Animal chemistry is in a very backward condition, as compared with vegetable and mineral chemistry. Prof. Bloxam, for instance, tells us that the chemical formulae of a great many animal substances are perfectly unintelligible, conveying not the least information as to the position in which the compound stands with respect to other sub-stances, or the changes which it might undergo under given circumstances. Certain results, however, have been obtained, and will be here cited so far as they have significance in the operations of cooking, no pretension being made to originality, and the authorities being cited in each case.

For the general guidance of the cook, meat may be said to be composed of four elements, namely: muscular fibre, albumen, fat, and juice - the latter being, chemically speaking, a very complicated substance containing a number of proximate elements.

"In the juice of flesh," says Prof. Bloxam ("Chemistry Inorganic and Organic," London, 1883)," which may be squeezed out of chopped flesh, there are certain substances which appear to play a very important part in nutrition. The liquid is distinctly acid, which is remarkable when the alkaline character of the blood is considered, and contains phosphoric, lactic, and butyric acid, together with kreatine, inosite, and saline matters."

These names will convey little to simple minds, but the essential point to be remembered is that the juice of flesh contains a variety of nutritive substances.

Flint, in his "Physiology of Man" (N. Y., 1875), says: "Food contains many substances having an important influence on nutrition which have never been isolated and analyzed, but which render it agreeable, and give to the diet that variety which the system imperatively demands.

"Many of these principles are developed in the process of cooking."

The same authority tells us that the effect of cooking on muscular tissue is to disinte- grate, to a certain extent, the intermuscular alveolar or connective tissue, and so to facilitate the action of the digestive fluids.

"The savors developed in this process have a decidedly favorable influence on the secretion of the gastric juice."

To present the same fact in another light: "All methods of preparation," says Payen ("Substances Alimentaires"), "which tend to render meat easier to divide or more tender, and often more agreeable to the taste, concur to increase its digestibility, or, in other words, its easy assimilation, and often annihilate certain causes of unhealthiness existing in raw meaty Fat and fatty substances are not digested in the stomach, inasmuch as the gastric juice has no action on them, further than setting them free from the albuminoid substances with which they may be entangled. This variety of food, together with the starch, is digested below the stomach, through the action of the pancreatic and intestinal juices. This explains why the saturation of food in general by fat during the process of cooking should be avoided, as the fat in this case acts as a varnish to the albuminous substances and prevents free access to the latter of the gastric juices, by which alone this class of food can be digested.

Albumen is a substance which becomes more indigestible the longer it is cooked; it is most easily digested in the raw state. The most familiar form of albumen is white of egg, which contains of albumen about 12 per per cent of water about 86 per cent., and about 2 per cent of soluble salts. 2