But the greatest immediate practical benefit derived from the new knowledge of micro-organisms is the certainty with which some large groups of infectious disease can be controlled by private and public measures of sanitation.
Of course, in sanitation, as in other phases of morals, it is not as easy to do as to know what 'twere well to do. But it is safe to say that if we were ready in this country to follow such dictates of science in sanitary measures as are of known efficiency, we could secure their birthright of long life and health to a large proportion of that forty per cent of all the people who, as statistics show, are now destined to perish from preventable infectious maladies.
The means by which individuals and health boards may realize the possibilities for human weal so clearly indicated in the newly won lore of preventive medicine I need not here recount. They are easily enough learned as soon as the conviction of their importance has grown to a fixed purpose of action.
The scope of this address does not permit me to dwell upon the really wonderful degree of accuracy with which the educated and experienced physician of to-day can detect abnormal conditions in the varied cellular structures of the living body, nor upon the clear conception which he may acquire of morbid states and processes in situations physically inaccessible. He can recognize what groups of hidden cells are faltering in their work, are struggling under burdens, or in what way the co-ordinating mechanisms are failing in their tasks; and now in one way, now in another, and not most often with drugs, as so many think, can he tide the halting mechanism over its hour of stress. The cause of the disturbance may be removed, rest secured, pain assuaged, perverted function set right, and even for a time the aged, worn—out mechanism encouraged to prolong its task. And if the physician can not so frequently as we would wish guide to the happiest issue the healing forces over which the human frame has gained control, it is certain that, other things being equal, his success is assured just in proportion to his accurate practical knowledge of the delicate mechanism which he is seeking to repair, and his comprehension of the nature of the life forces which he must in the right way and at the right moment aid, and with which he must as certainly not unwisely interfere.
In these hurried glimpses of only a limited phase of medicine, it is most significant that there is no talk of humors and auras and vital spirits, nor of illusive and intangible fancies such as for centuries held sway in fields once ruled by demons and angry gods, but of definite things which we can see and handle and measure. Herein, to my thinking, lies the heart of our achievement and the brightest promise for the future.
