Yet the fact that most people suffer from illness is no reason for calling it a natural condition. It is health that is natural; illness is an anomaly. Medical men themselves are the first to recognise the truth of this statement. Animals as a rule are sound and vigorous so long as they are in a wild state. It is only when they are in captivity that they become delicate. Similarly savages are much freer from disease than civilised races. It is when they live in artificial surroundings that they become prone to sickness.

Health is not a negative thing. It is a state in which every part is sound and acts in harmony with every other part.

The nature of health.

A motor-car consists of a great number of different parts—the gear, the engine, the petrol supply, the firing. It is not sufficient that each section should be in good order. For each must also fit in, both mechanically and in point of time, with every other. The petrol pipe may be clear, but unless the spark reaches the cylinders exactly in the nick of time there will be misfiring, and a loss of power in consequence.

This loss of power is not the only harm done. It means that there will be unnecessary friction also, causing extra wear and tear to the engine and gear. If this occurs but seldom, and is put right at once when detected, little damage may be done. If repeated often, and allowed to go on uncared for, the whole structure of the car will suffer and the life of the machine be shortened.

It does not follow that the car will come to a standstill. It will continue to run, but badly. For like every other engine, it has the faculty of compensation. That is to say, when one part is out of order other parts will take on some of its work, and help, for a time at least, to make good the deficiency.

For instance, in a four-cylinder car one of the cylinders may cease to act. Yet the other three will take on a certain part of the work, and help to some extent to make up the deficiencies of the faulty one.

This will be only for a time, however, for the additional strain will slowly but surely have a bad effect on the rest of the engine, and through it on the other parts of the machine. One by one these will give way, and have to be compensated in turn. If still neglected and left to take care of itself, there will come a time when so many sections are affected, that the remainder cannot overcome the mischief, and compensation will fail. The car will become practically useless. Perhaps, like the one-hoss shay, it will collapse en masse. It has gone beyond the stage of running badly, it has broken down.

The human machine.

The human system is much like a motor-car, in that it consists of a vast number of parts acting in unison. Yet it is infinitely more wonderful, for it is much more complicated, and can create its own supply of energy. It is made, roughly speaking, of a framework of bone and muscle, a delicately-adjusted alimentary system, whereby it takes in and assimilates food, and of a circulatory apparatus which drives blood and nourishment to all parts of the body. It contains also a nervous system, compared with which these other parts are crude, mechanical contrivances. For it is on their nervous supply that they depend for their usefulness. Cut the nerves that go to a limb, and the finest muscles in the world are as helpless as the meat in a butcher’s shop. Deprive the heart of its nerve supply for a single minute, and it will never beat again.