from becoming more soft and pulpy, they will become dry and juiceless. If indeed the boiling point of the water be artificially increased above 212°, by pressure applied to the surface of the liquid, the fibres may be reduced to a pulp, quite homogeneous. When this is done by Papin’s digester, or by any other apparatus of the same kind, and when the process under such circumstances is long continued, the hardest bones may be converted into jelly. It is only by boiling that the more gelatinous parts of flesh can be completely extracted unaltered from such parts as are cartilaginous, ligamentous, or tendinous. COMPARISON OF THE CHEMICAL CHANGES PRODUCED ON ANIMAL AND VEGETABLE FOOD, IN THE DIFFERENT PROCESSES OF COOKERY. The principal operations of cookery which we have just examined and explained, all agree in this, that they effect some chemical change on the materials operated upon, by which they are rendered more digestible, more wholesome, and consequently more nutritive. In such of the operations as are performed by the direct application of heat to the flesh of animals, namely, roasting, baking, frying, and broiling, the meat loses the vapid and nauseous taste and odour which it possesses in a raw state, and becomes savoury, juicy, and grateful to the taste. These effects arise from the development of the gelatine and osmazome from the smaller vessels, and their being rendered soluble; while, at the same time a portion of the fat is liquified, and combines with them after they are disengaged. The fibres again, on the surface of the meat, are partly scorched, and form a crust, which, except in the interstices of the corrugations, is impermeable, and consequently prevents the savoury gravy that is disengaged from the fibres from oozing out or becoming evaporated. It is thus only disengaged from its chemical union with the fibres, and remains mechanically united with them in the meat, after it is cooked, as we see upon cutting into the fibrous portion. The effect produced on the fat is somewhat different. The direct application of fire to this portion of the meat soon melts part of the substance, and raises it to the boiling point, or nearly so; the water which it contains is consequently given off in the form of steam, and it carries with it a quantity of osmazome. It is this which occasions the peculiar odour that arises from meat while roasting.