This clears the ground of a good many ancient misconceptions; for instance, that the chief cause of pneumonia is direct exposure to cold or a wetting, or the inhalation of raw, cold air. Few beliefs were more firmly fixed in the popular mind—and, for the matter of that, in the medical—up to fifteen or twenty years ago. It has found its way into literature; and the hero of the shipwreck in an icy gale or of weeks of wandering in the Frozen North, who must be offered up for artistic reasons as a sacrifice to the plot, invariably dies a victim of pneumonia, from his "frightful exposure," just as the victim of disappointed love dies of "a broken heart," or the man who sees the ambitions of years come crashing about his ears, or the woman who has lost all that makes life worth living, invariably develops "brain fever."

There is a physical basis for all of these standard catastrophes, but it is much slenderer than is usually supposed. For instance, almost every one can tell you how friends of theirs have "brought on congestion of the lungs," or pneumonia, by going without an overcoat on a winter day, or breaking through the ice when skating, or even by getting their feet wet and not changing their stockings; and this single dramatic instance has firmly convinced them that the chief cause of "lung fever" is a chill or a wetting. Yet when we come to tabulate long series of causes, rising into thousands, we find that the percentage in which even the patients themselves attribute the disease to exposure, or a chill, sinks to a surprisingly small amount. For instance, in the largest series collected with this point in mind, that of Musser and Norris, out of forty-two hundred cases only seventeen per cent gave a history of exposure and "catching cold"; and the smaller series range from ten to fifteen per cent. So that, even in the face of the returns, not more than one-fifth of all cases of pneumonia can reasonably be attributed to chill. And when we further remember that under this heading of exposure and "catching cold" are included many mere coincidences and the chilly sensations attending the beginning of those milder infections which we term "common colds," it is probable that even this small percentage could be reduced one-half. Indeed, most cautious investigators of the question have expressed themselves to this effect. This harmonizes with a number of obstinate facts which have long proved stumbling-blocks in the way of the theory of exposure as a cause of pneumonia. One of the classic ones was that, during Napoleon's frightful retreat from Moscow in the dead of winter, while his wretched soldiers died by thousands of frost-bite and starvation, exceedingly little pneumonia developed among them. Another was that, as we have already seen with colds, instead of being commoner and more frequent in the extreme Northern climate and on the borders of the Arctic Zone, pneumonia is almost unknown there. Of course, given the presence of the germ, prolonged exposure to cold may depress the vital powers sufficiently to permit an attack to develop.

Again, the ages at which pneumonia is both most common and most deadly, namely, under five and over sixty-five, are precisely those at which this feature of exposure to the weather plays the most insignificant part. Last and most conclusive of all, since definite statistics have begun to be kept upon a large scale, pneumonia has been found to be emphatically a disease of cities, instead of country districts. Even under the favorable conditions existing in the United States, for instance, the death-rate per hundred thousand living, according to the last census, was in the cities two hundred and thirty-three, and for the country districts one hundred and thirty-five,—in other words, nearly seventy per cent greater in city populations.

How, then, did the impression become so widely spread and so firmly rooted that pneumonia is chiefly due to exposure? Two things, I think, will explain most of this. One is, that the disease is most common in the winter-time, the other, that like all febrile diseases it most frequently begins with sensations of chilliness, varying all the way from a light shiver to a violent chill, or rigor. The savage, bone-freezing, teeth-rattling chill which ushers in an attack of pneumonia is one of the most striking characteristics of the disease, and occurs in twenty-five to fifty per cent of all cases.

Its chief occurrence in the winter-time is an equally well-known and undisputed fact, and it has been for centuries set down in medical works as one of the diseases chiefly due to changes in temperature, humidity, and directions of the wind. Years of research have been expended in order to trace the relations between the different factors in the weather and the occurrence of pneumonia, and volumes, yes, whole libraries, published, pointing out how each one of these factors, the temperature, humidity, direction of wind, barometric pressure, and electric tension, is in succession the principal cause of the spread of this plague. Many interesting coincidences were shown. But one thing always puzzled us, and that was, that the heaviest mortality usually occurred, not just at the beginning of winter, when the shock of the cold would be severest, nor even in the months of lowest temperature, like December or January, but in the late winter and the early spring. Throughout the greater part of the temperate zone the death-rate for pneumonia begins to rise in December, increases in January, goes higher still in February, reaching its climax in that month or in March. April is almost as bad, and the decline often doesn't fairly set in until May.

No better illustration could probably be given of the danger of drawing conclusions when you are not in possession of all the facts. One thing was entirely overlooked in all this speculation until about twenty years ago,—that pneumonia was due not simply to the depressing effects of cold, but to a specific germ, the pneumococcus of Fraenkel. This threw an entirely new light upon our elaborate weather-causation theories. And while these still hold the field by weight of authority and that mental inertia which we term conservatism, yet the more thoughtful physicians and pathologists are now coming to regard these factors as chiefly important according to the extent to which we are crowded together in often badly lighted and ill-ventilated houses and rooms, with the windows and doors shut to save fuel, thus affording a magnificent hothouse hatching-ground for such germs as may be present, and ideal facilities for their communication from one victim to another. At the same time, by this crowding and the cutting off of life and exercise in the open air which accompanies it, the resisting power of our bodies is lowered. And when these two processes have had an opportunity of progressing side by side for from two to three months; when, in other words, the soil has been carefully prepared, the seed sown, and the moist heat applied as in a forcing-house, then we suddenly reap the harvest. In other words, the heavy crop of pneumonia in January, February, and March is the logical result of the seed-sowing and forcing of the preceding two or three months.

The warmth of summer is even more depressing in its immediate effects than the cold of winter, but the heat carries with it one blessing, in that it drives us, willy-nilly, into the open air, day and night. And on looking at statistics we find precisely what might have been expected on this theory, that the death-rate for pneumonia is lowest in July and August.

It might be said in passing that, in spite of our vivid dread of sunstroke, of cholera, and of pestilence in hot weather, the hot months of the year in temperate climates are invariably the months of fewest diseases and fewest deaths. Our extraordinary dread of the summer heat has but slender rational physical basis. It may be but a subconscious after-vibration in our brain cells from the simoons, the choleras, and the pestilences of our tropical origin as a race. Open air, whether hot, cold, wet, dry, windy, or still, is our best friend, and house air our deadliest enemy.

If this view be well founded, then the advance of modern civilization would tend to furnish a more and more favorable soil for the spread of this disease. This, unfortunately, is about the conclusion to which we are being most unwillingly driven. Almost every other known infectious disease is diminishing, both in frequency and in fatality, under civilization. Pneumonia alone defies our onslaughts. In fact, if statistics are to be taken at their surface-value, we are facing the appalling situation of an apparently marked increase both in its prevalence and in its mortality. For a number of years past, ever since, in fact, accurate statistics began to be kept, pneumonia has been listed as the second heaviest cause of death, its only superior being tuberculosis.

About ten years ago it began to be noticed that the second competitor in the race of death was overtaking its leader, and this ghastly rivalry continued until about three years ago pneumonia forged ahead. In some great American cities it now occupies the bad eminence of the most fatal single disease on the death-lists.

The situation is, however, far from being as serious and alarming as it might appear, simply from this bald statement of statistics. First of all, because the forging ahead of pneumonia has been due in greater degree to the falling behind of tuberculosis than to any actual advance on its part. The death-rate of tuberculosis within the last thirty years has diminished between thirty and forty per cent; and pneumonia at its worst has never yet equaled the old fatality of tuberculosis. Furthermore, all who have carefully studied the subject are convinced that much of this apparent increase is due to more accurate and careful diagnosis. Up to ten years or so ago it was generally believed that pneumonia was rare in young children. Now, however, that we make the diagnosis with a microscope, we discover that a large percentage of the cases of capillary bronchitis, broncho-pneumonia, and acute congestion of the lung in children are due to the presence of the pneumococcus. Similarly, at the other end of the line, deaths that were put down to bronchitis, asthma, heart failure, yes, even to old age, have now been shown on bacteriological examination to be due to this ubiquitous imp of malevolence; so that, on the whole, all that we are probably justified in saying is that pneumonia is not decreasing under civilization. This is not to be wondered at, inasmuch as the inevitable crowding and congestion which accompanies civilization, especially in its derivative sense of "citification," tends to foster it in every way, both by multiplying the opportunities for infection and lowering the resisting power of the crowded masses.

Moreover, it was only in the last ten years, yes, within the last five years, that we fairly grasped the real method and nature of the spread of the disease, and recognized the means that must be adopted against it. And as all of these factors are matters which are not only absolutely within our own control, but are included in that programme of general betterment of human comfort and vigor to which the truest intelligence and philanthropy of the nation are now being directed, the outlook for the future, instead of being gloomy, is distinctly encouraging.

Our chief difficulty in discovering the cause of pneumonia lay in the swarm of applicants for the honor. Almost every self-respecting bacteriologist seemed to think it his duty to discover at least one, and the abundance and variety of germs constantly or accidentally present in the human saliva made it so difficult positively to isolate the real criminal that, although it was identified and described as long ago as 1884 by Fraenkel, the validity of its claim was not generally recognized and established until nearly ten years later.

