The proper study of mankind is what to eat and how to eat it. This is not precisely what Pope said, but the sentence as written is nevertheless correct.

We eat to live, and what we digest is of more consequence than what we eat. The Bible says, "The life of the flesh is in the blood." Good blood cannot be made without good digestion. Therefore the question of wholesome food and careful feeding is of the highest consequence to persons of all ages, but vitally so to those who have reached the period at which old age is commonly supposed to begin.

While the misuse of foods seems to be on the increase in the United States, we are told that the science of foods and eating has of late years been considerably advanced through researches made not merely into the compositions of foods, but also concerning the amount of food required to produce a given amount of energy and working power.

The wisest and oldest physicians in this country are vigorously preaching the gospel of common sense in its relation to eating and drinking. The chapters in this volume which have to do with "How to Live the Simple Life," "The Conservation of Energy in those of Advancing Tears," and so on, sharply suggest the practical character of the work being done by these apostles of right living to advance the general health and well being of the people.

The digestive organs make up the most wonderful of all wonder-working machines. The stomach, in particular, is remarkable in its construction. It has a hard task to perform and is long-suffering. But there is a limit to its endurance of abuse. The common stomach complaint which causes so much anxiety and distress is not a disease. It is only a loud cry against loading it to its fullest capacity with ill-assorted and poorly masticated foods. It has been said that three-fourths of all the poor health in the world is due, directly or indirectly, to the failure of the digestive organs properly to dispose of the food eaten.

Mr. George P. Brett, President of the Macmillan Company, New York, says: "Indeed so great are these evils of over-feeding and especially the over-indulgence in our modem city life that I have heard an educated and illustrious foreigner, who frequently visits our country, refer to it as the land of carrion and cathartics."

My own experience in this matter may be of some value to others. For a long time I was tormented by what seemed to be stomach indigestion. I used box after box of digestive remedies purchased at drugstores, but relief was only partial, and I kept on eating various foods without an intelligent understanding of their proper relation to each other, or how digestion of different kinds of food was accomplished, and of course the distress was not permanently removed. Finally I consulted my physician, Walter Kempster, M.D., who pronounced my ailment intestinal indigestion. He explained the matter to me, prescribed a simple remedy, and told me to beware of foods which contained a large proportion of starch.

This incident was one of the important turning points in my life. I began to read up on foods and digestion. Special attention was given to age in its relation to diet. My mode of eating and drinking was greatly changed. The regimen was simplified and mastication was thorough. Meats were excluded from my dietary, and drinking during meals was abandoned. And from that time to the present there has not been the slightest recurrence of indigestion in any form.

Sir Thomas Lauder Brunton, the eminent British physiologist, once asked: "Why has America the best dentists?" He answered the question himself by saying: "Because it has the best roller mills; and the better the mills the finer the flour; and the finer the flour the worse the teeth. Hence, the best dentists." And someone suggests that Sir Thomas may have truthfully added: "And finer the flour the more dyspeptics." But it is not so much the fineness of the flour that causes the trouble, as its misuse.

The question of food and digestion as they relate to people of advancing years is of supreme importance. From the many persons named in this volume, and also from the careful investigations by physiologists and scientists in America and Great Britain, it is absolutely certain that while a good supply of food is es sential during the period of growth and middle life, a diminished supply, as Sir Henry Thompson says, is desirable in relation to health and prolongation of life during the declining years when physical exertion is small, and the digestive faculty sometimes becomes less powerful also. The system of supporting aged persons, as it is termed, with increased quantities of food and stimulants, is an error of cardinal importance. The elderly man who desires to preserve fair health and to attain to longevity should gradually diminish his use of strong nitrogenous and much fatty food.

It may be best to remark right here, that Hutchinson, and other able physiologists, say that women require less food than men, for their bodies are not only as a rule of less weight, but are relatively richer in fat and poorer in muscle than those of men.

We, who are facing the setting sun, need to know more fully concerning the influence of various forms of food on growth and recuperative powers. We ought to be practical in the choice of foods, never fussy nor over-nice. Our appetites, providing they have no bad propensities, should guide us in the matter of eating. There is plenty of time before us so that we can afford to let the teeth and mouth do their full share of the digestive work. And unless we are equipped with good digestive powers and appetites which will not get the better of our judgment, there is danger of over-feeding. Sidney Smith once wrote to Lord Murray: "If you wish anything like happiness in the fifth act of life, eat and drink about one-half of what you could eat and drink"; and this creed is well worth taking into our lives.