_Ghee_, the East-Indian form of butter, is simply fresh butter clarified by melting, and is used as a dressing for the meal of rice. Butter, though counted as a pure fat, is in reality made up of at least six fatty principles, there being sixty-eight per cent of margarine and thirty per cent of oleine, the remainder being volatile compounds of fatty acids. In the best specimens of butter there is a slight amount of caseine, not over five per cent at most, though in poor there is much more. It is the only fat which may be constantly eaten without harm to the stomach, though if not perfectly good it becomes an irritant. The _Drippings_ of roasted meat, more especially of beef, rank next in value; and _Lard_ comes last on the list, its excessive use being a serious evil. Eaten constantly, as in pastry or the New-England doughnut, it is not only indigestible, but becomes the source of forms of scrofulous disease. It is often a convenient substitute for butter, but if it must be used, would better be in connection with the harmless fat. Eggs come last; and as a young animal is developed from them, it follows that they contain all that is necessary for animal life, though in the case of the chicken the shell also is used, all the earthy matter being absorbed. In a hundred parts are found fourteen of nitrogen, ten and a half of fatty matter, one and a half of saline matter, and seventy-four of water. Of this water the largest part is contained in the white, which is almost pure albumen, each particle of albumen being enclosed in very thin-walled cells; it is the breaking of these cells and the admission of air that enables one to beat the white of egg to a stiff froth. The fat is accumulated in the yolk, often amounting to thirty per cent. Raw and lightly-boiled eggs are easy of digestion, but hard-boiled ones decidedly not so. An egg loses its freshness within a day or so. The shell is porous; and the always-feeding and destroying oxygen of the air quickly gains admission, causing a gradual decomposition. To preserve them, they must be coated with lard or gum, or packed in either salt or oats, points down. In this way they keep good a long time, and while hardly desirable to eat as boiled eggs, answer for many purposes in cooking. CHAPTER XI. THE CHEMISTRY OF VEGETABLE FOOD. We come now to the vegetable kingdom, the principal points that we are to consider arranging themselves somewhat as follows:-- Farinaceous seeds, Oleaginous seeds, Leguminous seeds, Tubers and roots, Herbaceous articles, Fruits, Saccharine and farinaceous preparations.