It is a tiny, inoffensive-looking little organism, of an oval or lance-head shape, which, after masquerading under as many aliases as a confidence man, has finally come to be called the pneumococcus, for short, or "lung germ." Though by those who are more precise it is still known as the Diplococcus pneumoniae or Diplococcus lanceolatus, from its faculty of usually appearing in pairs, and from its lance-like shape. Its conduct abounds in "ways that are dark and tricks that are vain," whose elucidation throws a flood of light upon a number of interesting problems in the spread of disease.

First of all, it literally fulfills the prognostic of Scripture, that "a man's foes shall be they of his own household," for its chosen abiding place and normal habitat is no less intimate a place than the human mouth. Outside of this warm and sheltering fold it perishes quickly, as cold, sunlight, and dryness are alike fatal to it.

We could hardly believe the evidence of our senses when studies of the saliva of perfectly healthy individuals showed this deadly little bacillus to be present in considerable numbers in from fifteen to forty-five per cent of the cases examined. Why, then, does not every one develop pneumonia? The answer to this strikes the keynote of our modern knowledge of infectious disease, namely, that while an invading germ is necessary, a certain breaking down of the body defenses and a lowering of the vital resistance are equally necessary. These invaders lie in wait at the very gates of the citadel, below the muzzles of our guns, as it were, waiting for some slackening of discipline or of watchfulness to rush in and put the fortress to sack. Nowhere is this more strikingly true than in pneumonia. It is emphatically a disease where, in the language of the brilliant pathologist-philosopher Moxon, "While it is most important to know what kind of a disease the patient has got, it is even more important to know what kind of a patient the disease has got."

The death-rate in pneumonia is an almost mathematically accurate deduction from the age, vigor, and nutrition of the patient attacked. No other disease has such a brutal and inveterate habit of killing the weaklings. The half-stifled baby in the tenement, the underfed, overworked laboring man, the old man with rigid arteries and stiffening muscles or waning life vigor, the chronic sufferer from malnutrition, alcoholism, Bright's disease, heart disease—these are its chosen victims.

Another interesting feature about the pneumococcus is its vitality outside of the body. If the saliva in which it is contained be kept moist, and not exposed to the direct sunlight and in a fairly warm place, it may survive as long as two weeks. If dried, but kept in the dark, it will survive four hours. If exposed to sunlight, or even diffuse daylight, it dies within an hour. In other words, under the conditions of dampness and darkness which often prevail in crowded tenements it may remain alive and malignant for weeks; in decently lighted and ventilated rooms, less than two hours. This explains why, in private practice and under civilized conditions, epidemics of this admittedly infectious disease are rare; while in jails, overcrowded barracks, prison ships, and winter camps of armies in the field they are by no means uncommon. This is vividly supported by the fact brought out in our later investigations of the sputum of slum-dwellers, carried out by city boards of health, that the percentage of individuals harboring the pneumococcus steadily increases all through the winter months, from ten per cent in December to forty-five, fifty, and even sixty per cent in February and March. The old proverb, "When want comes in at the door, Love flies out at the window," might be revised to read, "When sunlight comes in at the window the pneumococcus flies 'up the flue.'"

Authorities are still divided as to the meaning and even the precise frequency of the occurrence of the pneumococcus in the healthy human mouth. Some hold that its presence is due to recent infection which has either been unable to gain entrance to the system or is preparing its attack; others, that it is a survival from some previous mild attack of the disease, and the body tissues having acquired immunity against it, it remains in them as a harmless parasite, as is now well known to be the case with the germs of several of our infectious diseases—for instance, typhoid—for months and even years afterward. Others hold the highly suggestive view that it is a normal inhabitant of the healthy mouth, which can become injurious to the body, or pathogenic, only under certain depressed or disturbed conditions of the latter. In defense of this last it may be pointed out that dental bacteriologists have now already isolated and described some thirty different forms of organisms which inhabit the mouth and teeth; and the pneumococcus may well be one of these. Further, that a number of our most dangerous disease germs, like the typhoid bacillus, the bacillus of tuberculosis, and the bacillus of diphtheria, have almost perfect "doubles," law-abiding relatives, so to speak, among the germs that normally inhabit our throats, our intestines, or our immediate surroundings. The ultimate foundation question of the science of bacteriology is, How did the disease germs become disease germs? But the question is still unanswered.

However, fortunately, here, as in other human affairs, imperfect as our knowledge is, it is sufficient to serve as a guide for practical conduct. Widely present as the pneumococcus is, we know well that it is powerless for harm except in unhealthful surroundings. There is another interesting feature of its life history which is of practical importance, and that is, like many other bacilli it is increased in virulence and infectiousness by passing through the body of a patient. Flushed with victory over a weakened subject, it acquires courage to attack a stronger. This is the reason why, in those comparatively infrequent instances in which pneumonia runs through a family, it is the strongest and most vigorous members of the family who are the last to be attacked. It also explains one of the paradoxes of this disease, that, while emphatically a disease of overcrowding and foul air, and attacking chiefly weakened individuals, it is a veritable scourge of camps, whether mining or military. When once three or four cases of pneumonia have occurred in a mining camp, even though this consist almost exclusively of vigorous men, most of them in the prime of life, it acquires a virulence like that of a pestilence, so that, while ordinarily not more than fifteen to twenty per cent of those attacked die, death-rates of forty, fifty, and even seventy per cent are by no means uncommon in mining camps. The fury and swiftness of this "miners' pneumonia" is equally incredible. Strong, vigorous men are taken with a chill while working in their sluicing ditches, are delirious before night, and die within forty-eight hours. So widely known are these facts, and so dreaded is the disease throughout the Far West and in mountain regions generally, that there is a widespread belief that pneumonia at high altitudes is particularly deadly.

I had occasion to interest myself in this question some years ago, and by writing to colleagues practicing at high elevations and collecting reports from the literature, especially of the surgeons of army posts in mountain regions, was somewhat surprised to find that the mortality of all cases occurring above five thousand feet elevation was almost identical with that of a similar class of the population at sea-level. It is only when a sufficient number of cases occur in succession to raise the virulence of the pneumococcus in this curious manner that an epidemic with high fatality develops.

That this increase in virulence in the organism does occur was clearly demonstrated by a bacteriologist friend of mine, who succeeded in securing some of the sputum from a fatal case in the famous Tonopah epidemic of some years ago, an epidemic so fatal that it was locally known as the "Black Death." Upon injecting cultures from this sputum into guinea-pigs, the latter died in one-quarter of the time that it usually took them to succumb to a similar dose of an ordinary culture of the pneumococcus.

It is therefore evident that just as "no chain is stronger than its weakest link," so in the broad sense no community is stronger than its weakest group of individuals, and pneumonia, like other epidemics, may be well described as the vengeance which the "submerged tenth" may wreak from time to time upon their more fortunate brethren.

Now that we know that under decent and civilized conditions of light and ventilation the pneumococcus will live but an hour to an hour and a half, this reduces the risk of direct infection under these conditions to a minimum. It is obvious that the principal factors in the control of the disease are those which tend to build up the vigor and resisting power of all possible victims. The more broadly we study the disease the more clearly do the data point in this direction.

First of all, is the vivid and striking contrast between hospital statistics and those gathered from private practice. While many individuals of a fair wage-earner's income and good bodily vigor are treated in our hospitals, yet the vast majority of hospital patients are technically known as the "hospital classes," apt to be both underfed, overworked, and overcrowded. On the other hand, while a great many both of the very poor and even of the destitute are treated in private practice, yet the majority of such cases who feel "able to afford a doctor," as they say, are among the comparatively vigorous, well-fed, and well-housed section of the community. And the difference between the death-rate of the two classes in pneumonia is most significant. In private practice, while epidemics differ in virulence, the rate ranges all the way from five per cent to fifteen per cent, the average being not much in excess of ten per cent, occasionally falling as low as three per cent. In the hospital reports on the contrary the death-rate begins at twenty per cent and climbs to thirty, forty, and forty-five per cent. It is only fair to say, of course, that hospital statistics probably include a larger percentage of more serious cases, the milder ones being taken care of at home, or not presenting themselves for treatment at all. But even when this allowance has been made, the contrast is convincing.

A similar influence is exercised by age. Although pneumonia is common at all ages, its heaviest death-rate falls at the two extremes, under six years of age and over sixty, with a strong preponderance in the latter. Under five years of age, the mortality may reach twenty to thirty per cent; from five to twenty-five, not more than four to five per cent; from twenty-five to thirty-five, from fifteen to twenty per cent; and so on, increasing gradually with every decade until by sixty years of age the mortality has reached fifty per cent, and from sixty to seventy-five may be expressed in terms of the age of the patient. One consoling feature, however, about it is that its mortality is lowest in the ages at which it is most frequent, namely, from ten to thirty-five years of age. And its frequency diminishes even more rapidly than its fatality increases in later years. So that while it is much more serious in a middle-aged man, he is less liable to develop it than a younger one. Where the mortality from pneumonia is highest, is in the most densely populated wards, especially among negroes and foreigners of the hospital class, in individuals who are victims of chronic alcoholism, and also among those who are for long periods insufficiently nourished. Lastly, it is only within comparatively recent years that we have come clearly to recognize the large role which pneumonia plays in giving the finishing stroke to chronic diseases and degenerative processes. It is, for instance, one of the commonest actual causes of death in Bright's disease, in diabetes, in lingering forms of tuberculosis, and in heart disease; and last of all, in that progressive process of normal degeneration and decay which we term "Old Age." It is one of the most frequent and fatal of what Flexner described a decade ago as "terminal infections." Very few human beings die by a gradual process of decay, still less go to pieces all at once, like the immortal "One-Hoss Shay." Just as soon as the process has progressed far enough to lower the resisting power below a certain level, some acute infection steps in and mercifully ends the scene. This is peculiarly true of pneumonia in old age.

