervous system, as contrasted with
nearly one in three from diseases of the lungs; and only one individual
in four hundred becomes insane, as contrasted with from three to ten
times that number whose digestive systems, whose locomotor apparatus,
whose heart and blood-vessels become hopelessly deranged without
actually killing them.

CHAPTER XIX

MENTAL INFLUENCE IN DISEASE, OR HOW THE MIND AFFECTS THE BODY

One of the dearest delusions of man through all the ages has been that
his body is under the control of his mind. Even if he didn't quite
believe it in his heart of hearts, he has always wanted to. The reason
is obvious. The one thing that he felt absolutely sure he could control
was his own mind. If he couldn't control that, what could he control?
Ergo, if man could control his mind and his mind could control his body,
man is master of his fate. Unfortunately, almost in proportion as he
becomes confident of one link in the chain he becomes doubtful of the
other. Nowadays he has quite as many qualms of uncertainty as to whether
he can control his mind as about the power of his mind over his body. By
a strange paradox we are discovering that our most genuine and lasting
control over our minds is to be obtained by modifying the conditions of
our bodies, while the field in which we modify bodily conditions by
mental influence is steadily shrinking.

For centuries we punished the sick in mind, the insane, loading them
with chains, shutting them up in prison-cells, starving, yes, even
flogging them. We exorcised their demons, we prayed over them, we argued
with them,--without the record of a single cure. Now we treat their
sick and ailing bodies just as we would any other class of chronic
patients, with rest, comfortable surroundings, good food, baths, and
fresh air, correction of bad habits, gentleness, and kindness, leaving
their minds and souls practically without treatment, excepting in so far
as ordinary, decent humanity and consideration may be regarded as mental
remedies,--and we cure from thirty to fifty per cent, and make all but
five per cent comfortable, contented, comparatively happy.

We are still treating the inebriate, the habitual drunkard, as a minor
criminal, by mental and moral means--with what hopeful results let the
disgraceful records of our police courts testify. We are now treating
truancy by the removal of adenoids and the fitting of glasses; juvenile
crime by the establishment of playgrounds; poverty and pauperism by
good food, living wages, and decent surroundings; and all for the first
time with success.

In short, not only have all our substantial and permanent victories over
bodily ills been won by physical means, but a large majority of our
successes in mental and moral diseases as well. Yet the obsession
persists, and we long to extend the realm of mental treatment in bodily
disease.

That the mind does exert an influence over the body, and a powerful one,
in both health and disease, is obvious. But what we are apt to forget is
that the whole history of the progress of medicine has been a record of
diminishing resort to this power as a means of cure. The measure of our
success and of our control over disease has been, and is yet, in exact
proportion to the extent to which we can relegate this resource to the
background and avoid resorting to it. Instead of mental influence being
the newest method of treatment it is the oldest. Two-thirds of the
methods of the shaman, the witch-doctor, the medicine-man, were psychic.
Instead of being an untried remedy, it is the most thoroughly tested,
most universal, most ubiquitous remedy listed anywhere upon the pages of
history, and, it may be frankly stated, in civilized countries, as
widely discredited as tested. The proportion to which it survives in the
medicine of any race is the measure of that race's barbarism and
backwardness. To-day two of the most significant criteria of the measure
of enlightenment and of control over disease of either the medical
profession of a nation or of an individual physician are the extent to
which they resort to and rely upon mental influence and opium.
Psychotherapy and narcotics are, and ever have been, the sheet-anchors
of the charlatan and the miracle-worker.

The attitude of the medical profession toward mental influence in the
treatment of disease is neither friendly nor hostile. It simply regards
it as it would any other remedial agency, a given drug, for instance, a
bath, or a form of electricity or light. It is opposed to it, if at all,
only in so far as it has tested it and found it inferior to other
remedies. Its distrust of it, so far as this exists, is simply the
feeling that it has toward half a hundred ancient drugs and remedial
agencies which it has dropped from its list of working remedies as
obsolete, many of which still survive in household and folk medicine. My
purpose is neither to champion it nor to discredit it, and least of all
to antagonize or throw doubt upon any of the systems of philosophy or of
religion with which it has been frequently associated, but merely to
attempt to present a brief outline of its advantages, its character, and
its limitations, exactly as one might of, say, calomel, quinine, or
belladonna.

As in the study of a drug, the chief points to be considered are: What
are its actual powers? What effects can be produced with it, both in
health and sickness? What are the diseases in which such effects may be
useful, and how frequent are they? In what way does it produce its
effects, directly or indirectly?

The first and most striking claim that is made for mental influence in
disease is based upon the allegation that it has the power of producing
disease and even death; the presumption, of course, being that, if able
to produce these conditions, it would certainly have some influence in
removing or preventing them. Upon this point the average man is
surprisingly positive and confident in his convictions. Popular
literature and legend are full of historic instances where individuals
have not merely been made seriously ill but have even been killed by
powerful impressions upon their imaginations. Most men are ready to
relate to you instances that have been directly reported to them of
persons who were literally frightened to death. But the moment that we
come to investigate these widely quoted and universally accepted
instances, we find ourselves in a curious position. On the one hand,
merely a series of vague tales and stories, without date, locality,
name, or any earmark by which they can be identified or tested. On the
other, a collection of rare and extraordinary instances of sudden death
which have happened to be preceded by a powerful mental impression, many
of which bear clearly upon their face the imprint of death by rupture of
a blood-vessel, heart failure, or paralysis, in the course of some
well-marked and clearly defined chronic disease, like valvular
heart-mischief, diabetes, or Bright's disease.

