In regard to an exclusive or almost exclusive vegetable diet for man, the universal experience has been that while it may keep him in apparent health for some time, it eventually results in a loss of strength and general resisting power against disease, which becomes evident after some months, if not before.

Of vegetarianism Bauer says: "The beneficial effects of vegetarianism certainly do not depend on the fact that its followers take no meat, and still more no animal food, but on their giving up their former bad habits".

No doubt much of the alleged benefit of vegetarianism is due to the greater freedom of action of the bowels, induced by the use of bran bread and other coarse articles of food.

It is impossible to subsist for any length of time on a diet which does not contain a considerable quantity of nitrogen, which constitutes so important an element in the composition of the great majority of structures of the body, and, in fact, of protoplasm itself.

Attempts have from time to time been made, for economic reasons, to furnish large bodies of labouring men, employed by contract or otherwise, with a purely vegetable diet; but this diet is found to defeat its own ends, in that the maximum of labour cannot be maintained by men who are fed exclusively on vegetable food, although some carbohydrates are essential. It gradually induces a condition of muscular weakness and languor with disinclination for either physical or mental work. In support of this statement Vigsford relates that for the construction of a railway from Paris to Rouen, English and French workmen were employed. The former did one third more work than the French, until in the French diet roast beef, as in the diet of the English, was substituted for bouille and soup, after which the work done by the two gangs of men was equalised.

In referring to graminivorous people, like the Bengalese, Chambers wrote: "If required, to exert themselves in any unusual way when food is deficient, they simply die. The reason is evident - they have been living on their own tissues, and the small quantity of albuminous matter in grain is a long time in building them up again, so that for weeks, or even months, their muscles are in a state of atrophy." It is found, too, that their food must be very gradually altered if they are to change to a mixed diet.

Animal food in some form must be regarded as absolutely essential for all vigorous races. When the diet of enthusiastic "vegetarians " is carefully investigated it is found that the strictly hydro-carbonaceous food is supplemented by such articles as milk, eggs, etc., which are used in cooking or in other ways, although the consumption of nitrogenous food may appear very much restricted.

It is believed by Gübler and others that an exclusive vegetable diet eventually develops an atheromatous condition of the arteries, on account of the large proportion of mineral salts which thus enter the blood, but the evidence of this is not convincing. It is also claimed that a vegetable diet favours the deposition of mineral salts in different parts of the body, as phosphatic stone, gravel, and the tartar on the teeth, and that living upon coarse cereals alone makes the skin rough, and the individual dull, heavy, and ill-tempered.

While it is quite true that some kinds of vegetables contain a large proportion of nitrogenous substance, it exists in a form in which it is less easily assimilated than animal proteid. In vegetable foods nitrogenous materials are more or less closely mingled with starch. Cellulose itself is often very tough and insoluble in the digestive fluids, so that as large a proportion of protein as 17 per cent may be wasted, while not over 3 per cent of the proteid of animal food remains undigested (Yeo). This is an important illustration of the fact that one must not be guided by chemical composition alone in selecting the proper dietary for man, but the question should rather depend upon the actual nutrient value of the food when absorbed. A food in its ultimate analysis may yield the necessary chemical ingredients for a nutritious diet, and yet from imperfect digestibility it may prove of little service for actual nutriment.

There are many facts in Nature in addition to those already discussed which indicate without doubt that man from his earliest prehistoric days has been omnivorous, adapting himself to his surroundings and eating, in his primitive condition, whatever his environment afforded, with least expenditure of labour to obtain it, now vegetable, now animal food. This is shown in the structure of the teeth in prehistoric skulls, and in the length of the alimentary canal and character of the digestive organs and secretions as at present existing.

The ancient Britons are known to have subsisted largely upon acorns, berries, roots, leaves, etc., but other primitive tribes ate fish, shellfish, and, when they could kill it, game.

A brief glance at the dietetic habits of the more primitive tribes of mankind at present living shows that no arguments can be drawn from them as to the advantages of any particular class of foods.

Many savage tribes to-day live very largely upon vegetable food, although an exclusive vegetable diet is almost unknown among them, and most of them eat meat whenever they can obtain it, or they supplement their food by nitrogenous articles, such as milk, eggs, fish, and insects of various kinds. Even the Chinese and Japanese, who subsist principally upon simple farinaceous food, such as rice, eat also eggs, fish, pork, and chicken. On the other hand, there are tribes of men inhabiting very hot countries who eat considerable quantities of meat, as, for example, the Nubian Arabs and Abyssinians. Some natives along the Congo subsist solely upon fruits (plantains) and insects. The Mongolian lives by his herds - upon milk products and meat - bread being scarcely known to him. The Australian savage is omnivorous, and, having no cereals, he subsists upon berries, beans, pith, nuts, honey, larvae, ants, etc. The Papuan Islanders live chiefly upon sago, fish, and fruits. The New Caledonians were formerly cannibals, but are now vegetarians by preference, and prefer to trade their pigs and goats with passing ships rather than to eat them.

Vegetarianism in former times has had many famous advocates. Shelley was a vegetarian, so was Jean Jacques Rousseau, and Goldsmith also at one time. There is a vegetarian society in England which has established restaurants in London, Manchester, and several other localities. In London there are upward of 4,000 members of this society. There is a similar organisation in this country. The creed of esoteric Buddhism has induced some persons in this country to adopt vegetarian habits, but few of them adhere to them strictly or for long.