Ignorance is one of the root-causes of disease. Very often we get bewildered at the most ordinary diseases out of sheer ignorance, and in our anxiety to get better, we simply make matters worse. Our ignorance of the most elementary laws of health leads us to adopt wrong remedies or drives us into the hands of the veriest quacks. How strange (and yet how true) it is that we know much less about things near at hand than things at a distance. We know hardly anything of our own village, but we can give by rote the names of the rivers and mountains of England! We take so much trouble to learn the names of the stars in the sky, while we hardly think it worth while to know the things that are in our own homes! We never care a jot for the splendid pageantry of Nature before our very eyes, while we are so anxious to witness the [Pg 3] puerile mummeries of the theatre! And in the same way, we are not ashamed to be ignorant of the structure of our body, of the way in which the bones and muscles, grow, how the blood circulates and is rendered impure, how we are affected by evil thoughts and passions, how our mind travels over illimitable spaces and times while the body is at rest, and so on. There is nothing so closely connected with us as our body, but there is also nothing perhaps of which our ignorance is so profound, or our indifference so complete. It is the duty of every one of us to get over this indifference. Everyone should regard it as his bounden duty to know something of the fundamental facts concerning his body. This kind of instruction should indeed be made compulsory in our schools. At present, we know not how to deal with the most ordinary scalds and wounds; we are helpless if a thorn runs into our foot; we are beside ourselves with fright and dismay if we are bitten by an ordinary snake! Indeed, if we consider the depth of our ignorance in such matters, we shall have to hang down our heads in shame. To assert that the average man cannot be expected to know these things is simply absurd. The following pages are intended for such as are willing to learn. I do not pretend that the facts mentioned by me have not been said before. But my readers will [Pg 4] find here in a nutshell the substance of several books on the subject. I have arrived at my conclusions after studying these books, and after a series of careful experiments. Moreover, those who are new to this subject will also be saved the risk of being confounded by the conflicting views held by writers of such books. One writer says for instance, that hot water is to be used under certain circumstances, while another writer says that, exactly under the same circumstances, cold water is to be used. Conflicting views of this kind have been carefully considered by me, so that my readers may rest assured of the reliability of my own views.