Upon investigation most of these cases which have been seen by a
physician previous to death have been recognized as subject to a disease
likely to terminate in sudden death; and practically all in which a
post-mortem examination has been made have shown a definite physical
cause of death. The fright, anger, or other mental impression, was
merely the last straw, which, throwing a sudden strain upon already
weakened vessels, heart, or brain, precipitated the final catastrophe.
In some cases, even the sense of fright and the premonition of
approaching death were merely the first symptoms of impending
dissolution.

The stories of death from purely imaginative impressions, such as the
victims being told that they were seriously ill, that they would die on
or about such and such a date, fall into two great classes. The first of
these--involving death at a definite date, after it had been prophesied
either by the victim or some physician or priest--may be dismissed in a
few words, as they lead at once into the realm of prophecy, witchcraft,
and voodoo. Most of them are little better than after-echoes of the
ethnic stories of the "evil eye," and of bewitched individuals fading
away and dying after their wax image has been stuck full of pins or
otherwise mutilated. There have occurred instances of individuals dying
upon the date at which some one in whose powers of prophecy they had
confidence declared they would, or even upon a date on which they had
settled in their own minds, and announced accordingly; but these are so
rare as readily to come within the percentage probabilities of pure
coincidence. Most such prophecies fail utterly; but the failures are not
recorded, only the chance successes.

The second group of these alleged instances of death by mental
impression is in most singular case. Practically every one with whom you
converse, every popular volume of curiosities which you pick up, is
ready to relate one or more instances of such an event. But the more you
listen to these relations, the more familiar do they become, until
finally they practically simmer down to two stock legends, which we have
all heard related in some form.

First, and most famous, is the story of a vigorous, healthy man accosted
by a series of doctors at successive corners of the street down which he
is walking, with the greeting:--

"Why, my dear Mr. So-and-So, what is the matter? How ill you look!"

He becomes alarmed, takes to his bed, falls into a state of collapse,
and dies within a few days.

The other story is even more familiar and dramatic. Again it is a group
of morbidly curious and spiteful doctors who desire to see whether a
human being can be killed by the power of his imagination. A condemned
criminal is accordingly turned over to them. He is first allowed to see
a dog bled to death, one of the physicians holding a watch and timing
the process with, "Now he is growing weaker! Now his heart is failing!
Now he dies!" Then, after having been informed that he is to be bled to
death instead of guillotined, his eyes are bandaged and a small,
insignificant vein in his arm is opened. A basin is held beneath his
arm, into which is allowed to drip and gurgle water from a tube so as to
imitate the sounds made by the departing life-blood. Again the
death-watch is set and the stages of his decline are called off: "Now he
weakens! Now his heart is failing!" until finally, with the solemn
pronouncement, "Now he dies!" he falls over, gasps a few times and is
dead, though the total amount of blood lost by him does not exceed a few
teaspoonfuls.

A variant of the story is that the trick was played for pure mischief in
the initiation ceremonies of some lodge or college fraternity, with the
horrifying result that death promptly resulted.

The stories seem to be little more than pure creatures of the same force
whose power they are supposed to illustrate, amusing and dramatic
fairy-tales, handed down from generation to generation from Heaven knows
what antiquity. Death under such circumstances as these _may_ have
occurred, but the proofs are totally lacking. One of our leading
neurologists, who had extensively experimented in hypnotism and
suggestion, declared a short time ago: "I don't believe that death was
ever caused solely by the imagination."

Now as to the scope of this remedy, the extent of the field in which it
can reasonably be expected to prove useful. This discussion is, of
course, from a purely physical point of view. But it is, I think, now
generally admitted, even by most believers in mental healing, that it is
only, at best, in rarest instances that mental influence can be relied
upon to cure organic disease, namely, disease attended by actual
destruction of tissue or loss of organs, limbs, or other portions of the
body. This limits its field of probable usefulness to the so-called
"functional diseases," in which--to put it crudely--the body-machine is
in apparently perfect or nearly perfect condition, but will not work;
and particularly that group of functional diseases which is believed to
be due largely to the influence of the imagination.

Nowhere can the curious exaggeration and over-estimation of the real
state of affairs in this field be better illustrated than in the popular
impression as to the frequency in actual practice of "imaginary"
diseases. Take the incidental testimony of literature, for instance,
which is supposed to hold the mirror up to nature, to be a transcript of
life. The pages of the novel are full, the scenes of the drama are
crowded with imaginary invalids. Not merely are they one of the most
valuable stock properties for the humorist, but whole stories and
comedies have been devoted to their exploitation, like Molière's classic
"Le Malade Imaginaire," and "Le Médecin Malgré Lui." Generation after
generation has shaken its sides until they ached over these pompous old
hypochondriacs and fussy old dowagers, whose one amusement in life is to
enjoy ill health and discuss their symptoms. They are as indispensable
members of the _dramatis personæ_ of the stock company of fiction as the
wealthy uncle, the crusty old bachelor, and the unprotected orphan. Even
where they are only referred to incidentally in the course of the story,
you are given to understand that they and their kind furnish the
principal source of income for the doctor; that if he hasn't the tact to
humor or the skilled duplicity to plunder and humbug these self-made
sufferers, he might as well retire from practice. In short, the entire
atmosphere of the drama gives the strong impression that if
people--particularly the wealthy classes--would shake themselves and go
about their business, two-thirds of the illness in the world would
disappear at once.

