25 parts, it is obvious that oysters must be less nutritive than butcher's meat." Of the proteinaceous principle, the milk of different animals contains from 1.52 to 4.50 per cent. Of the gelatinous principle, or matter which may be transformed into gelatin, bones contain from about 17 to 27 per cent., and fish, flesh, and fowl from 5 to 7 per cent. The oleaginous principle almost entirely constitutes animal fats; the various kinds of milk contain from 11 to 4.20 per cent. The yelk of egg 28.75 per cent. Of the saline principles, which are very numerous in animal food, we have no accurate data, in fact their proportions are frequently too small to admit of being determined by our present methods of analysis. The elementary constitution of animal as compared with vegetable food, is much more closely allied to that of the blood and solids, for the nourishment of which it is intended. The ultimate composition of flesh is identical with that of blood, and while the alimentary principles occur in a much more concentrated state, than for the most part they do in vegetables, the different kinds of animal food exhibit among themselves less variety of constitution.

2. Vegetable foods are arranged after Tiedemann, partly by the method of natural history, and partly by the organs employed. There are two primary classes: 1, Aliments derived from flowering plants; 11, Aliments derived from flowerless plants. The first class has seven orders according to the parts used as food, seeds, fruits, leaves, &c. The orders of the second class are botanical, viz., ferns, lichens, algæ, and fungi.

The present chapter contains such a vast mass of detail, including numerous chemical analyses, that we can only undertake to give a general view of it, with an occasional allusion to principles available in dietetics. The first class of vegetables is by far the most important. Order A, comprises the seeds, among which the cereal grains contain an abundance of the vegetable nitrogenized materials, identical in composition with those of animal bodies, but diluted-so to speak-largely, with non-nitrogenized constituents. The proximate principles of these grains are starch; vegetable albumen; v. fibrin, gluten, and mucin, and oily matter, constituting raw or ordinary gluten; also, sugar; gum; earthy phosphates; ligneous matter in the form of bran, husks, &c.; and water. But of these, the different species and the varieties of each species of grain furnish very different proportions. Taking protein and its compounds as a standard, wheat is the most nutritious; oats, according to Boussingault's analysis, are nearly equivalent, then come rye and barley. Rice contains only from 3 to 4 per cent. of any proteinized principle, and above 80 per cent. of starch;-and maize, another most important source of human sustenance, appears to contain 5 or 6 per cent. of the former, to about 80 of the latter, with a considerable quantity of oil, and some gum and sugar. The various kinds of bread in general use by mankind are made of these cereal grains. Next in importance are the leguminous seeds, of which, chiefly, peas and beans are used in this country, containing from 10 to 14 or 15 per cent. of vegetable casein, a little gum and albumen, but no oil. The oily seeds, as the almond, walnut, &c., are composed of a large proportion of fixed oil; the former, according to Boullay's analysis, of 54 per cent. Thus the seeds of plants furnish an abundance of all the staminal principles of Dr. Prout;

they were among the most primitive materials employed, and still constitute the largest portion of the food of mankind. Their greatest deficiency is in the organic acids.

Ord. B. Of the fleshy fruits of the earth, a vast variety are eaten, and many are important articles of diet. None contain more than the most minute quantity of nitrogenized matter. Water forms the greater part of all, but its proportion lessens, and the quantity of solid matter increases as they become ripe; being in the drupaceous fruits from 70 to 90 per cent. Cucurbitaceous fruits are the most watery, the cucumber containing 97.14, and the melon 98.5 per cent. Gum, pectin, sugar, and the acids also enter into their constitution. When ripe, the quantity of sugar is in general greatly augmented:-in the cherry, for instance, from 1.11 to 18-12 per cent. The acids are chiefly the citric, tartaric, and malic; occurring free, or in combination with bases. Fruits contain also volatile oils, colouring matters, lignin, and particular extractives; and each fruit has in general some peculiarity in its composition, upon which its sensible and some of its dietetical qualities depend. Dates constitute a considerable portion of the food of many of the inhabitants of Egypt, Arabia, and Persia; according to a recent analysis by Reinsch, they are composed of more than half sugar, with pectin, pectinaceous gum, bassorin, fatty oil, and wax, but no nitrogenized principle; so that the chief nutritive material would appear to be sugar. The fig, which is eaten so much as food in eastern countries, also contains 62.5 per cent. of granular sugar. The olive, grape, oranges, lemons, pineapple, mulberries, strawberries, raspberries, and many others, are separately treated of;-space will not admit of any detail respecting them.

