We next arrive at the seeds, which are nutritious, from their amylaceous principle, viz. the cerealia. Of these we may mention rice, wheat, barley, oats, rye, Indian corn, millet, buck wheat, Guinea corn or sergo (holchus sorgum,l.in.),rote fescue grass(manna seeds), and the lotus of Africa, mentioned by Park. The fari-naceous roots of warm climates are more nourishing, viz. the sweet potato, the Jerusalem artichoke; the various yams, viz.dioscorea sativa, tryphilla, and bulbi-fera, the toyos and black cocao (arum colocausia and sagittifolium), the farina of the sweet and of the bitter cassada (iatropha manitot and ianipha), and the starch of the arrow root (maranta arundinacea). The Farina of the sweet cassada is the tapioca. We have placed the cerealia nearly in the order of their nutritious powers, for perfect accuracy is unnecessary; but we must now add, what is of more importance in a dietetic view, the order in which their saccharine principle is most readily evolved, and, of course, that in which they appear most acescent, viz. oats, barley, wheat, millet seed, rye, Indian corn, and buck wheat: the order of the others has not been ascertained.

After the arrow root we must mention the farinaceous fruits, and the farinaceous medulla: we know not that as nourishment they merit any distinction. Of the former kind we find the bread-fruit tree of the South-sea islands (artocarpus incisa Lin.), the bread nut (bro-simum alicastrum Lin.), the sweet chesnut, the plantain tree and banana fruit (musa paradisiaca & sapientum Lin.): of the latter the sago, the medulla of the sagus farinifera of Gartner; the cabbage-tree palm (areca oleracea ), and the meal bark (cycas coffra Lin.).

When with the farina a mixture of oil is discovered, the nutritious powers are more conspicuous; but the oil is sometimes so closely involved with the farina, as in the almond, the cashew nut, the filbert and walnut, that the stomach, except in its strongest state, is unable to separate it; while in the chocolate nut (the obroma cacao ), the cacao nut (cocos nucifera), and particularly in the butter cacao nut (cocos butyraceaj, it is so loosely combined as often to produce inconvenience. We must not, however, confound the butter cacao nut with the butter-nut oil described by Mungo Park; though, when expressed, it is the oleum calappi, the cow-nut butter. The tree noticed by Park is probably a species of the bassia Lin. The fat oils, viz. the oils combined with mucilage, may be still more nutritious, but they are not very digestible, and our experience with them is consequently limited.

The saccharine substances as nutriments are highly estimated, and perhaps their power is increased when joined with farina. We thus, therefore, place in the first rank, as least nutritious, refined sugar; it may be followed by coarser sugar, honey, maple sugar, beet-root sugar, and sugar of malt.

In this variety of vegetable bodies we must fix our eyes on the leading constituent parts. These, in a chemical view, we shall find to be mucilage and sugar, for starch differs only from mucilage, in containing a less proportion of caloric. Mucilage contains oxygen, hydrogen, carbone, and azote; sugar no azote, and a larger proportion of oxygen. We are yet too little acquainted with the influence of the chemical principles on the process of digestion, to be enabled to say how far one or the other of these principles may render a substance eligible as a nutrient from an examination of its analysis. We can perceive that oxygen is a necessary part of our system, as it gives a more brilliant hue to the red blood, and as our most recrementitious fluids are azotic. On the other hand, azote is necessary to animalise the vegetable portion of our food, and then becomes injurious. We can go no further in this path. From experience we find the herbaceous substances cold in the stomach, and affording so little support as to render the constitution unfit for great exertions, without at least some condiment, if not stronger nutriment. The cerealia give a better support, for reasons that we shall soon perceive: the farinaceous roots still more; but these also require assistance for their more perfect digestion: the oils and sugars, as we learn from Dr. Stark's experiments, will support the body for a time in tolerable health. The Irishman lives on potatoes, but he adds the stimulus of whiskey; the Spaniard and the Frenchman on bread, but with the assistance of olives and garlic. The infusion of oat-meal in Scotland, or the oat-cakes, require the warmth and animal impregnations of milk, if not of malt spirit; and the moss of Iceland would be an insalubrious food without the dried fish.

Yet in corn, in potatoes, in parsnips, and numerous other vegetable substances, particularly the grains, a principle, resembling that in animals, is found. It is styled the gluten, and resides in the skin of corn, and is more intimately mixed in the potato. In fact, the root of the latter consists of follicles containing farina, and the coats of these seem to contain gluten. The prevailing principle of gluten is azote, and, in each experiment, its chemical nature is animal. Mushrooms, which unite in a chemical and a dietetic view the vegetable and animal kingdoms, abound in gluten, and produce, on distillation, ammonia. We have, however, no experience of these as an article of diet; they are seldom employed but as a condiment. The various kinds used are the common mushroom (agaricus campestris Lin.), truffle (lycoperdon tuber Lin.), orange agaric (agaricus deli-ciosus Lin.), coral clavaria (cl. coraloides),the agricus mucheron, and the phallus mitra Lin.

We approach still nearer the animal kingdom in the various milks. These consist of an animal oil; of a co-agjjlable part, which is gluten; and sugar. Milk, on standing, absorbs oxygen, which promotes the separation of cream, and suffers an halitus to escape, which has not been examined, but which is certainly not an aqueous fluid only. The cream, with the oil, contains some gluten and sugar, and the latter are left in the butter-milk, after the operation of churning. This subject will be detailed more at length under the article Milk: the outline was only necessary to explain the dietetic properties of different milks. In diet, the milk of ruminant animals is chiefly employed, viz. cows', goats', and ewes' milk: this is the order of the nutritious properties, beginning, as usual, with the least nourishing. Cows' milk contains also the least, and ewes' milk the largest, proportion of cheese. Of the non-ruminant animals we employ women's milk, asses', and mares': they nearly resemble each other; but women's milk is the lightest, and perhaps contains most sugar. Later experiments seem to have shewn that it does not coagulate with vegetable acids. The coagulable part of milk, with more or less of the oil pressed into the form of cheese, will be afterwards considered.