Supposing that the poison be of more insidious form, a germ or a ptomaine, for instance, which slips past these outer "firing-out" defenses of the food-tube and arouses no suspicion of its presence until it has been partially digested and absorbed into the blood. Again, resourceful nature is ready with another line of defense. It was for a long time a puzzle why every drop of the blood containing food and its products absorbed from the alimentary food-canal had to be carried, often by a most roundabout course, to and through the liver, before it could reach any part of the general system. Here was the largest and most striking organ in the body, and it was as puzzling as it was large. We knew in some crude way that it "made blood," that it prepared the food-products for use by the body-cells, and that it secreted the bile; but this latter secretion had little real digestive value, and the other changes seemed hardly important enough to demand that every drop of the blood coming from the food-tube should pass through this custom-house. Now, however, we know that in addition to its other actions, the liver is a great poison-sponge or toxin-filter, for straining out of the blood poisonous or injurious materials absorbed from the food, and converting them into harmless substances. It is astonishing what a quantity of these poisons, whether from the food or from germs swallowed with it, the liver is capable of dealing with—destroying them, converting them, and acting as an absolute barrier to their passage into the general system. But sometimes it is overwhelmed by appalling odds; some of the invaders slip through its lines into the general circulation, producing headache, backache, fever, and a "dark-brown taste in the mouth"; and, behold, we are bilious, and proceed to blame the poor liver. We used to pour in remedies to "stir it up," to "work on it"—which was about as rational as whipping a horse when he is down, instead of cutting his harness or taking his load off. Nowadays we stop the supply of further food-poisons by stopping eating, assist nature in sweeping out or neutralizing the enemies that are still in the alimentary canal, flush the body with pure water, put it at rest—and trust the liver. Biliousness is a sign of an overworked liver. If it wasn't working at all, we shouldn't be bilious: we should be dead, or in a state of collapse.

Moral: Don't rush for some remedy with which to club into insensibility every symptom of disease as soon as it puts in an appearance. Give nature a little chance to show what she intends to do before attempting to stop her by dosing yourself with some pain-reliever or colic cure. Don't trust her too blindly, for the best of things may become bad in extremes, and the body may become so panic-stricken as to keep on throwing overboard, not merely the poisons, but its necessary daily food, if the process be allowed to continue too long.

This is where the doctor comes in. This is the point at which it takes brains to succeed in the treatment of disease—to decide just how far nature knows what she is doing, even in her most violent expulsive methods, and is to be helped; and just when she has lost her head, or got into a bad habit, and must be thwarted. This much we feel sure of, and it is one of the keynotes of the attitude of modern medicine, that a large majority of the symptoms of disease are really nature's attempts to cure it.

This is admirably shown in our modern treatment of fevers. These we now know to be due to the infection of the body by more or less definitely recognized disease-germs or organisms. Fever is a complicated process, and we are still in the dark upon many points in regard to it, but we are coming more and more firmly to the conclusion that most of its symptoms are a part of, or at least incidents in, the fight of the body against the invading army. The flushed and reddened skin is due to the pumping of large quantities of blood through its mesh, in order that the poisons may be got rid of through the perspiration. The rapid pulse shows the vigor with which the heart is driving the blood around the body, to have its poisons neutralized in the liver, burned up in the lungs, poured out by the kidneys and the skin. The quickened breathing is the putting on of more blast in the lung poison-crematory. It is possible that even the rise of temperature has an injurious effect upon the invading germs or assists the body in their destruction.

In the past we have blindly fought all of these symptoms. We shut our patients up in stove-heated rooms with windows absolutely closed, for fear that they would "catch cold." We took off the sheets and piled blankets upon the bed, setting a special watch to see that the wretched sufferer did not kick them off. We discouraged the drinking of water and insisted on all drinks that were taken being hot or lukewarm. Nowadays all this is changed. We throw all the windows wide-open, and even put our patients out of doors to sleep in the open air, whether it be typhoid, tuberculosis, or pneumonia; knowing that not only they will not "catch cold," but that, as their hurried breathing indicates, they need all the oxygen they can possibly get, to burn up the poison poured out in the lungs and from the skin. We encourage the patient to drink all the cool, pure water he will take, sometimes gallons in a day, knowing that his thirst is an indication for flushing and flooding all the great systems of the body sewers. Instead of smothering him in blankets, we put him into cold packs, or put him to soak in cool water.

In short, we trust nature instead of defying her, coöperate with her in place of fighting her,—and we have cut down the death-rate of most fevers fifty to seventy-five per cent already. Plenty of pure, cool water internally, externally, and eternally, rest, fresh air, and careful feeding, are the best febrifuges and antipyretics known to modern medicine. All others are frauds and simply smother a symptom without relieving its cause, with the exception of quinine in malaria, mercury, and the various antitoxins in their appropriate diseases, which act directly upon the invading organism.

Underneath all this storm and stress of the fever paroxysm, nature is quietly at work elaborating her antidote. In some marvelous fashion, which we do not even yet fully understand, the cells of the body are producing in ever-increasing quantities an anti-body, or antitoxin, which will unite with the toxin or poison produced by the hostile germs and render it entirely harmless. By a curious paradox of the process, it does not kill the germs themselves. It may not even stop their further multiplication. Indeed, it utilizes part of their products in the formation of the antitoxin; but it domesticates them, as it were—turns them from dangerous enemies into harmless guests.

The treaty between these germs and the body, however, is only of the "most-favored-nation" class; for let these tamed and harmless friends of the family escape and enter the body of another human being, and they will attack it as virulently as ever.

Now, where and how did nature ever succeed in getting the rehearsal and the practice necessary to build up such an extraordinary and complicated system of defense as this? Take your microscope and look at a drop of fluid from the mouth, the gums, the throat, the stomach, the bowels, and you will find it simply swarming with bacteria, bacilli, and cocci, each species of which numbers its billions. There are thirty-three species which inhabit the mouth and gums alone! We are literally alive with them; but most of them are absolutely harmless, and some of them probably slightly helpful in the processes of digestion. In fevers and infections the body merely applies to disease-germs the tricks which it has learned in domesticating these millions of harmless vegetable inhabitants.

Still more curious—there is a distinct parallel between the method in which food-materials are split up and prepared for assimilation by the body, and the method adopted in breaking up and neutralizing the toxins of disease-germs. It is now known that poisons are formed in the process of digesting and absorbing the simplest and most wholesome foods; and the liver uses the skill which it has gained in dealing with these "natural poisons" in disposing of the toxins of germs.