Much of this may, of course, be accounted for by the delicious and
irresistible attractiveness, for literary purposes, of this type of
invalid. Genuine, serious illness, inseparable from suffering and ending
in death, is neither a cheerful, an interesting, nor a dramatic episode,
except in very small doses, like a well-staged death-bed or a stroke of
apoplexy, and does not furnish much valuable material for the novelist
or the play-writer. Battle, murder, and sudden death, while horrible
and repulsive, can be contemplated with vivid, gruesome interest, and
hence are perfectly available as interest producers. But much as we
delight to talk about our symptoms, we are never particularly interested
in listening to those of others, still less in seeing them portrayed
upon the stage. On account of their slow course, utter absence of
picturesqueness, and depressing character, the vast majority of diseases
are quite unsuitable for artistic material. In fact, the literary worker
is almost limited to a mere handful, at one extreme, which will produce
sudden and dramatic effects, like heart failure, apoplexy, or the
ghastly introduction of a "slow decline" for a particularly pathetic
effect; and at the other extreme, those imaginary diseases, migraines
and vapors, which furnish amusement by their sheer absurdity.

Be that as it may, such dramatic and literary tendencies have produced
their effect, and the popular impression of the doctor is that of a man
who spends his time between rushing at breakneck speed to save the lives
of those who suddenly find themselves _in articulo mortis_ and will
perish unless he gets there within fifteen minutes, and dancing
attendance upon a swarm of old hypochondriacs, neurotics, and nervous
dyspeptics, of both sexes. As a matter of fact, these two supposed
principal occupations of the doctor are the smallest and rarest elements
in his experience.

A few years ago a writer of world-wide fame deliberately stated, in the
course of a carefully considered and critical discussion of various
forms of mental healing, that it was no wonder that these methods
excited huge interest and wide attention in the community, because, if
valid, they would have such an enormous field of usefulness, seeing that
at least seven-tenths of all the suffering which presented itself for
relief to the doctor was imaginary.

This, perhaps, is an extreme case, but is not far from representing the
general impression. If a poll were to be taken of five hundred
intelligent men and women selected at random, as to how much of the
sufferings of all invalids, or sick people who are not actually
obviously "sick unto death" or ill of a fever, was real and how much
imaginary, the estimate would come pretty close to an equal division.
But when one comes to try to get at the actual facts, an astonishingly
different state of affairs is revealed. I frankly confess that my own
awakening was a matter of comparatively recent date.

A friend of mine was offered a position as consulting physician to a
large and fashionable sanatorium. He hesitated because he was afraid
that much of his time would be wasted in listening to the imaginary
pains, and soothing the baseless terrors, of wealthy and fashionable
invalids, who had nothing the matter with them except--in the language
of the resort--"nervous prosperity." His experience was a surprise. At
the end of two years he told me that he had had under his care between
six and seven hundred invalids, a large percentage of whom were drawn
from the wealthier classes; and out of this number there were _only
five_ whose sufferings were chiefly attributable to their imagination.
Many of them, of course, had comparatively trivial ailments, and others
exaggerated the degree or mistook the cause of their sufferings; but the
vast majority of them were, as he naïvely expressed it, "really sick
enough to be interesting."

This set me to thinking, and I began by making a list of all the
"imaginary invalids" I had personally known, and to my astonishment
raked up, from over twenty years' medical experience, barely a baker's
dozen. Inquiries among my colleagues resulted in a surprisingly similar
state of affairs. While most of them were under the general impression
that at least ten to twenty per cent of the illnesses presenting
themselves were without substantial physical basis and largely imaginary
in character, when they came actually to cudgel their memories for
well-marked cases and to consult their records, they discovered that
their memories had been playing the same sort of tricks with them that
the dramatists and novelists had with popular impressions.

Within the past few months one of the leading neurologists of New York,
a man whose practice is confined exclusively to mental and nervous
diseases, stated in a public address that purely or even chiefly
imaginary diseases were among the rarer conditions that the physician
was called upon to treat. Shortly after, two of the leading neurologists
of Philadelphia, one of them a man of international reputation,
practically repeated this statement; and they put themselves on record
to the effect that the vast majority of those who imagined themselves to
be ill were ill, though often not to the degree or in precisely the
manner that they imagined themselves to be.

Obviously, then, this possible realm of suffering in which the mind can
operate is very much more limited than was at one time believed. In
fact, imaginary diseases might be swept out of existence, and humanity
would scarcely know the difference, so little would the total sum of its
suffering be reduced.

Another field in which there has been much general misunderstanding and
looseness of both thought and statement, which has again led to
exaggerated ideas of the direct influence of the mind over the body, is
the well-known effect of emotional states, such as fright or anger, upon
the ordinary processes of the body. Instances of this relation are, of
course, household words,--the man whose "hair turned white in a single
night" from grief or terror; the nursing mother who flew into a furious
fit of passion and whose child was promptly seized with convulsions and
died the next time it was put to the breast; the father who is
prostrated by the death or disgrace of a favorite son, and dies within a
few weeks of a broken heart. The first thing that is revealed by even a
brief study of this subject is that these instances are exceedingly
rare, and owe their familiarity in our minds to their striking and
dramatic character and the excellent "material" which they make for the
dramatist and the gossip. It is even difficult to secure clear and valid
proof of the actual occurrence of that sudden blanching of the hair,
which has in the minds of most of us been accepted from our earliest
recollection.

More fundamental, however, and vital, is the extent to which we have
overlooked the precise method in which these violent emotional
impressions alter bodily activities, like the secretions. Granting, for
the sake of argument, that states of mind, especially of great tension,
have some direct and mysterious influence as such, and through means
which defy physical recognition and study, it must be remembered that
they have a perfectly definite physiological sphere of influence upon
vital activities. Indeed, we are already in a position to explain at
least two-thirds of these so-called "mental influences" upon purely
physical and physiological grounds.