To the medical profession to "die of old age" is practically equivalent to dying of pneumonia. The disease is so mild in its symptoms and so rapid in its course that it often utterly escapes recognition as such.

The old man complains of a little pain in his chest, a failure of appetite, a sense of weakness and dizziness. He takes to his bed, within forty-eight hours he becomes unconscious, and within twenty-four more he is peacefully breathing his last. After death, two-thirds of the lung will be found consolidated. So mild and rapid and painless is the process that one physician-philosopher actually described pneumonia as "the friend of old age."

When once the disease has obtained a foothold in the body its course, like one of Napoleon's campaigns, is short, sharp, and decisive. Beginning typically with a vigorous chill, sometimes so suddenly as to wake the patient out of a sound sleep, followed by a stabbing pain in the side, cough, high fever, rapid respiration, the sputum rusty or orange-colored from leakage of blood from the congested lung, within forty-eight hours the attacked area of the lung has become congested; in forty-eight more, almost solidified by the thick, sticky exudate poured out from the blood-vessels, which coagulates and clots in the air cells. So complete is this solidification that sections of the attacked lung, instead of floating in water as normal lung-tissue will, sink promptly. The severe pain usually subsides soon, but the fever, rapid respiration, flushed face, with or without delirium, will continue for from three to seven or eight days. Then, as suddenly as the initial attack, comes a plunge down of the temperature to normal. Pain and restlessness disappear, the respiration drops from thirty-five or forty to fifteen or twenty per minute, and the disease has practically ended by "crisis." Naturally, after such a furious onslaught, the patient is apt to be greatly weakened. He may have lost twenty or thirty pounds in the week of the fever, and from one to three weeks more in bed may be necessary for him to regain his strength. But the chief risk and danger are usually over within a week or ten days at the outside.

Violent and serious as are the changes in the lung, it is very seldom that death comes by interference with the breathing space. In fact, while regarded as a lung disease, we are now coming to recognize that the actual cause of death in fatal cases is the overwhelming of the heart by the toxins or poisons poured into the circulation from the affected lung. The mode of treatment is, therefore, to support the strength of the patient in every way, and measures directed to the affected lung are assuming less and less importance in our arsenal of remedies. Our attitude is now very similar to that in typhoid, to support the strength of the patient by judicious and liberal feeding, to reduce the fever and tone up his blood-vessels by cool sponging, packing, and even bathing; to relieve his pain by the mildest possible doses of sedatives, knowing that the disease is self-limited, and that in patients in comfortable surroundings and fair nutrition from eighty to ninety per cent will throw off the attack within a week. So completely have we abandoned all idea of medicating or protecting the lung as such, that in place of overheated rooms, loaded with vapor by means of a steam kettle, for its supposed soothing effect upon the inflamed lung, we now throw the windows wide open. And some of our more enthusiastic clinicians of wide experience are actually introducing the open-air cure, which has worked such wonders in tuberculosis, in the treatment of pneumonia. In more than one of our New York hospitals now, particularly those devoted to the care of children, following the brilliant example of Dr. William Northrup, wards are established for pneumonia cases out on the roof of the hospital, even when the snow is banked up on either side, and the covering is a canvas tent. Nurses, physicians, and ward attendants are clothed in fur coats and gloves, the patients are kept muffled up to the ears, with only the face exposed; but instead of perishing from exposure, little, gasping, struggling tots, whose cases were regarded as practically hopeless in the wards below, often fall into the sleep that is the turning point toward recovery within a few hours after being placed in this winter roof-garden.

In short, our motto may be said to be, "Take care of the patient, and the disease will take care of itself."

Though pneumonia is one of our most serious and most fatal of diseases, yet it is one over whose cause, spread, and cure we are obtaining greater and greater control every day, and which certainly should, within the next decade, yield to our attack, as tuberculosis and typhoid are already beginning to do.



CHAPTER IX

THE NATURAL HISTORY OF TYPHOID FEVER

Why should not a disease have a natural history, as well as an individual? At first sight, this might appear like a reversion to the old, crude theory of disease as a demonic obsession, or invasion by an evil spirit, of which traces still remain in such expressions as, "She was seized with a convulsion," "He was strong enough to throw off the illness," "He was attacked by a fever," etc. But apart entirely from such conceptions, which were perfectly natural in the infancy of the race, while clearly recognizing that disease is simply a perverted state of nutrition or well-being in the body of the patient, a disturbance of balance, so to say, yet it is equally true that it has a birth, an ancestry, a life-course, and a natural termination, or death.

This recognition of the natural causation and development of disease has been one of the greatest triumphs, not merely of pathology, but of intelligence and rationalism. It has done more to diminish that dread of the unknown which hangs like a black pall of terror over the mind of the savage and the semi-civilized mind than any other one advance. It contributes enormously to our courage, our hopefulness, and our power of protection in more ways than one: first of all, by revealing to us the external cause of disease, usually some careless, dirty, or bad habit on the part of an individual or of the community, and thus enabling us to limit its spread and even exterminate it; secondly, by assuring us that nearly all diseases, excepting a few of the most obstinate and serious, have not only a definite beginning, but a definite end, are, in fact, if left to themselves, self-limited, either by the exhaustion and loss of virulence of their cause, or by the resisting power of the body.

All infectious diseases, and many others, tend to run a definite course of so many days, or so many weeks, within certain limits, and at least ninety per cent of them tend to terminate in recovery. It is a most serious and fatal disease which has a death-rate of more than twenty per cent. Typhoid, pneumonia, diphtheria, and yellow fever all fall below this, smallpox barely reaches it, and only the bubonic plague, cholera, and lockjaw rise habitually above it. The recognition of this fact has enormously increased the efficiency of the medical profession in dealing with disease, by putting us on the track of imitating the methods which the body itself uses for destroying, or checking the spread of, invading germs and leading us to trust nature and try to work with her instead of against her. Our antitoxins and anti-serums, which are our brightest hope in therapeutics at present, are simply antidotes which are formed in the blood of some healthy, vigorous animal against the bacillus whose virulence we wish to neutralize, such as that of diphtheria or septicemia.

Diphtheria antitoxin, for instance, the first and best known triumph of the new medicine, is the antidotal substance formed in the blood of a horse in response to a succession of increasing doses of the bacilli of diphtheria. Similar antidotal substances are formed in the blood in all other non-fatal cases of infectious diseases, such as typhoid, pneumonia, blood-poisoning, etc.; and the point at which they have accumulated in sufficient amounts to neutralize the poison of the invading germs, forms the crisis, or "turn" of the disease. So that when we speak of a disease "running its course," we mean continuing for such length of time as the body needs to produce anti-bodies in sufficient amounts to check it.

The principal obstacle to the securing of antitoxins like that of diphtheria for all our infectious diseases is, that their germs form their poison so slowly that it is difficult to collect it in sufficient amounts to produce a strong concentrated antitoxin in the animal into which it is injected. But the overcoming of this difficulty is probably only a question of time.

Obviously, if infectious disease be, as we say, "self-limited," that is to say, if the body will defeat the invaders with its own weapons, on an average in nine cases out of ten, our wisest course, as physicians, is to back up the body in its fight. This we now do in every possible way, by careful feeding, by rest, by bathing, by an abundance of pure water and fresh air, with the gratifying result that we have already reduced the death-rate in most fevers, even such as we have no antitoxin against, or may not even have discovered the causal germ of, to one-half and even three-fourths of their former fatality. The recognition of the fact that disease has a natural history, a birth, a term of natural life and a death, has already turned a hopeless fight in the dark into a victorious campaign in broad daylight. Huxley's pessimistic saying that typhoid was like a fight in the dark between the disease and the patient, and the doctor like a man with a club striking into the melee, sometimes hitting the disease and sometimes the patient, is no longer true since the birth of bacteriology.

Nowhere can the natural history of disease be more clearly seen or more advantageously studied than in the case of typhoid fever.

The cause of typhoid is simplicity itself, merely drinking the excreta of some one else, "eating dirt," in the popular phrase; simple, but of a deadly effectiveness, and disgracefully common. The demon may be exorcised by an incantation of one sentence: Keep human excreta out of the drinking water. This sounds simple, but it is n't. Eternal vigilance is the price of health as well as of liberty.

We can, however, make our pedigree of typhoid a little more precise. It is not merely dirt of human origin which is injurious, but dirt of a particular type, namely, discharges from a previous case of the disease. Just as in the fight against malaria we have not the enormous problem of the extermination of all varieties of mosquito, but only of one particular genus, and only the infected specimens of that, so in typhoid, the contamination of water or food which we have to guard against is that from previous cases. From one point of view, this leaves the problem as wide as ever, for, obviously, the only way to insure against poisoning of water by typhoid discharges is to shut out absolutely all sewage contamination. On the other hand, it is of immense advantage in this regard,—it enables us to fight the enemy at both ends of the line, to turn his flank as well as crush his centre.