Order c consists of roots, subterraneous stems, and tubers; including the turnip, carrot, parsnip, beet, potato, and Jerusalem artichoke. The turnip contains 92.5 parts of water to 7.5 parts of solid matter, and a minute quantity of two nitrogenized substances,-v. albumen, and v. fibrin; but the most important substance in this order is, undoubtedly, the potato; its constituents being water, starchy matter, ligneous matter, v. fibrin, v. albumen, and gluten, oil, gum, asparagin, extractive, vegetable acids, salts, and occasionally, solanina. According to Einhoff, its acid is the tartaric combined with potassa and lime, but by Vauquelin it is regarded as the citric,-partly free and partly in combination with those bases in its raw state it contains from about 66 to 75 per cent. of

water.

The remaining orders include:-Or. D, buds and young shoots; as the onion tribe and asparagus, the former containing an acid vegetable oil, and the latter asparagin, a peculiar nitrogenized compound, regarded by Liebig as a nutritive agent:-Or. E, leaves and leafstalks; as the the cabbage, cauliflower, brocoli, watercress, lettuce, rhubarb, turniptops, spinage, &c., the green colour depending upon chlorophyle, a substance in the form of globules, in nature between resin and fat, and but little acted on by the digestive organs :-Or. F, receptacles and bracts; the artichoke, which contains a saccharine and mucilaginous juice, with starchy matter, being the only individual mentioned :Or. G, stems; furnishing farinaceous substances, as sago.

The second class of vegetables comprises-a few tuberous roots or rhizomes, used only in times of scarcity;-certain lichens, which owe

their alimentary qualities to a starchy matter usually accompanied with a bitter principle,—hence they require to be prepared before they are employed for food. Some are eaten by the hunters in the arctic regions under the name of "Tripe de Roche." Also certain species of algæ, which abound in mucilaginous or vegeto-gelatinous substances, to which they owe their dietetical uses; they also contain starch, and sometimes sugar. Carrageen, or Irish moss, is an example, the carrageenin being more nearly allied to pectin than to any other vegetable principle. Of the last order-fungi-three species only are used as food in this country, while in Russia they employ thirty-three species. The supposed alimentary principle of mushrooms is fungin, a substance allied to lignin, but, according to Braconnot, highly nitrogenized, although Vauquelin obtained from it little nitrogen, and Müller considers fungin to be one of the more simple nutritive substances.

3. Liquid aliments or drinks. The compounded liquid aliments are arranged in six orders. Or. A, Mucilaginous, farinaceous, or saccharine drinks; called "slops" in this country, and "tisans" on the continent. They differ but little from common water, have slight nutritive powers depending upon gum, sugar, &c., held in solution, and are employed as diluents and demulcents. Or. B, Aromatic or astringent drinks. This includes tea, coffee, chicory, chocolate, and cocoa. Tea contains 12 to 18 per cent. of tannic acid, also volatile oil, gum, albumen, resin, &c., and theine, (c. 8, h. 5, n. 2, o. 2,) a salifiable base, existing in combination with a part of the tannic acid. Hot water extracts the tannate of theine and also the tannin, but in cooling both substances precipitate. Theine, with the elements of water, and an excess of oxygen, is equivalent in composition to taurine. Liebig has accordingly suggested that tea may have some direct influence over the formation of bile; and that in sedentary persons, who take little azotized food, and in whom there is little waste of matter, tea may benefit the health by furnishing materials to form bile. The flavour of tea and its influence on the nervous system depend on its volatile oil. Coffee contains theine and several peculiar principles, as caffeic acid, upon which, probably, its odour depends. Like tea, it diminishes the disposition to sleep. The infusion or decoction of chicory forms a perfectly wholesome beverage. Chocolate kernels, or cocoa seeds, differ exceedingly from the last-mentioned substances, they contain 53 10 per cent. of oil, and 16.7 per cent. of albumen, with starch, mucilage, and lignin; also theobromine, (c. 9, h. 5, n. 3, o. 2,) which, from its analogy to theine, Liebig suggests, on hypothetical grounds, may contribute to the formation of bile and urine. Cocoa is somewhat less oily than chocolate, and rather astringent; when properly made it is freed from much of its oil.

Or. c, Acidulous drinks. They consist of water as a basis, and, usually, of a vegetable acid; being prepared with the juice of fruits, or by dissolving acids or acidulous salts in water, or by the decoction of fruits; as lemonade, imperial, and apple tea, respectively. Both the acid and water contribute to allay thirst. In this order are arranged carbonated or effervescent drinks, as soda water, &c. Or. D, Drinks containing gelatin and osmazome. These are essentially decoctions of meat, but frequently contain vegetables. By the agency of water and heat in

making broths and soups-bones, aponeuroses, cellular tissue and tendons yield gelatin; fatty matters are melted and diffused; and various products are obtained by unknown reactions.-a. Creatine, a nitrogenized crystallizable substance. b. Osmazome, the extractive upon which the odour and flavour chiefly depend. c. Ammonia. d. A sulphuretted compound. e. A volatile acid, analogous to acetic acid. f. An odorous volatile acid, similar to butyric acid. The last three being wholly or partially volatilized. The vegetables employed communicate colouring, mucilaginous, saccharine, azotized, and sometimes sulphuretted matters, with volatile oils and salts. The amount of nutritive matter in broth does not exceed 3.5 per cent. Beef-tea, mutton, veal, and chicken broths, are the lightest forms of animal food. Or. E, Emulsive or milky drinks. These hold in suspension an oily substance in a finely divided state. Almond milk contains in solution, casein, sugar, and gum; and retains in suspension a fixed oil; agreeing in many of its properties with animal milk.