First of all, we must remember that these emotions which we are pleased
to term "states of mind" are also states of body. If any man were to
stand up before you, for instance, either upon the stage or in private,
and inform you that he was "scared within an inch of his life," without
tremor in his voice, or paling of his countenance, or widening eyes, or
twitching muscles, or preparations either to escape or to fight, you
would simply laugh at him. You would readily conclude, either that he
was making fun of you and felt no such emotion, or that he was
repressing it by an act of miraculous self-control. The man who is
frightened and doesn't do anything or look as if he were going to do
anything, the man who is angry and makes no movement or even twitching
suggesting that fact, is neither angry nor frightened.

An emotional state is, of course, a peculiarly complex affair. First,
there is the reception of the sensation, sight, sound, touch, or smell,
which terrifies. This terror is a secondary reaction, and in ninety-nine
cases out of a hundred is conditioned upon our memory of previous
similar objects and their dangerousness, or our recollection of what we
have been told about their deadliness. Then instantly, irrepressibly,
comes the lightning-flash of horror to our heart, to our muscles, to
our lungs, to get ready to meet this emergency. Then, and not till then,
do we really feel the emotion. In fact, our most pragmatic philosopher,
William James, has gone so far as to declare that emotions are the
after-echoes of muscular contractions. By the time an emotion has fairly
got us in its grip so that we are really conscious of it, the
blood-supply of half the organs in our body has been powerfully altered,
and often completely reversed.

To what extent muscular contractions condition emotions, as Professor
James has suggested, may be easily tested by a quaint and simple little
experiment upon a group of the smallest voluntary muscles in the body,
those that move the eyeball. Choose some time when you are sitting
quietly in your room, free from all disturbing thoughts and influences.
Then stand up and, assuming an easy position, cast the eyes upward and
hold them in that position for thirty seconds. Instantly and
involuntarily you will be conscious of a tendency toward reverential,
devotional, contemplative ideas and thoughts. Then turn the eyes
sideways, glancing directly to the right or to the left, through
half-closed lids. Within thirty seconds images of suspicion, of
uneasiness, or of dislike, will rise unbidden in the mind. Turn the eyes
to one side and slightly downward, and suggestions of jealousy or
coquetry will be apt to spring unbidden. Direct your gaze downward
toward the floor, and you are likely to go off into a fit of reverie or
of abstraction.

In fact, as Darwin long ago remarked, quoting in part from Bain: "Most
of our emotions [he should have said all] are so closely connected with
their expression that they hardly exist if the body remains passive. As
Louis XVI, facing a mob, exclaimed, 'Afraid? Feel my pulse!' so a man
may intensely hate another, but until his bodily frame is affected he
can hardly be said to be enraged."

And, a little later, from Maudsley:--

"The specific muscular action is not merely an exponent of passion, but
truly an essential part of it. If we try, while the features are fixed
in the expression of one passion, to call up in the mind a different
one, we shall find it impossible to do so."

It will also be recollected what an important part in the production of
hypnosis and the trance state, fixed and strained positions of these
same ocular muscles have always been made to play. Many hypnotists can
bring their subjects under their influence solely by having them gaze
fixedly at some bright object like a mirror, or into a crystal sphere,
for a few minutes or even seconds.

A graphic illustration of the importance of muscular action in emotional
states is the art of the actor. Not only would it be impossible for an
actor to make an audience believe in the genuineness of his supposed
emotion if he stood glassy-eyed and wooden-limbed declaiming his lines
in a monotone, without gestures or play of expression of any sort, but
it would also be impossible for him to feel even the counterfeit
sensation which he is supposed to represent. So definite and so well
recognized is this connection, that many actors take some little time,
as they express it, to "warm up" to their part, and can be visibly seen
working themselves up to the pitch of emotion desired for expression by
twitching muscles, contractions of the countenance, and catchings of the
breath. This last performance, by the way, is not by any means confined
to the stage, but may be seen in operation in clashes and disagreements
in real life. An individual who knows his case to be weak, or himself to
be lacking in determination, can be seen working himself up to the
necessary pitch of passion or of obstinacy. There is even a lovely old
fairy-tale of our schoolboy days, which is still to be found in ancient
works on natural history, to the effect that the King of Beasts himself
was provided with a small, horny hook or spur at the end of his tail,
with which he lashed himself into a fury before springing upon his
enemy!

What, then, will be the physical effect of a shock or fright or furious
outburst of anger upon the vital secretions? Obviously, that any
processes which require a full or unusually large share of blood-supply
for their carrying out will be instantly stopped by the diversion of
this from their secreting cells, in the wall of the stomach, in the
liver, or in the capillaries of the brain, to the great muscular masses
of the body, or by some strange, atavistic reflex into the so-called
"abdominal pool," the portal circulation. The familiar results are just
what might have been expected. The brain is so suddenly emptied of blood
that connected thought becomes impossible, and in extreme cases we stand
as one paralyzed, until the terror that we would flee from crashes down
upon us, or we lose consciousness and swoon away. If the process of
digestion happens to be going on, it is instantly stopped, leaving the
food to ferment and putrefy and poison the body-tissues which it would
otherwise have nourished. The cells of the liver may be so completely
deprived of blood as to stop forming bile out of broken-down blood
pigment, and the latter will gorge every vessel of the body and escape
into the tissues, producing jaundice.