While we are protecting our water-supplies against sewage, we can, in the meantime, render that sewage comparatively harmless by thoroughly disinfecting and sterilizing all discharges from every known case of the disease. A similar method is used in the fight against yellow fever and malaria. Not only are the breeding places of the two mosquito criminals broken up, but each known case of the disease is carefully screened, so as to prevent the insects from becoming infected, and thus able to transmit the disease to other human victims.

It cannot be too emphatically insisted upon that every case of typhoid, like every case of yellow fever and of malaria, comes from a previous case. It is neither healthy nor exhilarating to drink a clear solution of sewage, no matter how dilute; but, as a matter of fact, it is astonishing how long communities may drink sewage-laden water with comparative impunity, so long as the sewage contains no typhoid discharges. One case of typhoid fever imported into a watershed will set a city in a blaze.

The malevolent Deus in the sewage machina is, of course, a germ—the Bacillus typhosus of Eberth. The astonishing recentness of much of our most important knowledge is nowhere better illustrated than in the case of typhoid. Although there had been vague descriptions of a fatal fever, slow and lingering in its character and accompanied by prolonged stupor and delirium, which was associated with camps and dirty cities and famines, from as far back as the age of Caesar, the first description clear enough to be recognizable was that of Willis, of an epidemic during the English civil war in 1643, both Royalist and Roundhead armies being seriously crippled by it. Since that time a smouldering, slowly spreading fever has been pretty constantly associated with armies in camps, besieged cities, filthy jails, and famines, to which accordingly have been given the names, familiar in historical literature, of "famine fever," "jail fever," and "military fever."

So slowly, however, did accurate knowledge come, that it was actually not until 1837 that it was clearly and definitely recognized that this famine fever was, like Mrs. Malaprop's Cerberus, "two gentlemen at once," one form of it being typhus or "spotted fever," which has now become almost extinct in civilized communities; the other, the milder, but more persistent form, which, like the poor, we have always with us, called, from its resemblance to the former, "typhoid" (typhus-like).

Typhus was a far more virulent, rapid, and fatal fever than its twin survivor, though as to the relations between the two diseases, if any, we are quite in the dark, as the former practically disappeared before the days of bacteriology. The fact of its disappearance is both significant and interesting, in that it was unquestionably due to the ranker and viler forms of both municipal and individual filthiness and unsanitariness, which even our moderate progress in civilization has now abolished. There can be no question that, with a step higher in the scale of cleanliness, and further quickening of the biologic conscience, typhoid will also disappear.

Typhus, the bubonic plague, the sweating sickness, were alike plagues and products of times when table-scraps were thrown on the dining-room floor and covered daily with fresh rushes for a week at a stretch, and fertilizer accumulated in a living-room as now in a modern stable. Clothing was put on for the season, shirts were unknown, and strong perfumes took the place of a bath. Michelet's famous characterization of the Middle Ages in one phrase as Un mille ans sans bain (a thousand years without a bath) was painfully accurate.

Doubtless certain habits of our own to-day will be regarded with equal disgust by our descendants. Typhus, by the way, may possibly be remembered by the dramatic "Black Assize" of Oxford, in 1577, in which not merely the wretched prisoners in the jail, but the jurors, the lawyers, the judges, and every official of the court were attacked, and many of them died.

It was only in 1856 that the method of transmission of the disease was clearly recognized, and in 1880 that the bacillus was discovered and identified by the bacteriologist Eberth, whose name it bears, so that it is only within the last thirty years that real weapons have been put into our hands with which to begin a fight of extermination against the disease.

What is the habitat of our organism, and is it increasing its spread? Its habitat is the entire civilized world, and it goes wherever civilization goes. In this sense its spread is increasing, but, in every other, we have good ground for believing that it is on the wane. Positive assurance, either one way or the other, is, of course, impossible, simply for the reason that the disease was not recognized until such a short time ago that no statistics of any real value for comparison are available; and, secondly, because even to-day, on account of its insidious character and the astonishing variety of its forms, and degrees of mildness and virulence, a considerable percentage of cases are yet unrecognized and unreported.

It might be mentioned in passing that this statement applies to the alleged increase of nearly all diseases which are popularly believed to be modern inventions, like appendicitis, insanity, and cancer. We have no statistics more than thirty years old which are of real value for purposes of comparison.

However, when it comes to the number of deaths from the disease, there is a striking and gratifying diminution for twenty years past, which is increasing in ratio instead of diminishing. That we are really getting control of typhoid is shown by the, at first sight, singular and decidedly unexpected fact that it is no longer a disease of cities, but of the country. The death-rate per thousand living in the cities of the United States is lower than in the rural districts. For instance, the mortality in the State of Maryland, outside of Baltimore, is two and one-half times as great as that in the city itself. Our period of greatest outbreak in the large cities is now the month of September, when city dwellers have just returned from their vacations in the pure and healthful country, bringing the bacilli in their systems.

The moral is obvious. Great cities are developing some sort of a sanitary conscience. Farmers and country districts have as yet little or none. Bad as our city water often is, and defective as our systems of sewage, they cannot for a moment compare in deadliness with that most unheavenly pair of twins, the shallow well and the vault privy. A more ingenious combination for the dissemination of typhoid than this precious couple could hardly have been devised. The innocent householder sallies forth, and at an appropriate distance from his cot he digs two holes, one about thirty feet deep, the other about four. Into the shallower one he throws his excreta, while upon the surface of the ground he flings abroad his household waste from the back stoop. The gentle rain from heaven washes these various products down into the soil and percolates gradually into the deeper hole. When the interesting solution has accumulated to a sufficient depth, it is drawn up by the old oaken bucket or modern pump, and drunk. Is it any wonder that in this progressive and highly civilized country three hundred and fifty thousand cases of typhoid occur every year, with a death penalty of ten per cent? Counting half of these as workers, and the period of illness as two months, which would be very moderate estimates, gives a loss of productive working time equivalent to thirty thousand years. Talk of "cheap as dirt"! It is the most expensive thing there is.

Typhoid still abundantly earns its old name of "military fever," and its sinister victories in war are even more renowned than its daily triumphs in peace. Strange as it may seem, the deadliest enemies of the soldier are not bullets but bacilli, and sewage is mightier than the sword. For instance, in the Franco-Prussian War, typhoid alone caused sixty per cent of all the deaths. In the Boer War it caused nearly six thousand deaths as compared with seven thousand five hundred from wounds in battle, while other diseases caused five thousand more. In the majority of modern campaigns, from two-thirds to five-sixths of all deaths are due to disease and not to battle. It may be that we sanitarians will achieve the ends of the peace congresses by an unexpected route, and make war a healthful and comparatively harmless form of national gymnastics. Its battle-mortality rate, for the number engaged, is not so very far above football now!

Given the bacillus, how does it get into the human system? Here the evidence is so abundant and overwhelming that we may content ourselves with bald statements of fact. The three great routes of this pestilence are water, milk, and flies. Of the three, the first is far the most common and important. While only a rough statement is possible, probably eighty-five per cent of all cases from water, five per cent from milk, five per cent through flies, and five per cent through other channels, would fairly represent the percentage.

That it is conveyed through water is as certain as that the sun rises and sets. The only embarrassment in proving it lies in selecting from the swarm of instances. There is the classic case of the Swiss villages on opposite sides of the same mountain chain, the second of which drew its water-supply from a spring that came through the mountain from a brooklet running by the first village. Typhoid fever broke out in the first village, and twenty days later it appeared in the second village, twenty miles away on the other side of the mountain. Colored particles thrown into the brook on one side promptly appeared in the spring upon the other. Then there was the gruesome modern instance of Plymouth, Pennsylvania, in 1885. A single case of imported typhoid occurring on the watershed of a reservoir was followed, thirty days later, by an epidemic of eleven hundred cases in a population of eight thousand.

An equally vivid instance came under my own observation. A school and a penitentiary drew their water-supply from the same power-flume, carrying a superb volume of purest water from a mountain stream. Early in the autumn a single case of typhoid appeared in a small town near the head of the flume. The discharges were thrown into the swiftly running water. Two weeks later an epidemic of typhoid broke out in the school, and three weeks later in the penitentiary. An unexpected freak, however, was the appearance of fifteen or twenty cases in another state institution farther down on the same stream, which did not draw its water-supply from the flume, but from deep wells of tested purity. This was a puzzle, until it was found that, owing to a fall in the wells, the water from the flume had been used for sprinkling and washing purposes in the institution, being allowed to run through the water-pipes only at night, while the well-water was used in the daytime. This was enough to contaminate the pipes, and a small epidemic began, which promptly stopped as soon as the cause was suspected and the flume-water no longer used.

