The vegetable substances used for food are, if we include fruits, much more numerous than those derived from the animal kingdom. The chief of these, however, are the different sorts of grain and pulse, the _farina_ or flour of which, contains a large proportion of starch, gluten, and mucilage, and but little woody fibre, and is consequently highly nutritious, and easily digested. To this class of plants we are also indebted for the food of the animals whose flesh is most generally used. In pulse, as well as in rye and oats, there is, besides the principles just mentioned, a considerable portion of sugar, which adds to their nutritive qualities. We would class the different sorts of nuts, next to grain and pulse, in the proportion of nutriment which they afford; starch and mucilage are their chief elements, but these are combined with a kind of oil which is not of easy digestion, and makes them disagree with most people when too liberally used. Almonds, filberts, walnuts, and cocoa, are the nuts in most request. Chocolate is a preparation of this kind, which is very nutritious to those with whom it agrees. Next to grain, pulse, and nuts, we may place the farinaceous roots, potatoes, carrots, parsnips, and Jerusalem artichokes. Of these, the first, contains the most nourishment, which depends on the great proportion of starch with which it abounds. Other pot-herbs possess little nourishment. Cabbage and greens, for example, are chiefly composed of fibre, mucilage, and water, and the same is true of onions, leeks, celery, lettuce, and broccoli. Of fruits, those which are most farinaceous and mucilaginous, and which are sweet from the sugar contained in them, are the most nutritious. The pear should seem to answer this description the nearest, but experience proves that this fruit is of less easy digestion than the apple, whose greater acidity corrects the heavy quality of the saccharine matter with which the pear abounds. GENERAL OPERATIONS OF COOKERY. Few of the substances which we use for food are consumed in the state in which they are originally produced by nature. With the exception of some fruits and salads, all of them undergo some preparation. In most cases, indeed, this is indispensable; for, otherwise, they would not only be less wholesome and nutritive, but less digestible. The preceding observations, therefore, are only applicable to the materials when cooked, and not to the crude vegetables and raw flesh in the undressed state. The general processes of cookery resolve themselves into the various modes of applying heat under different circumstances. They are the following--roasting, frying, broiling, baking, stewing, and boiling. These operations not only soften the raw materials, and render them alimentary, but the chemical constitution of the cooked substance suffers also such alterations, that its constituent parts can often no longer be recognised. ROASTING ON A SPIT