Every one knows how the hearing of bad news or the cropping up of
disagreeable subjects in conversation at dinner-time will tend to
promote indigestion instead of digestion. The mechanism is precisely
similar. The disagreeable news, if it concern a financial or executive
difficulty, will cause a rush of blood to the brain for the purpose of
deciding what is to be done. But this diminishes the proper supply of
blood to the stomach and to the digestive glands, just as really as the
paralysis of violent fright or an explosion of furious anger. If the
unpleasant subject is yet a little more irritating and personal, it will
lead to a corresponding set of muscular actions, as evidenced in
heightened color, loud tones, more or less violent gesticulation, with
marked interruption of both mastication and the secretion of saliva and
all other digestive juices. In short, fully two-thirds of the influences
of emotional mental states upon the body are produced by their calling
away from the normal vital processes the blood which is needed for their
muscular and circulatory accompaniments. No matter how bad the news or
how serious the danger, if they fail to worry us or to frighten us,--in
other words, to set up this complicated train of muscular and
blood-supply changes,--then they have little or no effect upon our
digestions or the metabolism of our liver and kidneys.

The classic "preying upon the damask cheek" of grief, and the carking
effect of the Black Care that rides behind the horseman, have a
perfectly similar physical mechanism. While the primary disturbance of
the banking balances of the body is less, this is continued over weeks
and months, and in addition introduces another factor hardly less
potent, by interfering with all the healthful, normal, regular habits of
the body,--appetite, meal-times, sleep, recreation. These wastings and
pinings and fadings away are produced by mental influence, in the sense
that they cannot be cured by medicines or relieved at once by the best
of hygienic advice; but it is idle to deny that they have also a broad
and substantial physical basis, in the extent to which states of
emotional agony, despair, or worry interfere with appetite, sleep, and
proper exercise and recreation in the open air. Just as soon as they
cease to interfere with this normal regularity of bodily functions, the
sufferer begins to recover his health.

We even meet with the curious paradox of individuals who, though
suffering the keenest grief or anxiety over the loss or serious illness
of those nearest or dearest to them, are positively mortified and
ashamed because their countenances show so little of the pallid hues and
the haggard lines supposed to be inseparably associated with grief. So
long as the body-surplus is abundant enough to stand the heavy
overdrafts made on it by grief and mental distress, without robbing the
stomach of its power to digest and the brain of its ability to sleep,
the physical effects of grief, and even of remorse, will be slight.

It must be remembered that loss of appetite is not in itself a cause of
trouble, but a symptom of the stomach's inability to digest food; in
this instance, because it finds that it can no longer draw upon the
natural resources of the body in sufficient abundance to carry out its
operations. The state is exactly like a tightness of the money market,
when, on account of unnatural retention or hoarding in some parts of the
financial field, the accumulation of sufficient amounts of floating
capital at the banks for moving the crop or paying import duties cannot
be carried out as usual. The vital system is, in fact, in a state of
panic, so that the stomach cannot get the temporary credit or capital
which it requires.

A similar condition of temporary panic, call it mental or bodily, as you
will, occurs in disease and is not confined to the so-called imaginary
diseases, or even to the diseases of the nervous system, but is apt to
be present in a large number of acute affections, especially those
attended by pain. Sudden invasion of the system by the germs of
infectious diseases, with their explosions of toxin-shells all through
the redoubts of the body, often induces a disturbance of the bodily
balance akin to panic. This is usually accompanied and aggravated by an
emotional dread and terror of corresponding intensity. The relief of the
latter, by the confident assurance of an expert and trusted physician
that the chances are ten to one that the disease will run its course in
a few days and the patient completely recover,--especially if coupled
with the administration of some drug which relieves pain or diminishes
congestion in the affected organs,--will often do much toward restoring
balance and putting the patient in a condition where the natural
recuperative powers of the system can begin their work. The historic
popularity of opium, and of late of the coal-tar products (phenacetine
and acetanilide), in the beginning of an acute illness, is largely based
on the power which they possess of dulling pain, relieving disturbances
of the blood-balance, and soothing bodily and mental excitement.
Fever-panic or pain-panic, like a banking panic, though it has a genuine
and substantial basis, can be dealt with and relieved much more readily
after checking excessive degrees of distrust and excitement. An opiate
will relieve this physical pain-panic, just as a strong mental
impression will relieve the fright-paralysis and emotional panic which
often accompany it, and thus give a clearer field and a breathing space
for the more slowly acting recuperative powers of nature to assert their
influence and get control of the situation.

_But neither of them will cure._ The utmost that they can do is to give
a breathing spell, a lull in the storm, which the rallying powers of the
body, if present, can take advantage of. If the latter, however, be not
adequate to the situation, the disease will progress to serious or even
fatal termination, just as certainly as if no such influence had been
exerted, and often at an accelerated rate. In fact, our dependence upon
opiates and mental influence have been both a characteristic and a
cause of the Dark Ages of medicine. The more we depended upon these, the
more content we were to remain in ignorance of the real causes of
disease, whether bodily or mental.

The second physical effect produced by mental influence is probably the
most important of all, and that is _the extent to which it induces the
patient to follow good advice_. We as physicians would be the last to
underestimate the importance of the confidence of our patients. But we
know perfectly well that our retention of that confidence will depend
almost entirely upon the extent to which we can justify it; that its
principal value to us lies in the extent to which it will insure prompt
obedience to our orders, and intelligent and loyal coöperation with us
in our fight against disease. The man who would depend upon the
confidence of his patients as a means of healing, would soon find
himself without practice. We know by the bitterest of experience that no
matter how absolute and boundless the confidence of our patients may be
in our ability to heal them, no matter how much they may express
themselves as cheered and encouraged by our presence, ninety-nine per
cent of the chance of their recovery depends upon the gravity of the
disease, the vigor of their powers of resistance, and our skill and
intelligence in combating the one and assisting the other.