This last instance is peculiarly interesting, as illustrating how typhoid infection gets into milk, the second—though at a long interval—most frequent means of its spread. It does not come from the cow, for, fortunately, none of the domestic animals, with the possible exception of the cat, is subject to typhoid. Nor is it possible that cattle, drinking foul and even infected water, can transmit the bacillus in their milk. That superstition was exploded long ago. Every epidemic of typhoid spread by milk—and there are scores of them now on record—can be traced to the handling of the milk by persons suffering from mild forms of typhoid, or engaged in waiting upon members of the family who are ill of the disease, or the dilution of milk with infected water, or even, almost incredible as it may seem, to such slight contamination as washing the cans with infected water.

Health officers now watch like hawks for the appearance of any case of typhoid among or in the families of dairymen. The New York City Board of Health, for instance, requires the weekly filing of a certificate from the family physician of all dairymen that no such cases exist. And the more intelligent dairymen keep a vigilant eye upon any appearance of illness accompanied by fever among their employees, some that I have known even keeping a fever thermometer in the barn for the purpose of testing every suspicious case. How effective such precautions can be made may be illustrated by the fact that, in the past five years, there has not been a single epidemic of typhoid traceable to milk in Greater New York, even with its inadequate corps of ten inspectors, and the six states they have to cover. The moment a single case of typhoid appears, the dairy or milkman supplying that customer is given a most rigid special inspection, and, if any source of infection can be discovered, the milk is shut out of New York City until the department is satisfied that all danger has been removed. One or two lessons of this sort are enough for a whole county of dairymen. The danger of transmission of typhoid through milk has been enormously exaggerated, and, as in the case of all other milk-borne diseases, is entirely due to filthy handling, and may be prevented by intelligent sanitary policing. Even with our present exceedingly imperfect systems, probably not more than between five and ten per cent of typhoid is transmitted in this way; and, if the water-supply were kept clean, this would practically disappear.

Typhoid may not only be transmitted from the earth beneath and the water under the earth, but also from the heavens above, through the medium of flies and dust. The first method is bulking larger every day, especially in country districts and in camps. The modus operandi is simplicity itself. The fly lives and moves and has its being in dirt. It breeds in dirt and it feeds on food, and, as it never wipes its feet, the interesting results can be imagined. Just to dispel any possible doubt, plates of gelatine have been exposed where flies could walk on them, then placed in an incubator, and within forty-eight hours there was a clearly recorded track of the footprints of the flies written in clumps of bacilli sown by their filthy feet. More definitely, flies have been caught in the houses of typhoid patients, put under the microscope, and their feet, stomachs, and specks found swarming with typhoid bacilli. A single flyspeck may contain three thousand.

Fortunately, we have a simple and effective remedy. We cannot disinfect the fly nor make him wipe his feet, but we can exterminate him utterly! This sounds difficult, but it isn't. Like the mosquito, the fly can only breed in one particular kind of place, and that place is a heap of dirt, preferably horse manure, but, at a pinch, dust-bins, garbage-cans, sweepings under porches or behind furniture, vaults,—anywhere that dirt is allowed to remain undisturbed for more than a week at a stretch. Abolish, screen, or poison these dirt accumulations, and flies will disappear, and with them not merely risks from typhoid, but half a dozen other diseases, as well as all sorts of filth and much discomfort and inconvenience. It was largely through flies that the disgraceful epidemic of typhoid, which ravaged our camps on our own soil during the Spanish-American War and killed many times more than fell by Spanish bullets, was spread.

It is also believed that typhoid bacilli may be carried in the infected dust of streets and camps. Here again we are dealing with a dangerous public enemy to both health and comfort, which can and ought to be abated by cleanliness, oilings, and sprinklings. Typhoid bacilli are also occasionally carried by shellfish, especially oysters, on account of the interesting modern custom of planting them in bays and harbors near the mouths of sewers to fatten them. The cheerful motto of the oysterman is, "The muddier the water the fatter the oyster." And nowhere do the bivalves plump up more quickly than near the mouth of a sewer.

The last method of transmission is by direct contact with the sick. This is a relatively rare means of spread, so much so that it is generally stated that typhoid is not contagious; but it is a real source of danger and one against which precautions should by all means be taken. The only method is, of course, by the soiling of the hands of the nurse or other attendant, and then eating or touching food, or putting the fingers into the mouth before thoroughly cleansing. If the hands be washed with a strong antiseptic solution after waiting upon the patient, and the cheerful habit sometimes indulged in of putting fruit or other delicacies into the sick-room for a day or so, in the hope that they may tempt the appetite of the patient, and then taking them out and letting the children eat them as a treat, be abolished, and the nurse be not allowed to officiate in the kitchen, risk from this source will be done away with.

When the bacillus has been introduced into the stomach through food or drink, it rapidly proceeds to diffuse itself throughout the tissues of the body. Because the most striking symptoms of the disease are diarrh[oe]a, abdominal distention, and pain, and the most striking lesions after death ulcers in the small intestine, it was supposed that the process was confined to the abdominal organs. This is now known to be an error, as cultures and examinations made from the blood and various parts of the body have shown the presence of the typhoid bacillus in almost every organ and tissue. This process of scattering, or invasion of the body, takes from three to ten days to accomplish; and the first sign of trouble is usually a feeling of depression, with headache, and perhaps slight nausea, before any characteristic bowel symptoms begin to show themselves.

The general invasion of the system throws an interesting sidelight upon the subject of premonitions. There are several well authenticated cases on record where individuals just before coming down with typhoid have been strangely impressed with a sense of impending death, and have even gone so far as to make their wills and set their affairs in order. Because these strong impressions appeared before any clearly marked intestinal symptoms of the disease, they have been put down in popular literature as instances of the "second sight," or "sixth sense," which popular superstition believes many of us to possess under certain circumstances. Now, however, we know that the tissues of that individual were already swarming with bacilli, and his fear of impending death was simply the effect of his toxin-laden blood upon his brain centres. In other words, it was prophecy after the fact, like nearly all prophecies that happen to come true; and the "premonition" was an early symptom of the disease itself.

As it is, of course, difficult to fix the precise drink of water or mouthful of food in which the infection was conveyed, we were for a long time in doubt as to the length of time which it took to spread through the system,—the "period of incubation," as it is termed,—although we knew in a general way that it averaged somewhere about ten days. But, about a year ago, fortune was kind to us. A nurse in one of the Parisian hospitals, in a fit of despondency, decided to commit suicide. Like a true Parisienne, she would be nothing if not up to date, and chose, as the most recherche and original method of departing this life, to swallow a pure culture of typhoid germs, which she abstracted from the laboratory. Three days later she began to complain of headache, and within a week had developed a beautiful crop of symptoms, and a typical case of typhoid, from which, under modern treatment, she promptly recovered,—a wiser and, we trust, a happier woman.

By just what avenue the infecting bacilli go from the stomach into the general system we do not know. Metschnikoff suggests that they can only penetrate the intestinal wall through wounds or abrasions of the mucous membrane, made by intestinal worms or other parasites. Certain it is that the average stomach has a considerable degree of resisting power against them, for in no known civil epidemic has the number of those who caught the disease exceeded ten per cent of the total number drinking the infected water or milk. In one or two camps in time of war the percentage has risen as high as eighteen or twenty per cent of those exposed, but this is exceptional. However, now that we know that intestinal symptoms do not constitute the entire disease, and may even be entirely absent, we strongly suspect that many cases of slight depression, with feverishness, loss of appetite, and disturbances of the digestion, which occur during an epidemic, may really have been very mild cases of the disease.

One of the singular features of the disease is that, unlike many other infections, we are entirely unable to say what conditions or influences seem either to protect against it or to predispose toward it. In the days when we believed it to be an exclusively intestinal disease it was naturally supposed that chronic digestive disturbances, and especially acute attacks of bowel trouble or dysentery, would predispose to it, but this has been entirely disproved. Soldiers in barracks with chronic digestive disturbances, and even with dysentery, have shown no higher percentage of typhoid during an epidemic than others. Nor does it seem much more likely to occur in those who are constitutionally weak, or run down, or overworked, as some of the most violent and unmanageable cases occur in vigorous men and women, who were previously in perfect health. So that, although we have unquestionably a high degree of resistance against it, since not more than one in ten exposed contracts it, and only one in ten of those who contract it dies, we have not the least idea in what direction, so to speak, to build up our resisting powers in order to increase them.

The best remedy is to destroy the disease altogether, and this could be done in five years by intelligent concerted effort. It was at one time supposed that typhoid fever was a disease exclusively confined to adult life; but it is now known to occur frequently in children, though often in such a mild and irregular form as to escape recognition. Something like seventy per cent of all cases occur between the fifteenth and the fortieth year, and it is, for some reason, though rarer, peculiarly serious and more often fatal after the fiftieth year.

When once the outer wall has been pierced, the sack of the city rapidly proceeds. The bacilli multiply everywhere, but seem for some reason to focalize chiefly in the alimentary canal, and especially the middle part of it, the small intestines. After headache, backache, and loss of appetite comes usually a mild diarrh[oe]a. This diarrh[oe]a is due to an attack of the bacillus or its toxins upon certain clumps of lymphoid tissue in the wall of the small intestine, known as the "patches of Peyer." This produces inflammation, followed by ulceration, which in severe cases may eat through the wall of a blood-vessel, causing profuse hemorrhages, or even perforate the bowel wall and set up a fatal peritonitis. The temperature begins to swing from two to five degrees above the normal level, following the usual daily vibration, and ranging from 100 degrees to 101 degrees in the morning up to 102 degrees to 105 degrees in the afternoon. The face becomes flushed.

