It is not possible, much less desirable, that the whole population should plunge into amateur studies of recent physiological advance, nor even that it should dabble, as its units are too much disposed to do, in pseudo-scientific pathological publications. But it is both possible and desirable for all who assume the direction of their own lives or those of children to “read, mark, learn, and inwardly digest” some fruits of the labours of others in the garden of health.
Were there one fixed standard of health to which all could attain, the practice of hygiene would be attended by a charming simplicity. Unfortunately, modern science forces us to conclude that each individual can only reach his own particular standard of well-being. The grades of health are consequently infinite in number, and the task which devolves on parents and guardians to secure that the standard possible to each child under their care be attained is no light one. So general is the blindness to these truths, that the degree of health enjoyed is in most cases far below the possible standard; the results of ancestral vice, of parental ignorance, or of defective environment having sapped prematurely the springs of progressive potentiality.[116] The mental and physical balance is thus rendered 257 relatively less stable and the powers of resistance to adverse conditions are diminished.
Happily, by virtue of its inherent power, but strictly in proportion to the vigour of this power, an organism is usually able to strike a new balance; for the capacity to regain its equilibrium is exquisitely delicate in human nature, if the change be neither too sudden nor too severe. Throughout life this process of self-adaptation to the presence of morbid influences is constantly exercising its protective power. If, however, the effort to overcome disadvantageous conditions be very great or much prolonged, the life of the individual is never quite so vigorous and symmetrical as it might and should have been. In a luminous address, delivered at the University of Leeds some few months ago,[117] Lord Justice Fletcher Moulton instituted a comparison between the human organism, which invariably tends to swing back to the normal whenever the balance of health is disturbed, and a ship which has safely weathered a stormy voyage. The ship, he writes, “is not stable, if stability means that she can defy the forces that bear on her to move her from her normal upright position, for ... the slightest roll of the sea ... will make her heel over. But she is stable, because when made to lean over, there is thereby generated a system of forces tending to return her to her place, which grows 258 greater the greater is the displacement, and thus ultimately becomes sufficient to overpower the disturbing forces.... As the ship arrives safely, her construction must be such that disturbances tend to right themselves when stability is seriously endangered. Some corresponding righting force also tends to bring back an organism to its normal state.”
The caution may not be amiss that the amplitude of the swing of a human pendulum, as well as the accuracy of its final balance, depends not only upon inherited nature and the amount of reserve force possessed, but will be stable or feeble, durable or transient, according to the influence of environment.
In what way, it will be asked, can individual capacity for health be gauged? to what degree can the power to progress or to resist encroachments be strengthened? at what age is intelligent supervision most important?
No concise and conclusive answers can be given to these most natural inquiries, but much light has been recently thrown upon the long duration of immaturity and associated instability in mankind; upon the power of self-protection inherent in the body;[118] upon the influence thereon of its environment; upon the penetrating power of heredity; and upon the urgent importance of the adolescent period.
Further, it appears that the healthful body is equipped to withstand the attack of the bacteria of most diseases, though the mechanism of self-defence is of more kinds than one. Of the different pathological bacteria identified up to the present, for instance, some appear to be eminently sensible to one kind of action of normal blood fluids, while they are in a much less measure sensible, or are, perhaps, entirely insensible to others; a complication which enhances our respectful admiration for the marvellous and intricate system which provides for our bodily welfare. Obviously, human nature would be practically immune from disease if this protective machinery were always in good working order: unfortunately this is not invariably the case—hence disease. It is the duty of hygiene to insure constant physical equilibrium, but the intricate tactics of Nature are as yet so imperfectly understood that man is not yet an ally of great worth in her operations.
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 260 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 261 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.