Valuable and helpful as courage and confidence in the sick-room are,
they are but a broken reed which will pierce the hand of him who leans
upon it too heavily, be he patient or physician. We can all recall, as
among our saddest and most heart-breaking experiences, the cases of
fatal disease, which were well-nigh hopeless from the start, and yet in
which the sufferers expressed, and maintained to the last moments of
conscious speech, a bright and pathetically absolute confidence in our
powers of healing, based upon our success in some previous case, or upon
their own irrepressible hopefulness.

Even the deadliest and most serious of infectious diseases, consumption,
has--as is well known--as one of its prominent symptoms an irrepressible
hopefulness and confidence that they will get well, on the part of a
considerable percentage of its victims. This has even been formally
designated in the classical medical treatises as the "_Spes Phthisica_,"
or "Consumptive Hope." But these hopeful consumptives die just as surely
as the depressed ones; in fact, if anything, in a little larger
proportion. It well illustrates the other side of the shield of hope and
confidence, the danger of unwavering expectancy, in that it is chiefly
those who are early alarmed and turn vigorously to fight the disease
under intelligent medical direction, who make the recoveries. Too serene
a courage, too profound a confidence in occult forces, is only a form of
fatalism and a very dangerous one.

Broadly speaking, mental states in the sick-room are a pretty fair
index--I don't mind saying, product--of bodily states. Hopefulness and
confidence are usually favorable signs, for the reason that they are
most likely to be displayed by individuals who, although they may be
seriously ill, are of good physique, have high resisting power, and
will make a successful fight against the disease. So, roughly speaking,
courage and hopefulness are good omens, on purely physical grounds.

But these are only rough indications of probabilities, not reliable
signs; and as a rule we are but little affected by either the hopes or
the fears of our patients in making up our estimate of their chances.
The only mental symptom that weighs heavily with us is indifference.
This puts us on the lookout at once. So long as our patients have a
sufficiently vivid and lively fear of impending death, we feel pretty
sure that they are not seriously ill; but when they assure us dreamily
that they "feel first-rate," forget to ask us how they are getting
along, or become drowsily indifferent to the outlook for the future,
then we redouble our vigilance, for we fear that we recognize the
gradual approach of the Great Restbringer, the merciful drowsiness which
in nine cases out of ten precedes and heralds the coming of the Long
Sleep.

Lastly, the cases in which the sufferings of the patient are due chiefly
to a morbid action of his or her imagination, are a small percentage of
the total of the ills which come before us for relief. But, even of this
small percentage, _only a very few are in perfect or even reasonably
good physical health_. A large majority of even these neurasthenics,
psychasthenics, imaginary invalids, and bodily or mental neurotics, have
some physical disturbance, organic or functional, which is the chief
cause of their troubles. And the important point is that our success in
relieving these sufferers will depend upon our skill in ferreting out
this physical basis, and the extent to which we can succeed in
correcting or relieving it. We no longer ridicule or laugh at these
unfortunates. On the contrary we pity them from the bottom of our
hearts, because we know that their sufferings, however polarly remote
they may be from endangering their lives in any way, and however
imaginary in a purely material sense, are _to them_ real. Their
happiness is destroyed and their efficiency is crippled just as
genuinely and effectively as if they had a broken limb or a diseased
heart.

We are now more and more firmly convinced that these patients, however
ludicrously absurd their forebodings, are _really sick_, either bodily
or mentally, and probably both. A perfectly healthy individual seldom
imagines himself or herself to be ill. And as the list of so-called
functional diseases--that is to say, those diseases in which no
definite, objective mark of degeneration or decay in any tissue or organ
can be discovered--are steadily and swiftly diminishing under the
scrutiny of the microscope and the methods of the laboratory, so these
purely imaginary diseases, these "depressed mental states," these
"essential morbid tendencies," are also rapidly diminishing in number,
as cases are more conscientiously and personally studied and worked out.

Even hysteria is no longer looked upon as sheer perversity on the part
of the patient, but is patiently traced back, stage by stage, until if
possible the primary "strangulated emotion" which caused it is
discovered; and where this can be found the whole morbid tendency can
often be relieved and reversed almost as if by magic.

To sum up: My contention is, that the direct influence of emotional
states upon bodily organs and functions has been greatly exaggerated;
that it is exceedingly doubtful whether, for instance, any individual in
a reasonable condition of health was ever killed by an imaginary or even
an emotional shock; that there is surprisingly little valid evidence
that the hair of any human being turned white in a single night, or was
completely shed within a few hours, under the influence of fright,
terror, or grief; that the effects upon bodily functions and secretions,
digestion, etc., produced by emotion, are due to secondary effects of
the latter, diverting the energy of the body into other channels and
disturbing the general balance of its forces and blood-supply; that the
actual percentage of cases in which the imagination plays the chief, or
even a dominant part, is small, probably not to exceed five or ten per
cent; that a very considerable share of the influence of mental
impressions in the cure of disease is due to the relief of mental panic,
permitting the rallying of the recuperative powers of the body, and to
the extent to which they produce the reform of bad physical habits or
surroundings or conditions.

The most important element in the cure of disease by mental
impression is _time_ plus the _vis medicatrix naturæ_. The mental
impression--suggestion, scolding, securing of confidence--diverts the
attention of the patient until his own recuperative power and the
intelligent correction of bad physical habits remedy his defect. Pure
mental impression, however vivid, which is not followed up by
improvement of the environment, or correction of bad physical habits,
will be almost absolutely sterile. Faith without works is as dead in
medicine as in religion. Mental influence is little more than an
introduction committee to real treatment. Even the means used for
producing mental impressions are physical,--impressions made upon some
one of the five senses of the individual. In short, as Barker aptly puts
it, "Every psychotherapy is also a physical therapy."

