Preventable Diseases. Woods Hutchinson
free and unattached. They float at large in the blood-current, much as their original ancestor, the amœba, did in the water of the stagnant ditch. And, curiously enough, the less numerous of the two great classes, the white, or leucocytes, are in appearance, structure, pseudopodic movements, and even method of engulfing food, almost exact replicas of their most primitive ancestor.
There is absolutely no fixed means of communication between the blood-corpuscles and the rest of the body, not even by the tiniest branch of the great nerve-telegraph system, and yet they are the most loyal and devoted class among all the citizens of the cell-republic. They are called hither and thither partly by messenger-substances thrown into the blood, known as hormones, partly by the "smell of the battle afar off," the toxins of inflammation and infection as they pour through the blood.
The red ones lose their nuclei, their individuality, in order to become sponges, capable of saturating themselves with oxygen and carrying it to the gasping tissues. The white are the great mounted police, the sanitary patrol of the body. The moment that the alarm of injury is sounded in a part, all the vessels leading to it dilate, and their channels are crowded by swarms of the red and white hurrying to the scene. The major part of the activity of the red cells can be accounted for by the mechanism of the heart and blood-vessels. They are simply thrown there by the handful and the shovelful, as it were, like so many pebbles or bits of chalk.
But the behavior of the white cells goes far beyond this. We are almost tempted to endow them with volition, though they are of course drawn or driven by chemical and physical attractions, like iron-filings by a magnet, or an acid by a base. Not only do all those normally circulating in the blood flowing through the injured part promptly stop and begin to scatter themselves through the underbrush and attack the foe at close quarters, but, as has been shown by Cabot's studies in leucocytosis, the moment that the red flag of fever is hoisted, or the inflammation alarm is sounded, the leucocytes come rushing out from their feeding-grounds in the tissue-interspaces, in the lymph-channels, in the great serous cavities, and pour themselves into the blood-stream, like minute-men leaving the plough and thronging the highways leading towards the frontier fortress which has been attacked. Arrived at the spot, if there be little of the pomp and pageantry of war in their movements, their practical devotion and heroism are simply unsurpassed anywhere, even in song and story. They never think of waiting for reinforcements or for orders from headquarters. They know only one thing, and that is to fight; and when the body has brought them to the spot, it has done all that is needed, like the Turkish Government when once it has got its sturdy peasantry upon the battlefield: they have not even the sense to retreat. And whether they be present in tens, or in scores, or in millions, each one hurls himself upon the toxin or bacillus which stands directly in front of him. If he can destroy the bacillus and survive, so much the better; but if not, he will simply overwhelm him by the weight of his body-mass, and be swept on through the blood-stream into the great body-sewers, with the still living bacillus literally buried in his dead body. Like Arnold Winkelried, he will make his body a sheath for a score of the enemy's spears, so that his fellows can rush in through the gap that he has made. And it makes no difference whatever if the first ten or hundred or thousand are instantly mowed down by the bacillus or its deadly toxins, the rear ranks sweep forward without an instant's hesitation, and pour on in a living torrent, like the Zulu impis at Rorke's Drift, until the bacilli are battered down by the sheer impact of the bodies of their assailants, or smothered under the pile of their corpses. When this has happened, in the language of the old surgeon-philosophers, "suppuration is established," and the patient is saved.
Or if, as often happens, an antitoxin is formed, which protects the whole body, this is largely built out of substances set free from the bodies of slain leucocytes. And the only thing that dims our vision to the wonder and beauty of this drama, is that it happens every day, and we term it prosaically "the process of repair," and expect it as a matter of course. Every wound-healing is worthy of an epic, if we could only look at it from the point of view of these citizens of our great cell-republic. And if we were to ask the question, "Upon what does their peculiar value to the body-politic depend?" we should find that it was largely the extent to which they retained their ancestral characteristics. They are born in the lymph-nodes, which are simply little islands of tissue of embryonic type, preserved in the body largely for the purpose of breeding this primitive type of cells. They are literally the Indian police, the scavengers, the Hibernians, as it were, of the entire body. They have the roving habits and fighting instincts of the savage. They cruise about continually through the waterways and marshes of the body, looking for trouble, and, like their Hibernian descendants, wherever they see a head they hit it. They are the incarnation of the fighting spirit of our ancestors, and if it were not for their retention of this characteristic in so high a degree, many classes of our fixed cells would not have been able to subside into such burgher like habits.
Although even here, as we shall see, it is only a question of quickness of response, for while the first bands of the enemy may be held at bay by the leucocyte cavalry, and a light attack repelled by their skirmish-line, yet when it comes to the heavy fighting of a fever-invasion, it is the slow but substantial burgher-like fixed cells of the body which form the real infantry masses of the campaign. And I believe that upon the proportional relation between these primitive and civilized cells of our body-politic will depend many of the singular differences, not only in degree but also in kind, in the immunity possessed by various individuals. While some surgeons and anatomists will show a temperature from the merest scratch, and yet either never develop any serious infection or display very high resisting power in the later stages, others, again, will stand forty slight inoculations with absolute impunity, and yet, when once the leucocyte-barrier is broken down, will make apparently little resistance to a fatal systemic infection. And this, of course, is only one of a score of ways in which the leucocytes literally pro patria moriuntur. Our whole alimentary canal is continually patrolled by their squadrons, poured into it by the tonsils above and Peyer's patches below; if it were not for them we should probably be poisoned by the products of our own digestive processes.
If, then, the cells of the body-republic retain so much of their independence and individuality in health, does it not seem highly probable that they do also in disease? This is known to be the case already in many morbid processes, and their number is being added to every day. The normal activities of any cell carried to excess may constitute disease, by disturbing the balance of the organism. Nay, most disease-processes on careful examination are found to be at bottom vital, often normal to the cells concerned in them. The great normal divisions of labor are paralleled by the great processes of degeneration into fat, fibrous tissue, and bone or chalk. A vital chemical change which would be perfectly healthy in one tissue or organ, in another may be fatal.
Ninety-nine times out of a hundred any group of cells acts loyally in the interests of the body; once in a hundred some group acts against them, and for its own, and disease is the result. There is a perpetual struggle for survival going on between the different tissues and organs of the body. Like all other free competition, as a rule, it inures enormously to the benefit of the body-whole. Exceptionally, however, it fails to do so, and behold disease. This struggle and turmoil is not only necessary to life—it is life. Out of the varying chances of its warfare is born that incessant ebb and flow of chemical change, that inability to reach an equilibrium, which we term "vitality." The course of life, like that of a flying express train, is not a perfectly straight line, but an oscillating series of concentric curves. Without these oscillations movement could not be. Exaggerate one of them unduly, or fail to rectify it by a rebound oscillation, and you have disease.
Or it is like the children's game of shuttlecock. So long as the flying shuttle keeps moving in its restless course to and fro, life is. A single stop is death. The very same blow which, rightly placed, sends it like an arrow to the safe centre of the opposing racket, if it fall obliquely, or even with too great or too little force, drives it perilously wide of its mark. It can recover the safe track only by a sudden and often violent lunge of the opposing racket. The straight course is life, the tangent disease, the saving lunge recovery.
One and the same force produces all.
In the millions of tiny blows dealt every minute in our body-battle, what wonder if some go wide of the mark!
CHAPTER