Old age has been tritely described as a purely relative term; senility is to be recognized in many persons young in years and is often absent in those of late middle, or even of advanced age. There is no time in the life of a human being when this can be said definitely to begin. It is possible that if the undivided attention and energy of able thinkers were directed toward the means of combating these changes great gains could be made. Indeed notable progress has already been initiated and is being demonstrated with increasing rapidity in prolonging the age of the race through the one avenue of research which is really a development of the last decade. In laying the foundations of constitutional vigor by giving the chief attention to the disorders of children, their proper feeding and hygiene during the first few months of life, the foundation of longevity is capable of being firmly laid. Already there are abundant statistics to prove that the possibilities of retaining vigor to late age in civilized countries is being hopefully revolutionized. Too great praise can not be given to the researches of those men who, with insistent and prophetic voice, have demanded that the infant life shall have better opportunity afforded for prolongation by the regulation of diet and hygiene. If the foundations be well laid the problem of the superstructure can be made a matter of exact procedures. Not only are we of the medical profession becoming keenly alive to this great truth, but the gospel has filtered down and is being rapidly accepted by the great mass of thinkers. It matters little what is done, or what opportunities for growth and development are offered for the nation, if the infant child is neglected, even relatively, in the first three to six months of its life. No skill consistent with modern medicine is able to repair, except in the smallest degree, the irretrievable damage upon that human constitution which has not acquired a fair start in life. Two items of knowledge have been added to the subject of child growth by the clear teachings of such men as Jacobi and Rotch in insisting upon thorough attention to the details of food and nursery life during the period of babyhood. It is possible to find among the histories of those who have attained great age and retained their vigor beyond the ordinary span of life few instances of bottle-fed babies. In the future this will not be so, although at no time can we assume that the same degree of physical integrity can be acquired by artificial feeding as could have been by the natural methods of infant nourishment. Another fact comes up in the histories of very old people that they nearly all spent the earlier months and years of their lives outside of large centers of population.
It is a fact abundantly well known, and yet not of popular knowledge, that constitutional vigor is practically impossible except in the first generation in those who live in large centers without change. Statistics go to show, for London at least, that the fourth generation