Furthermore, even mental worry, distress, or depression, in nine cases
out of ten has a physical cause. To remedy conditions of mental stress
by correcting the underpay, overwork, bad ventilation, or underfeeding
on account of illness or death of the wage-earner of the family, is, of
course, nothing but the most admirable common sense; but to call it the
_mental_ treatment of disease is a mere juggling with words. "Take care
of the body and the mind will take care of itself," is a maxim which
will prove valid in actual practice nine times out of ten.

INDEX

  Abernethy, Dr. John, 80.

  Acne, 38.

  Acromegaly, 119.

  Adenoids, 105-122.

  Air, foul, 97.

  Alimentary canal, 274-279.

  Allbutt, Sir Clifford, 134.

  Allen, Dr. Harrison, 120.

  Animals, immune to certain diseases, 255.

  Anti-bodies. _See_ Antitoxins.

  Antisepsis, 333, 336-339.

  Antitoxins, or anti-bodies, 9, 93, 94, 199, 200;
    discovery and use of the diphtheria antitoxin, 230-233, 236, 242, 401;
    tetanus antitoxin, 345, 346, 398.

  Apoplexy, 40, 402.

  Appendicitis, 269-288.

  Appendix, vermiform, 35, 36, 268-270, 273-279.

  Asepsis, 333.

  Asthmatics, 328.

  Attitude, the upright, 76.

  Autointoxication, 376.

  Bacilli. _See_ Bacteria.

  Bacteria, abundance of, in the body, 10, 99.

  Bang, Professor, 148.

  Bath, the cold, 98.

  Bile, in vomiting, 379.

  Bites, danger from, 342.

  Blood, coagulation of, 39, 40.

  Blood-corpuscles, 24-29.

  Blood-poisoning, 331-349.

  Bloodgood, Dr. J. C., 272.

  Bones, nature of, 20, 21.

  Boswell, James, 88.

  Bridge, Dr. Norman, 95.

  Cæcum, 274-278.

  Cancer, a rebellion of the cells, 42, 351;
    heredity and, 50, 51;
    individuality of, 350;
    probable nature of, 351;
    death-rate from, 352, 353;
    natural history of, 353-364;
    not communicable, 357, 358;
    vain search for a parasite, 359, 360;
    a disease of senility, 363, 364;
    problems of prevention and cure, 365, 366.

  Carriage, in illness, 76.

  Cattani, 398.

  Cellular theory of disease, 18, 19.

  Cerebro-spinal meningitis, 397.

  Chantemesse, 221.

  Children's diseases, importance of, 243-245;
    prevention of, 245;
    dangerous results of, 245, 246;
    effect on growth and development, 247;
    reasons for, 248-250;
    occasional severity of, 251-254;
    taming of, 253, 254;
    causes of, 254, 255;
    treatment of, 255, 256;
    symptoms of, 256, 257;
    the three chief, 257-266.

  Cities, disease and death-rate in, 159-165.

  Civilization, and nervousness, 406-408.

  Cleanliness, 98.

  Cohnheim, 364.

  Colds, treatment of, 11, 12, 93-101;
    cause of, 85-93;
    how to catch, 101, 102;
    their relation to rheumatism, 320, 321, 323, 324, 326, 327.

  Colic, 4.

  Color, in diagnosis, 70-74.

  Congenital disease, 44, 45.

  Coughing, use of, 11, 12.

  Darwin, Charles, quoted, 425, 426.

  Diagnosis, 55-82.

  Diarrh[oe]a, use of, 5;
    treatment of, 5.

  Diphtheria, 222-242;
    attacking the nervous system, 400, 401.

  Disease, causes of, 3;
    not absolute but relative, 14;
    former conceptions of, 15-18;
    organic and functional, 405, 406;
    mental influence in, 411-437.

  Drafts, 94, 95, 99.

  Earache, 110.

  Edison, Thomas A., 286.

  Epilepsy, heredity and, 52, 53.

  Erysipelas, 348.

  Eustachian tubes, 109, 110.

  Expectoration, 142, 143.

  Eye-strain, 377.

  Facial expression, in diagnosis, 62-70.

  Fever, meaning of, 7, 8;
    treatment of, 8-11.

  Flick, Dr. Laurence, 96.

  Fly, house, and typhoid, 210, 211.

  Food-tube, the, 274-279.

  Gait, in illness, 76-78.

  Gall-bladder, 37.

  Grip, the, 90.

  Guinea-pig, a burnt offering, 222;
    used in the discovery of the diphtheria antitoxin, 229-231.

  Hand, the, in diagnosis, 73-75.

  Harelip, 37.

  Headache, purpose and meaning of, 12, 13, 367-376;
    treatment of, 370, 371, 381-386;
    from eye-strain, 377, 386;
    from digestive disturbances, 377, 378;
    sick headache, 378, 379, 381;
    from stuffy rooms, 380;
    from sluggish bowels and kidney trouble, 380;
    from loss of sleep, 380, 381;
    from nasal obstruction, 381;
    rest the cure for, 382-384;
    massage for the relief of, 385, 386;
    the nerves affected in, 385, 386.

  Heart, effect of rheumatism on, 314, 315.

  Heredity, in health and disease, 32-54.

  Hernia, 36.

  Holmes, Oliver Wendell, 125.

  Horses, and disease, 344, 345.

  Hospitals, blood-poisoning and antisepsis in, 335-339.

  Humoral theory of disease, 17, 18.

  Huxley, Thomas Henry, quoted, 1, 112, 201.

  Hysteria, 403, 406, 407, 435.

  Imaginary illness, 415-422, 436.

  Immunity, 93.

  Indians, epidemics among, 251, 252.

  Indifference of the dying, 434.

  Infants, diagnosis in the case of, 81, 82.

  Influenza, 90.

