Nevertheless, the perception that the secret of individual health lies in fostering the resistant or protective elements, which should be present in normal blood, marks a great step in advance; for from it have originated measures to curtail the course of an illness and to reduce the risk of its recurrence. It is hardly Utopian to forecast, as Sir Almroth Wright has done, that the physician of the future will take upon himself a still higher rôle than he has hitherto assumed in this work of the prevention of ill-health, for he will attempt, by means of systematically strengthening individual capacity for resistance to disease, to remove the necessity for curing those who have fallen victims to its attacks. The gain in health, in happiness, in time and in money would be incalculable. For instance, had the death-rate _all_ over England during 1908 stood at 13.8 per thousand, instead of at favoured places only, no less than 33,831 lives would have been saved. Of these deaths, one-fifth were those of infants under twelve months old, the majority of them wholly preventable. What a reckless waste of racial and national capital; what an unnecessary cause of bitter sorrow and disappointment; what a source of unprofitable expenditure! The calculation has been made that for each death there are at least six cases of more or less serious illness, involving confinement to bed for a few days or a few weeks as the case may be. A simple multiplication sum will enable the reader to estimate the amount of serious illness represented by the total arrived at: the loss in time, health, happiness and efficiency is incalculable. The bright prospects for human health in the future, therefore, rely largely upon the use which will be made of this protective machinery, and the prospective gain to humanity lies in the hope that when family histories are kept systematically and the inherited tendencies of a child are far more accurately known, the invading forces of disease will never get a footing, because precautions to strengthen the body's own defensive powers will be taken as a matter of routine practice. The physiological balance being thus preserved from disturbance, the great fund of energy now utilised to resist encroachments will be available for productive purposes. So great a reformation cannot of course be brought about till shame is felt for the scandalously low standard of health now common among all classes, nor until a general determination is developed to remove the minor miseries from which we all suffer more or less impatiently. XIII. THE IMPORTANCE OF MENTAL HYGIENE IN FAMILY LIFE