wer continued far into old age are always lessons in plainness of
diet and temperance. One such temperate man will do as much work as ten
who are luxurious eaters, tipplers, and smokers. Diet for mental
workers should be light and easily digested, with a preponderance of
proteid food (_see_ Diet). Rich, tough and fatty foods, and hot
stimulating drinks should be avoided. As mental work is generally
sedentary work, and consequently having a constipating tendency, some
of the vegetable foods giving a stimulus to the muscles of the
intestines should form a part of the diet, such as green vegetables,
fruits, and oatmeal.

Food in Health.--As will be seen from many of these articles, the
question of diet is one of the greatest importance, in health as well
as in disease. The onset of disease is, in fact, often due to
long-continued abuse of the whole digestive system through the use of
unsuitable food. By unsuitable food, we mean not so much food that is
bad in itself, but rather that which is not suited to the temperament
or work of the eater, or to the climate and circumstances in which he
finds himself. A ploughman or fisherman, for example, may thrive on
diet which will inevitably produce disease in the system of one whose
work confines him to the house for the most of his time. One condition
of a healthy life is, therefore, careful consideration of our work and
circumstances before deciding on our diet. Also, a man of excitable and
irritable temperament will need different diet from one of a slow and
quiet nature. The food which will only stimulate the latter will
over-excite the former, and may even make him quite ill. What is
commonly called bad temper is often only the result of wrong diet, and
will disappear under a milder course of food. It will, of course, be
seen at once from this, that the case of every man must be considered
by itself. A decision as to proper diet can therefore only be made when
all the facts about a case are known, and in this matter the man
himself must decide a good deal for himself; nevertheless some general
directions can be given which will help our readers to a decision in
their own case.

In the first place, we would guard against a very common error--viz.,
that a smaller quantity of food, _chemically_ of a less nutritive kind,
means less nourishment to the body. On this head we refer to the
articles on Digestion and Assimilation. It may only be remarked here
that what the _body act