There is usually comparatively little pain, and the patient lies in a sort of mild stupor, paying little attention to his surroundings. He is much enfeebled and seldom cares to lift his head from the pillow. A slight rash appears upon the surface of the body, but this is so faint that it would escape attention unless carefully looked for. Little groups of vesicles, containing clear fluid, appear upon the chest and abdomen. If one of these faint rose-colored spots be pricked with a needle and a drop of blood be drawn, typhoid bacilli will often be found in it, and they will also be present in the clear fluid of the tiny sweat blisters.

This condition will last for from ten days to four weeks, the patient gradually becoming weaker and more apathetic, and the temperature maintaining an afternoon level of 102 to 104 degrees. Then, in the vast majority of cases, a little decline of the temperature will be noticed. The patient begins to take a slight interest in his surroundings. He will perhaps ask for something to drink, or something to eat, instead of apathetically swallowing what is offered to him. Next day the temperature is a little lower still, and within a week, perhaps, will have returned to the normal level. The patient has lost from twenty to forty pounds, is weak as a kitten, and it may be ten days after the fever has disappeared before he asks to sit up in bed.

Then follows the period of return to health. The patient becomes a walking appetite, and, after weeks of liquid diet, will beg like a spoiled child for cookies or hard apples or pie, or something that he can set his teeth into. But his tissues are still swarming with the bacilli, and any indiscretion, either of diet, exposure, or exertion, at this time, may result in forming a secondary colony, or abscess, somewhere in the lungs, the liver, or the muscles. He must be kept quiet and warm, and abundantly, but judiciously, fed, for at least three weeks after the disappearance of the fever, if he wishes to avoid the thousand and one ambuscades set by the retreating enemy.

Now, what has happened when recovery begins? One would suppose that either the bacilli had poisoned themselves, exhausted the supplies of nourishment in the body of the patient, so that the fever had "burnt itself out," as we used to say, or that the tissues had rallied from the attack and destroyed or thrown out the invaders. But, on the contrary, we find that our convalescent patient, even after he is up and walking about, is still full of the bacilli.

To put it very crudely, what has really happened is that the body has succeeded in forming such antidotes against the poison of the bacilli that, although they may be present in enormous numbers, they can no longer produce any injurious effect. In other words, it has acquired immunity against this particular germ and its toxin. In fact, one of our newest and most reliable tests for the disease consists in a curious "clumping" or paralyzing power over cultures of the Bacillus typhosus, shown by a drop of the patient's blood, even as early as the seventh or eighth day of the illness. And, while it is an immensely difficult and complicated subject, we are justified in saying that this immunity is not merely a substance formed in the body, the stock of which will shortly become exhausted, but a faculty acquired by the body-cells, which they will retain, like other results of education, for years, and even for life. When once the body has learned the wrestling trick of throwing and vanquishing a particular germ or bacillus, it no longer has much to dread from that germ. This is why the same individual is seldom attacked the second time by scarlet fever, measles, typhoid, and smallpox.

While, however, the individual may be entirely immune to the germs of a given disease, he may carry them in his body in enormous numbers, and infect others while escaping himself.

This is peculiarly true of typhoid, and we are beginning to extend our sanitary care over recovered patients, not merely to the end of acute illness, but for the period of at least a month after they have apparently recovered. Several most disquieting cases are on record of so-called "typhoid carriers," or individuals who, having recovered from the disease itself, carried and spread the infection wherever they went for months and even years afterward. This, however, is probably a rare state of affairs, though a recent German health bulletin reports the discovery of some twenty cases during the past year. The lair of the bacilli is believed to be the gall-bladder.

As to treatment, it may be broadly stated that all authorities and schools are for once practically agreed:—

First, that we have no known specific drug for the cure of the disease.

Second, that we are content to take a leaf out of nature's book, and follow—so to speak—her instinctive methods: first of all, by putting the patient to bed the moment that a reasonable suspicion of the disease is formed; this conserves his strength, and greatly diminishes the danger of serious complications; cases of "walking typhoid" have among the highest death-rates; second, by meeting the great instinctive symptom of fever patients since the world began, thirst, encouraging the patient to drink large quantities of water, taking care, of course, that the water is pure and sterile. The days when we kept fever patients wrapped up to their necks in woolen blankets in hot, stuffy rooms, and rigorously limited the amount of water that they drank—in other words, fought against nature in the treatment of disease—have passed. A typhoid-fever patient now is not only given all he wants to drink, but encouraged to take more, and some authorities recommend an intake of at least three or four quarts, and, better, six and eight quarts a day. This internal bath helps not only to allay the temperature, but to make good the enormous loss by perspiration from the fevered skin, and to flush the toxins out of the body.

Third, by liberal and regular feeding chiefly with some liquid or semi-liquid food, of which milk is the commonest form. The old attitude of mind represented by the proverb, "Feed a cold and starve a fever," has completely disappeared. One of the fathers of modern medicine asked on his death-bed, thirty years ago, that his epitaph should be, "He fed fevers."

Fourth. We respond to the other great thirst of fever patients, for coolness, by sponge baths and tub baths, whenever the temperature rises above a certain degree.

Simple as these methods sound, they are extremely troublesome to put into execution, and require the greatest skill and judgment in their carrying out. But intelligent persistence in the careful elaboration of these methods of nature has resulted in already cutting the death-rate in two,—from fifteen or twenty per cent to less than ten per cent,—and where the full rigor of the tub bath is carried out it has been brought down to as low as five per cent.

Meanwhile the bacteriologists are steadily at work on a vaccine or antitoxin. Wright, of the English Army Medical Staff, has already secured a serum, which has given remarkable results in protecting regiments sent out to South Africa and other infected regions. Chantemesse has imported some six hundred successive cases treated with an antitoxin, whose mortality was only about a third of the ordinary hospital rate, and the future is full of promise.



CHAPTER X

DIPHTHERIA

That was a dark and stern saying, "Without the shedding of blood there is no remission," and, like all the words of the oracles, of limited application. But it proves true in some unexpected places outside of the realm of theology. Was there something prophetic in the legend that it was only by the sprinkling of the blood of the Paschal Lamb above the doorway that the plague of the firstborn could be stayed? To-day the guinea-pig is our burnt offering against a plague as deadly as any sent into Egypt.

Scarcely more than a decade ago, as the mother sat by the cradle of her firstborn, musing over his future, one moment fearfully reckoning the gauntlet of risks that his tiny life had to run, and the next building rosy air-castles of his happiness and success, there was one shadow that ever fell black and sinister across his tiny horoscope. Certain risks there were which were almost inevitable,—initiation ceremonies into life, mild expiations to be paid to the gods of the modern underworld, the diseases of infancy and of childhood. Most of these could be passed over with little more than a temporary wrinkle to break her smile. They were so trivial, so comparatively harmless: measles, a mere reddening of the eyelids and peppering of the throat, with a headache and purplish rash, dangerous only if neglected; chicken-pox, a child's-play at disease; scarlatina, a little more serious, but still with the chances of twenty to one in favor of recovery; diphtheria—ah! that drove the smile from her face and the blood from her lips. Not quite so common, not so inevitable as a prospect, but, as a possibility, full of terror, once its poison had passed the gates of the body fortress. The fight between the Angel of Life and the Angel of Death was waged on almost equal terms, with none daring to say which would be the victor, and none able to lift a hand with any certainty to aid.

Nor was the doctor in much happier plight. Even when the life at stake was not one of his own loved ones,—though from the deadly contagiousness of the disease it sadly often was (I have known more doctors made childless by diphtheria than by any other disease except tuberculosis),—he faced his cases by the hundred instead of by twos and threes. The feeling of helplessness, the sense of foreboding, with which we faced every case was something appalling. Few of us who have been in practice twenty years or more, or even fifteen, will ever forget the shock of dismay which ran through us whenever a case to which we had been summoned revealed itself to be diphtheria. Of course, there was a fighting chance, and we made the most of it; for in the milder epidemics only ten to twenty per cent of the patients died, and even in the severest a third of them recovered. But what "turned our liver to water"—as the graphic Oriental phrase has it—was the knowledge which, like Banquo's ghost, would not down, that while many cases would recover of themselves, and in many border-line ones our skill would turn the balance in favor of recovery, yet if the disease happened to take a certain sadly familiar, virulent form we could do little more to stay its fatal course than we could to stop an avalanche, and we never knew when a particular epidemic or a particular case would take that turn. "Black" diphtheria was as deadly as the Black Death of the Middle Ages.

The disease which caused all this terror and havoc is of singular character and history. It is not a modern invention or development, as is sometimes believed, for descriptions are on record of so-called "Egyptian ulcer of the throat" in the earliest centuries of our era; and it would appear to have been recognized by both Hippocrates and Galen. Epidemics of it also occurred in the Middle Ages; and, coming to more recent times, one of the many enemies which the Pilgrim Fathers had to fight was a series of epidemics of this "black sore throat," of particularly malignant character, in the seventeenth century. Nevertheless, it does not seem to have become sufficiently common to be distinctly recognized until it was named as a definite disease, and given the title which it now bears, by the celebrated French physician, Bretonneau, about eighty years ago. Since then it has become either more widely recognized or steadily more prevalent, and it is the general opinion of pathologists that the disease, up to some thirty or forty years ago, was steadily increasing, both in frequency and in severity.

