In the cooking of vegetables, saccharine matter is often formed, or mucilage and jelly extracted; and the whole substance is on that account rendered more palatable, wholesome, and nourishing. These effects are very well exemplified in the changes which take place in flour when converted into bread;[24] which differs materially from flour paste, insomuch that the constituent parts of the unbaked dough can no longer be separated by the processes employed in chemical analysis. [24] A treatise on the _art_ of making good and _wholesome_ bread of wheat, oats, rye, barley, and other farinaceous grain, exhibiting the alimentary properties and chemical constitution of different kinds of bread corn, and of the various substitutes used for bread, in different parts of the world, p. 58, 1821. Vegetable substances are most commonly boiled or baked; or, if occasionly fried or roasted, there is always much water present, which prevents the greater action of the fire from penetrating below the surface. The universal effect of cookery by boiling upon vegetable substances, is to dissolve in the water some of their constituents, such as the mucilage and starch, and to render those that are not properly soluble, as the gluten and fibre, softer and more pulpy. COMPARATIVE DIMINUTION OF THE WEIGHT OF MEAT IN COOKING. It is evident, that whether the heat be applied directly or indirectly for cooking animal food, there must be a considerable diminution of weight. In the cooking of animal substances in public institutions, where the allowance of meat is generally weighed out in its raw state, and includes bones, and is served out cooked, and sometimes without bone, it is a matter of importance to ascertain nearly their relative proportions. Much, no doubt, depends upon the piece of the meat cooked, and the degree of cookery, and the attention bestowed on it. Persons who salt rounds of beef to sell by retail, after it is boiled, get 19 lbs. of cold boiled beef from 25 lbs. raw; but the meat is always rather underdone. Messrs. Donkin and Gamble boiled in steam 56 lbs. of captain’s salt beef; the meat, when cold, without the bones, which amounted to 5 lbs. 6 oz. weighed only 35 lbs. In another experiment, 113 lbs. of prime mess beef, gave 9 lbs. 10 oz. of bones, and 47 lbs. 8 oz. meat; and in a third, 213 lbs. mess beef gave 13 lbs. 8 oz. bones, and 103 lbs. 10 oz. meat; or, taken in the aggregate, 372 lbs. of salt beef, including bones, furnish, when boiled, 186 lbs. 2 oz., without bone, being about 50 _per cent._; or, disregarding the bone altogether, salt meat loses, by boiling, about 44.2 per cwt. or nearly half.