d 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
extraordin