So that we have not to deal with a disease which, like the other so-called diseases of childhood, has gradually become milder and milder by a sort of racial vaccination, with survival of the less susceptible, but one which is still full of virulence and of possibilities of future danger.

Unlike the other diseases of childhood, also, one attack confers no positive immunity for the future, although it greatly diminishes the probabilities; and, further, while adults do not readily or frequently catch the disease, yet when they do the results are apt to be exceedingly serious. Indeed, we have practically come to the conclusion that one of the main reasons why adults do not develop diphtheria so frequently as children, is that they are not brought into such close and intimate contact with other children, nor are they in the habit of promptly and indiscriminately hugging and kissing every one who happens to attract their transient affection, and they have outgrown that cheerful spirit of comradeship which leads to the sharing of candy in alternate sucks, and the passing on of slate-pencils, chewing-gum, and other objets d'art from hand to hand, and from mouth to mouth. Statistics show that of nurses employed in diphtheria wards, before the cause or the exact method of contagion was clearly understood, nearly thirty per cent developed the disease; and even with every modern precaution there are few diseases which doctors more frequently catch from their patients than diphtheria. It is a significant fact that the risk of developing diphtheria is greatest precisely at the ages when there is not the slightest scruple about putting everything that may be picked up into the mouth,—namely, from the second to the fifth year,—and diminishes steadily as habits of cleanliness and caution in this regard are developed, even though no immunity may have been gained by a mild or slight attack of the disease. The tendency to discourage and forbid the indiscriminate kissing of children, and the crusade against the uses of the mouth as a pencil-holder, pincushion, and general receptacle for odds and ends, would be thoroughly justified by the risks from diphtheria alone, to say nothing of tuberculosis and other infections.

In addition to being almost the only common disease of childhood which is not mild and becoming milder, diphtheria is unique in another respect, and that is its point of attack. Just as tuberculosis seizes its victims by the lungs, and typhoid fever by the bowels, diphtheria—like the weasel—grips at the throat. Its bacilli, entering through the mouth and gaining a foothold first upon the tonsils, the palate, or back of the throat (pharynx), multiply and spread until they swarm down into the larynx and windpipe, where their millions, swarming in the mesh of fibrin poured out by the outraged blood-vessels, grow into the deadly false membrane which fills the air-tube and slowly strangles its victim to death.

The horrors of a death like that can never fade from the memory of one who has once seen it, and will outweigh the lives of a thousand guinea-pigs. No wonder there was such a widespread and peculiar horror of the disease, as of some ghostly thug or strangler.

But not all of the dread of diphtheria went under its own name. Most of us can still remember when the commonest occupant of the nursery shelf was the bottle of ipecac or soothing-syrup as a specific against croup. The thing that most often kept the mother or nurse of young children awake and listening through the night-watches was the sound of a cough, and the anxious waiting to hear whether the next explosion had a "croupy" or brassy sound. It was, of course, early recognized that there were two kinds of croup, the so-called "spasmodic" and the "membranous," the former comparatively common and correspondingly harmless, the latter one of the deadliest of known diseases. The fear that made the mother's heart leap into her mouth as she heard the ringing croup-cough was lest it might be membranous, or, if spasmodic, might turn into the deadly form later. To-day most young mothers hardly know the name of wine of ipecac or alum, and the coughs of young children awaken little more terror than a similar sound in an adult. Croup has almost ceased to be one of the bogies of the nursery. And why? Because membranous croup has been discovered to be diphtheria, and children will not develop diphtheria unless they have been exposed to the contagion, while, if they should be, we have a remedy against it.

He was a bold man who first ventured to announce this, and for years the battle raged hotly. It was early admitted that certain cases of so-called membranous croup in children occurred after or while other members of the family or household had diphtheria; and for a time the opposing camps used such words as "sporadic" or scattered croup, which was supposed to come of itself, and "epidemic" or contagious croup, which was diphtheria. Now, however, these distinctions are swept away, and boards of health require isolation and quarantine against croup exactly as against any other form of diphtheria.

Cases of fatal croup still occasionally occur which cannot be directly traced to other cases of diphtheria, but the vast majority of them are clearly traceable to infection, usually from some case in another child, which was so mild that it was not recognized as diphtheria until the baby became "croupy" and search was made through the family throats for the bacilli.

For years we were in doubt as to the cause of diphtheria. Half a dozen different theories were advanced, bad sewerage, foul air, overcrowding; but it was not until shortly after the Columbus-like discovery, by Robert Koch, of the new continent of bacteriology, that the germ which caused it was arrested, tried, and found guilty, and our real knowledge of and control over the disease began. This was in 1883, when the bacteriologist Klebs discovered the organism, followed a few months later (in 1884) by Loeffler, who made valuable additions to our knowledge of it; so that it has ever since been known as the Klebs-Loeffler bacillus. This put us upon solid ground, and our progress was both sure and rapid: in ten years our knowledge of the causation, the method of spread, the mode of assault upon the body-fortress, and last, but not least, the cure, stood out clear cut as a die, a model and a prophecy of what may be hoped for in most other contagious diseases.

Great as is the credit to which bacteriologists are entitled for this splendid piece of scientific progress, there was another co-laborer, a silent partner, with them in all this triumph, an unsung hero and martyr of science who deserves his meed of praise—the tiny guinea-pig. He well deserves his niche in the temple of fame; and as other races and ages have worshiped the elephant, the snake, and the sacred cow, so this age should erect its temples to the guinea-pig. From one of the most trifling and unimportant,—kept merely as a pet and curiosity by the small boys of all ages,—he has become, after the horse, the cow, the pig, and the sheep, easily our most useful and important domestic animal. It may be urged that he deserves no credit, since his sacrifice—though of inestimable value—was entirely involuntary on his own part; but this should only make us the more deeply bound to acknowledge our obligation to him.

By a stern necessity of fate, which no one regrets more keenly than the laboratory workers themselves, the guinea-pig has had to be used as a stepping-stone for every inch of this progress. Upon it were conducted every one of the experiments whose results widened our knowledge, until we found that this bacillus and no other would cause diphtheria; that instead of getting, like many other disease-germs, into the blood, it chiefly limited itself to growing and multiplying upon a comparatively small patch of the body-surface, most commonly of the throat; that most of its serious and fatal results upon the body were produced, not by the entrance of the germs themselves into the blood, but by the absorption of the toxins or poisons produced by them on the moist surface of the throat, just as the yeast plant will produce alcohol in grape juice or sweet cider.

Here was a most important clew. It was not necessary to fight the germs themselves in every part of the body, but merely to introduce some ferment or chemical substance which would have the power of neutralizing their poison. Instantly attention was turned in this direction, and it was quickly found that if a guinea-pig were injected with a very small dose of the diphtheria toxin and allowed to recover, he would then be able to throw off a still larger dose, until finally, after a number of weeks, he could be given a dose which would have promptly killed him in the beginning of the experiments, but which he now readily resisted and recovered from. Evidently some substance was produced in his blood which was a natural antidote for the toxin, and a little further search quickly resulted in discovering and filtering out of his body the now famous antitoxin. A dose of this injected into another guinea-pig suffering from diphtheria would promptly save its life.

Could this antitoxin be obtained in sufficient amounts to protect the body of a human being? The guinea-pig was so tiny and the process of antitoxin-forming so slow, that we naturally turned to larger animals as a possible source, and here it was quickly found that not only would the goat and the horse develop this antidote substance very quickly and in large amounts, but that a certain amount of it, or a substance acting as an antitoxin, was present in their blood to begin with. Of the two, the horse was found to give both the stronger antitoxin and the larger amounts of it, so that he is now exclusively used for its production.

After his resisting power had been raised to the highest possible pitch by successive injections of increasing doses of the toxin, and his serum (the watery part of the blood which contains the healing body) had been used hundreds and hundreds of times to save the lives of diphtheria-stricken guinea-pigs, and had been shown over and over again to be not merely magically curative but absolutely harmless, it was tried with fear and trembling upon a gasping, struggling, suffocating child, as a last possible resort to save a life otherwise hopelessly doomed. Who could tell whether the "heal-serum," as the Germans call it, would act in a human being as it had upon all the other animals? In agonies of suspense, vibrating between hope and dread, doctors and parents hung over the couch. What was their delight, within a few hours, to see the muscles of the little one begin to relax, the fatal blueness of its lips to diminish, and its breathing become easier. In a few hours more the color had returned to the ashen face and it was breathing quietly. Then it began to cough and to bring up pieces of the loosened membrane that had been strangling it. Another dose was eagerly injected, and within twenty-four hours the child was sleeping peacefully—out of danger. And the most priceless and marvelous life-saving weapon of the century had been placed in the hand of the physician.

