Food composed of animal and vegetable materials is, in truth, that which is best suited to the nature and condition of man. The proportions in which these should be used it is not easy to determine, but generally the quantity of vegetables should exceed that of animal food. “On this head,” says Dr. Fothergill, “I have only one short caution to give. Those who think it necessary to pay any attention to their health, at table, should take care that the quantity of bread, of meat, and of pudding, and of greens, should not compose, each of them, a meal, as if some only were thrown in to make weight, but carefully to observe that the sum of, altogether, do not exceed due bounds or incroach upon the first feeling of satiety.” All the products of the vegetable kingdom, used as aliment, are not equally nutritious. When we contemplate with a chemical eye the nutritive principles contained in vegetable substances, we soon perceive that they are but few in number, namely, starch, gluten, mucilage, jelly, fixed oil, sugar, and acids; and the different vegetable parts of them are nutritious, wholesome, and digestible, according to the nature and proportion of their principles contained in them. The starch and gluten appear the most nutritious, and together with mucilage at the same time, the most abundant ingredients contained in those vegetables from which man derives his subsistence. Hence, from time immemorial, and in all parts of the earth, man has used farinaceous seeds as part of his food, for they contain the above-mentioned materials in the greatest abundance. Of these the most nutritive are the seeds of the _Cerealia_, under which title are commonly comprehended the _Gramineæ_, or _Culminiferous_ plants. Whilst the seeds of the _Gramineæ_ supply the most important part of food furnished by the vegetable kingdom, in almost every part of the world, their leaves and young shoots support that class of animals hence called graminivorous, whose flesh is most generally eaten. These vegetables are distributed so universally over the face of the earth, and have become to such a degree the object of culture, that they are very generally made into bread, or are employed instead of it; and, upon the whole, it appears that they are nutritive merely in the proportion to the quantity of farinaceous matter contained in them; but this substance exists in different combinations in different cereal and leguminous seeds. It is combined with gluten in wheat, with a saccharine matter in oats, and in many leguminous seeds, such as Harricot beans and pease, and with viscous mucilage in rye and Windsor beans.