"'Tis the art of eating which makes for years," says a sage proverb, and nothing can better promote this art for personal benefit than a sufficiently accurate knowledge of food elements, and their respective uses in the body. Broadly speaking, the sustenance on which we depend for the support of our lives comprehends animal and vegetable substances, besides our beverages. The more readily and thoroughly these substances are absorbed for supplying our physical needs, the better adapted are they for the purposes required. Residual matters are voided as excrementitious, the fact being, nevertheless, that the faeces passed by stool consist not simply of the remains of unabsorbed foods, but also to a considerable extent of superfluous digestive secretions, and the debris of intestinal linings. On a purely animal diet (of milk, eggs, and beef, or mutton) there is but little primary food-constituent (nitrogen) lost in the excrement; but when vegetable foods are mainly taken (carrots, potatoes, peas, and the like) the waste of nitrogen is very considerable, amounting, as, for instance, in the case of carrots, to nearly 40 per cent of the whole primary elements consumed.

The foodstuffs, again, which provide bodily warmth, and serve to fatten, are termed by chemists carbohydrates, containing twice as much hydrogen as oxygen; these include fruit-sugar, cane-sugar, milk-sugar, starch, and the same when made soluble by the saliva, being then known as dextrine; also cellulose, the basis of vegetable structures. Starch, and the sugars, are almost completely digested by a healthy person, and are sucked up into the blood nearly to the last particle; it being at the same time an important circumstance that a relatively larger amount of primary food-constituents is excreted by the bowels on a vegetable than on an animal diet. "Why these primary constituents of vegetable foods should be so much less completely absorbed than the other ingredients is difficult to say".

Human saliva is peculiarly rich in the ferment (diastase) which changes insoluble starches of foods into soluble dextrine, being richer apparently than the saliva of any other animal. The human stomach and the human brain are justly said to be the only analysts which never make mistakes.

It is on material food, comprising the particular constituents now discussed, reliance must be placed for supplying vital energy, and bodily health; nitrogen as primary nourishment, and carbon as fuel, being the chief elements. Nitrogen enters the body as such, and leaves it as waste urea; carbon enters the body as fat, starch, and sugar, leaving it in carbon dioxide. Gain or loss of nitrogen signifies gain or loss of flesh-tissues, whilst gain or loss of carbon signifies gain or loss of fatty deposits, and of bodily warmth. In dealing with weak or impaired digestions the cook can render valuable aid by carrying out as regards the food one or other of three distinct processes; each of these serves to commence the digestion of food by culinary skill before it is given to the invalid, so that the digestive powers are thus considerably economized: First, by malting, or pre-digesting the starches; secondly, by mixing with the meat foods and albuminoids some pepsin, or such ferment as converts these foods into soluble peptones; and, thirdly, by making an emulsion with sweetbread-juice of the fatty food which has to be digested after leaving the stomach, whilst within the first bowels.

"We may live without poetry, music, or art, We may live without eonseienee, and live without heart, We may live without friends, we may live without books; But civilized man cannot live without cooks".

Witty Mr. Punch has lately anticipated the substitution of clean, clever electricity for cooking, in place of black, smutty, clumsy kitchen coal, with its dust, and its difficulties of transport.

Then, instead of a hot, fiery task, disastrous to the temper, and comfort of the cook, it will be a recreative amusement for ladies to prepare the daily dinner.

"You need only turn a handle, and the soup is boiling hot, Appetising odours rising from the hospitable pot. Turn another, and the salmon in its mayonnaise lies fair; Press a button, and the mutton, with the currant jelly's there; Press again, and sweets, and entrees will at once appear in sight, And you'll fall to, on them all too, with a first-class appetite".

A diet of lean meat exclusively will build up the tissues, but if nothing else be taken, then the fat already stored up in the body will be fed upon, and consumed, so that the person will become thinner. Bismarck, by the advice of his physician, reduced his bulk in this way without any loss of energy, or any sense of illness. Again, we have to depend upon what we eat and drink for mental power, and intellectual capabilities. "So many factors," ays the Century Invalid Cookery Book, "enter into the make-up of a thought, that it cannot be said that any particular kind of food will ultimately produce a poem; but of this we may be sure, that the best work, the noblest thoughts, the most original ideas, will not come from a dyspeptic, underfed, or in any way ill-nourished individual." Swift, as a writer, was fully alive to this fact. "I wish you a merry Lent," quoth he, in a letter to Stella (March 5th, 1711). "I hate Lent I hate different diets, and furmity, and butter, and herb porridge, and sour devout faces of people who only put on religion for seven weeks." Not that a highly elaborate diet is essential for vigour of brain. "Hominis cibus utilissimus simplex," said Pliny authoritatively.

"Nam variae res Ut noceant homini credas. memor illius escae Quae simplex tibi sederit".

"For, divers meats do hurt; remember how When to one dish confined thou healthier was't than now".

Horace Walpole, writing from Norfolk (1743) to his friend John Chute, put the matter thus: "Indeed, my dear Sir, you certainly did not use to be stupid; and till you give me more substantial proof that you are so, I shall not believe it. As for your temperate diet, and milk, bringing about such a metamorphosis, I hold it impossible. I have such lamentable proofs every day before my eyes of the stupefying qualities of ale, beer, and wine, that I have contracted a most religious veneration for your spiritual nouriture. Only imagine that I here every day see men who are mountains of roast beef, and who only seem just roughly hewn out into the outlines of human form, like the great rock at Pratelino! I shudder when I see them brandish their knives in act to carve, and I look on them as savages that devour one another. I shouldn't stare at all more than I do if your Alderman at the lower end of the table was to stick his fork into his neighbour's jolly cheek, and cut a brave slice of brown and fat! Why, I swear I see no difference between a country gentleman and a sirloin; whenever the first laughs, or the second is cut, there run out just the same streams of gravy".