If the stew-pan be close shut, it is evident that none of the nutritive principles can escape, and must either be found in the meat itself or in the liquid. The water or gravy in which the meat is stewed, being capable of dissolving the gelatine and albumen, the greater part of them become separated during the simmering process. Now, since the firm texture of the bundles of fibres of the meat is owing to the solid gelatine and albumen glueing them, as it were, together, when they are dissolved and disengaged, the meat must become greatly disorganized. These principles, as well as the fat and osmazome, are partly disengaged from the meat, and become united with the gravy. It is to these, indeed, that the gravy owes all its richness and excellence. The muscular fibres and the tendons acquire a gluey appearance and texture, and the whole forms a savoury gelatinous _stew_, _gravy_, or _soup_. No scorching or browning of the meat takes place if the process is properly conducted; for the temperature to which it is exposed does not exceed the boiling point of water. In the stewing of vegetables, saccharine matter is formed, the starch and mucilage are rendered soluble, and of course, set free the woody fibre, which either floats through the liquid or adheres together very slightly. It accordingly constitutes either a pasty fluid, or converts the vegetables to a soft pulp; sometimes their original shape being preserved entire, and at other times not. BOILING. Boiling is a much more common operation than any of those we have considered, with the exception perhaps of roasting. It consists, as every body knows, in subjecting the materials of food to the influence of heat, through the medium of boiling water, or of steam. The water employed for boiling meat or pulse should be soft, and the joint should be put on the fire immersed in cold water, in order that the heat may gradually cause the whole mass to become boiled equally. If the piece of meat is of an unequal thickness, the thinner parts will be over-done before the more massy portion is sufficiently acted on by the boiling water. Salted meat requires to be very slowly boiled, or simmered only, for a quick and rapid ebullition renders salted provisions extremely hard. Frozen substances should be thoroughly thawed, and this is best effected by immersing them in cold water. Count Rumford has taken much pains to impress on the minds of those who exercise the culinary art, the following simple but pratical, important fact, namely, that when water begins only to be agitated by the heat of the fire, it is incapable of being made hotter, and that the violent ebullition is nothing more than an unprofitable dissipation of the water, in the form of steam, and a considerable waste of fuel.