  Insanity, heredity and, 52-54;
    among savages and in civilization, 408, 409;
    treatment of, 411, 412.

  Intestines, 274.

  James, William, 425.

  Johnson, Samuel, 89.

  Joints, diseases of, 318, 319.

  King, Dr. Albert F. A., 298.

  Koch, Robert, 126, 152, 153, 155, 156, 228, 308.

  Laveran, 295.

  Lister, Lord, 332.

  Liver, functions of, 6, 7.

  Lockjaw, 344-346, 397, 398.

  Locomotor ataxia, 399; diagnosis of, 77, 78.

  Lungs, their liability to disease, 175-178.

  Lupus, 126.

  Malaria, 289-310.

  Measles, 243, 246, 248-252, 260-263.

  Medicines, repulsive, 17.

  Meningitis, 399, 400.
    _See also_ Cerebro-spinal meningitis.

  Mental influence in disease, 411-437.

  Metschnikoff, Elie, 214.

  Meyer, William, 105.

  Mind, its relation to the body, 390, 391, 411-437.

  Mosquitoes, and malaria, 297-307.

  Mouth-breathing, 103-119.

  Moxon, the pathologist, 187.

  Mumps, 252.

  Nails, the, in disease, 74, 75;
    pus-germs lurking under, 334, 336, 349.

  Nature, as a physician, 2, 3;
    not to be trusted too blindly, 7;
    coöperating with, 9.

  Nerves, affected in headache, 385, 386;
    old notions of, 387, 388;
    reality of, 389, 390;
    function of, 390;
    their diseases due to morbid changes in their tissues, 391, 392;
    affected by the bodily condition, 393-395;
    causes of disturbances in, 395-397;
    diseases that attack them directly, 397, 398;
    late effects of other diseases on, 398-401;
    nervousness and, 401-408;
    death-rate from diseases of, 409, 410.

  Nervousness, 403-408.

  Neurasthenia, 401, 402.

  Nocard, the veterinary pathologist, 157.

  Northrup, Dr. William, 196.

  Noses, narrow, 118, 119.

  Operations. _See_ Surgery.

  Opiates, 431, 432.

  Osler, Dr. William, 160, 282.

  Ovariotomy, 336.

  Pain, nature's command to halt, 13, 382;
    nature's automatic speed regulator, 383.

  Paresis, 399.

  Pimples, 38.

  Pituitary body, 119.

  Pneumonia, cause of, 84, 85, 88, 178-183, 185, 186;
    easily recognized, 174, 175;
    recent increase of, 184, 186;
    habits of the pneumococcus, 186-191;
    its relations to age and to other diseases, 192-194;
    symptoms of, 194, 195;
    treatment of, 195, 196;
    outlook as to, 196, 197.

  Poisons in the body, elimination of, 3-13;
    from fatigue, 373-376.

  Psychotherapy, 413.

  Pus, 331-336;
    germs of, 339-344, 346-349.

  Pyæmia, 346.

  Quinine, 293, 294.

  Repair of the body in the lower animals, 41, 42.

  Rheumatism, 311-330.

  Ross, Dr. Ronald, 247.

  Savages, nervousness among, 407, 408.

  Scarlet fever, 243, 247, 257-260.

  Sciatica, cure of a case of, 389, 390.

  Sclerosis, lateral, 399.

  Scrofula, 126.

  Seasickness, 379.

  Senn, Dr. Nicholas, 357.

  Septicæmia, 346.

  Sleeping porches, 96, 97.

  Smallpox, 125, 255.

  Smell, 111.

  Spitting, 142, 143.

  Staphylococcus, 339, 340, 343, 348.
    _See also_ Pus.

  Sticking-plaster, 343.

  Stomach, 274.

  Streptococcus, 339-341, 348. _See also_ Pus.

  Surgery, and blood-poisoning, 331-339.

  Syphilis congenital, 44;
    organism of, 255, 399;
    attacking the nervous system, 399.

  Tait, Lawson, 336.

  Taste, 111.

  Teeth, crowded, 114, 115.

  Tetanus, 344-346, 397, 398.

  Tonsillitis, 320, 323, 324.

  Tonsils, 107-109, 116-118.

  Tooth, wisdom, 36, 37.

  Tuberculosis, congenital, 45;
    seeming inheritance of, 46-50;
    diagnosis of, 68, 72;
    discovery of the bacterial nature of, 123-126;
    means of fighting, 127, 128;
    treatment of, 129-132;
    prevention of, 132, 135-139;
    universality of, 133, 134;
    prevention of transmission of, 140-145;
    in cattle and other animals, 146, 158;
    encouraging outlook as to, 159-166;
    civilization and, 166-173;
    cerebral complications from, 399;
    hopefulness in, 433.

  Tumor, Jensen's, 358, 362.

  Typhoid fever, 199-221.

  Typhus, 203, 204.

  Uric acid, 327, 328.

  Vestigia, 35-39, 268, 269.

  Virchow, Rudolf, 18.

  Vis medicatrix naturæ, 2.

  Voice, in diagnosis, 78.

  Voltaire, on doctors, 14.

  Vomiting, use of, 4, 5;
    from headache and seasickness, 378, 379;
    bile in, 379.

  Waters, mineral, 17.

  Whooping-cough, 244, 246, 249, 263-266.

  Williams, Dr. Leonard, 93.

  Williams, Dr. Roger, 364.

  Wound-fever, among soldiers, 347.

  Wounds, healing of, 40, 41;
    blood-poisoning in, 331-335, 341-344;
    treatment of, 342-344, 346.

  Wright, Dr., 221.

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End of Project Gutenberg's Preventable Diseases, by Woods Hutchinson