Of course there were many disappointments and failures in the earlier cases. Our first antitoxins were too weak and too variable. We were afraid to use them in sufficient doses. Often their injection would not be consented to until the case had become hopeless. But courage and industry have conquered these difficulties one after another, until now the fact that the prompt and intelligent use of antitoxin will effect a cure of from ninety to ninety-five per cent of all cases of diphtheria is as thoroughly established as any other fact in medicine. The mass of figures from all parts of the world in support of its value has become so overwhelming that it is neither possible nor necessary to specify them in detail. The series of Bayeaux, covering two hundred and thirty thousand cases of diphtheria, chiefly from hospitals and hence of the severest type, showing that the death-rate had been reduced from over fifty-five per cent to below sixteen per cent already, and that this decrease was still continuing, will serve as a fair sample.

Three-quarters of even this sixteen per cent mortality is due to delay in the administration of the antitoxin, as is vividly shown in thousands of cases now on record, classified according to the day of the disease on which the antitoxin was given, of which MacCombie's "Report of the London Asylums Board" is a fair type. Of one hundred and eighty-seven cases treated the first day of the disease, none died; of eleven hundred and eighty-six injected on the second day of the disease, four and a half per cent died; of twelve hundred and thirty-three not treated until the third day of the disease, eleven per cent died; of nine hundred and sixty-three cases escaping treatment until the fourth day, seventeen per cent died; while of twelve hundred and sixty not seen until the fifth day, twenty per cent died. In other words, the chances for cure by the antitoxin are in precise proportion to the earliness with which it is administered, and are over four times as great during the first two days of the disease as they are after the fourth day. One "stick" in time saves five.

This brings us sharply to the fact that the most important factor in the cure of diphtheria, just as in the case of tuberculosis, is early recognition. How can this be secured? Here again the bacteriologist comes to our relief, and we needed his aid badly. The symptoms of a mild case of diphtheria for the first two, or even three, days are very much like those of an ordinary sore throat. As a rule, even the well-known membrane does not appear in sufficient amounts to be recognizable by the naked eye until the middle of the second, or sometimes even of the third, day. By any ordinary means, then, of diagnosis, we would often be in doubt as to whether a case were diphtheria or not, until it was both well advanced and had had time to infect other members of the family. With the help of the laboratory, however, we have a prompt, positive, and simple method of deciding at the very earliest stage. We merely take a sterilized swab of cotton on the end of a wire, rub it gently over the surface of the throat and tonsils, restore it to its glass tube, smearing it over the surface of some solidified blood-serum placed at the bottom of the tube, close the tube and send it to the nearest laboratory. The culture is put into an incubator at body heat, the germs sown upon the surface of the blood-serum grow and multiply, and in twelve hours a positive diagnosis can be made by examining this growth with a microscope. Often, just smearing the mucus swabbed out of the throat over the surface of a glass slide, staining this smear, and putting it under a microscope, will enable us to decide within an hour. These tubes are now provided by all progressive city boards of health, and can be had free of charge at depots scattered all over the city, for use in any doubtful case, within half an hour. Twelve hours later a free report can be had from the public laboratory. If every case of suspicious sore throat in a child were promptly swabbed out, and a smear from the swab examined at a laboratory, it would not be long before diphtheria would be practically exterminated, as smallpox has been by vaccination, and this is what we are working toward and looking forward to.

Our knowledge of the precise cause of diphtheria, the Klebs-Loeffler bacillus, has furnished us not only with the cure, but also with the means of preventing its spread. While under certain circumstances, particularly the presence of moisture and the absence of light, this germ may live and remain virulent for weeks outside of the body, careful study of its behavior under all sorts of conditions has revealed the consoling fact that its vitality outside of the human or some other living animal body is low; so that it is relatively seldom carried from one case to another by articles of clothing, books, or toys, and comparatively seldom even through a third party, except where the latter has come into very close contact with the disease, like a doctor, a nurse, or a mother, or—without disrespect to the preceding—a pet cat or dog.

More than this, the bacillus must chiefly be transmitted in the moist condition and does not float in the air at all, clinging only to such objects as may have become smeared with the mucus from the child's throat, as by being coughed or sneezed upon. As with most of our germ-enemies, sunlight is its deadliest foe, and it will not live more than two or three days exposed to sunshine. So the principal danger against which we must be on our guard is that of direct personal contact, as in kissing, in the use of spoons or cups in common, in the interchange of candy or pencils, or through having the hands or clothing sprayed by a cough or a sneeze.

The bacillus comparatively seldom even gets on the floor or walls of a room where reasonable precautions against coughing and spitting have been taken; but it is, of course, advisable thoroughly to disinfect and sterilize the room of a patient and all its contents with corrosive sublimate and formalin, as a number of cases are on record in which the disease has been carried through books and articles of clothing which had been kept in damp, dark places for several months. The chief method of spread is through unrecognized mild cases of the disease, especially of the nasal form. For this reason boards of health now always insist upon smears being made from the throats and noses of every other child in the family or house where a case of diphtheria is recognized. No small percentages of these are found to be suffering from a mild form of the disease, so slight as to cause them little inconvenience and no interference with their attending school. Unfortunately, a case caught from one of these mild forms may develop into the severest laryngeal type. If a child is running freely at the nose, keep it at home or keep your own child away from it. A profuse nasal discharge is generally infectious, in the case of influenza or other "colds," if not of diphtheria.

This also emphasizes the necessity for a thorough and expert medical inspection of school-children, to prevent these mild cases from spreading disease and death to their fellows. By an intelligent combination of the two methods, home examination of every infected family and strict school inspection, there is little difficulty in stamping out promptly a beginning infection before it has had time to reach the proportions of an epidemic.

One other step makes assurance doubly sure, and that is the prompt injection of all other children and young adults living in the family, where there is a case of diphtheria, with small doses of the antitoxin for preventive purposes. Its value in this respect has been only secondary to its use as a cure. There are now thousands of cases on record of children who had been exposed to diphtheria or were in hospitals where they were in danger of becoming exposed to it, with the delightful result that only a very small per cent of those so protected developed the disease, and of these not a single one died! This protective vaccination, however, cannot be used on a large scale, as in the case of smallpox, for the reason that the period of protection is a comparatively short one, probably not exceeding two or three weeks.

Suppose that, in spite of all our precautions, the disease has gained a foothold in the throat, what will be its course? This will depend, first of all, upon whether the invading germs have lodged in their commonest point of attack, the tonsils, palate, and upper throat, or have penetrated down the air-passages into the larynx or voice-organ. In the former, which is far the commoner case, their presence will cause an irritation of the surface cells which brings out the leucocyte cavalry of the body to the defense, together with squads of the serum or watery fluid of the blood containing fibrin. These, together with the surface-cells, are rapidly coagulated and killed by the deadly toxin; and their remains form a coating upon the surface, which at first is scarcely perceptible, a thin, grayish film, but which in the course of twenty-four to forty-eight hours rapidly thickens to the well-known and dreaded false membrane. Before, however, it has thickened in more than occasional spots or patches, the toxin has begun to penetrate into the blood, and the little patient will complain of headache, feverishness, and backache, often—indeed, usually—before any very marked soreness in the throat is complained of. Roughly speaking, attacks of sore throat, which begin first of all with well-marked soreness and pain in the throat, followed later by headache, backache, and fever, are not very likely to be diphtheria. The bacilli multiply and increase in their deadly mat on the surface of the throat, larger and larger amounts of the poison are poured into the blood, the temperature goes up, the headache increases, the child often begins to vomit, and becomes seriously ill. The glands of the neck, in their efforts to arrest and neutralize the poison, become swollen and sore to the touch, the breath becomes foul from the breaking down of the membrane in the throat, the pulse becomes rapid and weak from the effect of the poison upon the heart, and the dreaded picture of the disease rapidly develops.

This process in from sixty to eighty per cent of cases will continue for from three to seven days, when a check will come and the condition will gradually improve. This is a sign that the defensive tissues of the body have succeeded in rallying their forces against the attack, and have poured out sufficient amounts of their natural antitoxin to neutralize the poisons poured in by the invaders. The membrane begins to break down and peel off the throat, the temperature goes down, the headache disappears, the swelling in the glands of the neck may either subside or go on to suppuration and rupture, but within another week the child is fairly on the way to recovery.

Should the invaders, however, have secured a foothold in the larynx, then the picture is sadly different. The child may have even less headache, temperature, and general sense of illness; but he begins to cough, and the cough has a ringing, brassy sound. Within forty-eight, or even twenty-four, hours he begins to have difficulty in respiration. This rapidly increases as the delicate tissues of the larynx swell under the attack of the poison, and the very membrane which is created in an attempt at defense becomes the body's own undoing by increasing the blocking of the air-passages. The difficulty of breathing becomes greater and greater, until the little victim tosses continually from side to side in one constant, agonizing struggle for breath. After a time, however, the accumulation of carbon dioxide in the blood produces its merciful narcotic effect, and the struggles cease. The breathing becomes shallower and shallower, the lips become first blue, then ashy pale, and the little torch of life goes out with a flicker. This was what we had to expect, in spite of our utmost effort, in from seventy to ninety per cent of these laryngeal cases, before the days of the blessed antitoxin. Now we actually reverse these percentages, prevent the vast majority of cases from developing serious laryngeal symptoms at all, and save from seventy to eighty per cent of those who do.