Few people have any just conception of the prevalence of disease even in their own midst——among their own kindred; and this is simply because it never absurdly happens that all those who are subject to illnesses are “attacked” at the same time. When any large proportion are down at once, the doctors call it an _epidemic_, and it is attributed to a “wave”——an epizootic or influenza wave, for example, according as the victims are horses or men (the poor animals depend upon the elevated race for their habits, and never have disease except these are unphysiological),——when, in fact, the so-called epidemic, whether it be scarlet or yellow fever, diphtheria, or what not, is the result chiefly of the uniformly bad living habits of our people and their consequent predisposition to sickness. I do not ignore the influence of contagion in certain disorders, but assert that no person in _prime physical condition_ is ever made sick by transient contact with the so-called contagious diseases. “There can be no doubt,” says Dr. Moore, “of the inherent effort of the system to preserve its integrity and to resist and overcome the effects of morbid influences. And when the system is properly organized and perfect in its physiological functions, it has the power to accomplish this (unless these obnoxious influences are so overwhelming as to destroy life at once) in a prompt and complete manner, unaided by any external influences whatsoever, so that health will be maintained and all injurious action of disease-producing causes unconsciously and successfully averted. But if instead of such a properly organized and healthy system, we have formed an incomplete and inferior grade of structural organization, and consequently an enervated nervous system, resulting from imperfect and deficient nutrition, such as evidently exists in the scorbutic diathesis (the effect of deficiency in vegetable food), or as must result from habitual or frequent digestive disturbances, this endeavor to resist or avert disease, will be necessarily so enfeebled that it will be impossible for the system, by its own inherent and unaided energy, either to ward off or to overcome the effects of disease-producing agents. This protective and restorative effort, if not sustained by a high character of structural organization and active nervous energy, must be followed, therefore, as a natural consequence, by an exhaustion of vital power; in which condition there would be evidently an increased susceptibility to all morbific influences, and a marked predisposition to any exciting causes of disease which might be brought to bear upon it.