A vegetarian diet, with milk and a few eggs daily, is the best nourishment for old people; the greater the age the more of the latter should be taken. In fact, persons advanced in age will do well to eat very little meat, for reasons which are fully given in the chapter on the dangers of a too abundant meat diet. We have thus seen that a vegetarian diet can give the best results, not only in the prevention and cure of many diseases, but also in the preservation of health in old age. It is a fact that we often see persons who follow such a diet looking much fresher and more youthful than those who partake of much meat, especially when they have passed the seventies. But if milk and vegetarian diet, with a few eggs daily, can be taken for many years and yield good results, it is quite a different case with those people who are in the habit of living only on vegetables to the exclusion of any article of animal food; such are vegetarian fanatics, and if they keep up this deleterious habit for a lengthened period, they must inevitably suffer for it. Even if we do not admit the pretensions of certain authors, who declare that the albumin of the vegetable is less nourishing than the albumin of animals, still it is impossible for us to introduce into our bodies the quantity of vegetables which would contain the number of calories necessary in order that we should not suffer from a deficiency of them, and at the same time would allow for waste. To satisfy the requirements of our bodies we would have to eat enormous quantities of vegetables and thus overload the stomach and intestines, with the result that even the strongest stomach would undoubtedly give way after a certain time, and dyspepsia, especially sour stomach, and eventually atony, and in many cases even dilatation, of the stomach would follow; and abnormal fermentation would readily take place in the intestines after a certain time. Consider, also, what large amounts of enzymes, how much saliva, hydrochloric acid, bile, etc., must be produced in order to insure a good digestion and assimilation of the food, though it is of course true that the ferments, at least, can readily act in a very small degree upon large quantities of food. Vegetarian diet has also the drawback that, for reasons already mentioned, more salt must be taken when we partake of it. There are many people who develop hyperchlorhydria after a vegetarian diet, and we frequently had to have our patients abandon such a diet when they got acid stomachs; and they only recovered from these ill effects after animal food had been given in certain quantities. It is certain that the present capacity of the stomach and intestines, and their present anatomical and histological structure, also, is not sufficient or adequate for the continued use of a vegetarian diet, the greatest danger of which lies, however, in the threatening _under_-nutrition, and in consequence the imminent danger of bacterial infection.