CONTENTS
| I. | The Body-Republic and its Defense | [1] |
| II. | Our Legacy of Health: the Power of Heredity in the Prevention of Disease | [31] |
| III. | The Physiognomy of Disease: what a Doctor can tell from Appearances | [55] |
| IV. | Colds and how to catch Them | [83] |
| V. | Adenoids, or Mouth-Breathing: their Cause and their Consequences | [103] |
| VI. | Tuberculosis, a Scotched Snake. I | [123] |
| VII. | Tuberculosis, a Scotched Snake. II | [140] |
| VIII. | The Unchecked Great Scourge: Pneumonia | [174] |
| IX. | The Natural History of Typhoid Fever | [198] |
| X. | Diphtheria: the Modern Moloch | [222] |
| XI. | The Herods of Our Day: Scarlet Fever, Measles, and Whooping-Cough | [243] |
| XII. | Appendicitis, or Nature's Remnant Sale | [267] |
| XIII. | Malaria: the Pestilence that walketh in Darkness; the greatest Foe of the Pioneer | [289] |
| XIV. | Rheumatism: what it Is, and particularly what it Isn't | [311] |
| XV. | Germ-Foes that follow the Knife, or Death under the Finger-Nail | [331] |
| XVI. | Cancer, or Treason in the Body-State | [350] |
| XVII. | Headache: the most useful Pain in the World | [367] |
| XVIII. | Nerves and Nervousness | [387] |
| XIX. | Mental Influence in Disease, or how the Mind affects the Body | [411] |
| Index | [439] |
PREVENTABLE DISEASES
CHAPTER I
THE BODY-REPUBLIC AND ITS DEFENSE
The human body as a mechanism is far from perfect. It can be beaten or surpassed at almost every point by some product of the machine-shop or some animal. It does almost nothing perfectly or with absolute precision. As Huxley most unexpectedly remarked a score of years ago, "If a manufacturer of optical instruments were to hand us for laboratory use an instrument so full of defects and imperfections as the human eye, we should promptly decline to accept it and return it to him. But," as he went on to say, "while the eye is inaccurate as a microscope, imperfect as a telescope, crude as a photographic camera, it is all of these in one." In other words, like the body, while it does nothing accurately and perfectly, it does a dozen different things well enough for practical purposes. It has the crowning merit, which overbalances all these minor defects, of being able to adapt itself to almost every conceivable change of circumstances.
This is the keynote of the surviving power of the human species. It is not enough that the body should be prepared to do good work under ordinary conditions, but it must be capable, if needs be, of meeting extraordinary ones. It is not enough for the body to be able to take care of itself, and preserve a fair degree of efficiency in health, under what might be termed favorable or average circumstances, but it must also be prepared to protect itself and regain its balance in disease.