Or. F, Alcoholic and other intoxicating drinks. The amount of spirit contained in beer (according to Brande, as given in a table at p. 158), is from 1.28 to 8.88 per cent., and the extract yielded, or its fixed nutritive constituents, are starch, sugar, dextrine, lactic acid, salts, the extractive and aromatic parts of the hop, gluten, and fatty matters; but the quantities are subject to great variation. An imperial pint of good porter gives about an ounce and a half of extract. Dr. Pereira thus proceeds:

"Considered dietetically, beer possesses a threefold property: it quenches thirst; it stimulates, cheers, and, if taken in sufficient quantity, intoxicates; and, lastly, it nourishes or strengthens. Its power of appeasing thirst depends on the aqueous ingredient which it contains, assisted somewhat by its acidulous constituent. Its stimulating, cheering, or intoxicating power is derived either wholly or principally from the alcohol which it contains. Lastly, its nutritive or strengthening quality is derived from the sugar, dextrine, and other substances contained in the extract. Moreover, the bitter principle of hops confers on beer tonic properties.

"From these combined qualities beer proves a refreshing and salubrious drink (always presuming that it is used in moderation), and an agreeable and valuable stimulus and support to those who have to undergo much bodily fatigue. When Dr. Franklin asserted that a penny loaf and a pint of water yielded more nourishment than a pint of beer, it is obvious that he regarded beer merely as a nutriment, and overlooked its stimulating and cheering qualities, of which bread and water are totally devoid." (pp. 415-16.)

Strong ales are richer in alcohol, sugar, and gum, than any other kind of malt liquor.

The term wine includes the fermented juice of fruits and saccharine fluids generally, but in a dietetical point of view, liquids obtained by the vinous fermentation of the juice of the grape are most important. The bouquet, or perfume of wine, seems to be an ether (œnanthic), formed by the action of an organic acid on alcohol, during fermentation. All wines are more or less acidulous, from the presence of acetic, carbonic, tannic, tartaric, and probably malic and other acids; but they vary much in this respect. Liebig is quoted, to the effect, that those wines which have most acid have most perfume; and that the acid and characteristic perfumes have some intimate connexion, since they are always found together.

Yet, a few pages onward, we are told that Johannisberger, possessed of a very choice flavour and perfume, is characterized by an almost total want of acidity. Bitartrate of potassa is the most important saline constituent, to which is frequently added tartrate of lime, and tartrate of alumina and potassa. The quantity of alcohol contained in wines varies greatly— from 12 to 20 per cent. in the more ordinary kinds. It varies also in each wine according to its age. The other constituents of wine are chiefly water, sugar, gum, extractive and colouring matters, gluten, sulphate of potassa, and chlorides of potassium and sodium. But the nutritive principles are extremely scanty.

In justification, we may say, of the position in which it is placed, as a dietetical fluid, Dr. Pereira states," wine, when used in moderate quantities, as to the extent of two or three glasses daily, proves a very grateful, and to those who have been accustomed to it, an almost indispensable stimulant." It quickens the action of the heart, diffuses warmth, augments muscular force, excites the mental powers, and banishes unpleasant thoughts;-is compatible with perfect health, and many who have thus employed it daily have attained a good old age: its regular use is better adapted for those who lead a life of labour and activity than for the indolent or sedentary. At the same time the twofold admission is made, that the most perfect health is compatible with total abstinence, and that its habitual employment is calculated to prove injurious. "To a person in perfect health, and who has been unaccustomed to it, no possible benefit can accrue from commencing its use." The preternatural excitement which it occasions is followed by a corresponding degree of depression, and the habit of using alcoholic stimulants creates a want for them. After giving Dr. Paris's testimony that "there exists no evidence to prove that a temperate use of good wine, when taken at seasonable hours, has ever proved injurious to healthy adults," Dr. Pereira concludes, "All I would assert is, that, for healthy individuals, wine is an unnecessary article of diet." (p. 426.) Wine differs somewhat in its action upon the system from ardent spirits. While those who drink the former are fat, lusty, and plethoric, spirit-drinkers are generally thin and emaciated. The disorders most likely to be induced by wine are those of the digestive organs, of the brain, gout, gravel, and dropsy; while spirits more frequently occasion diseased liver, and delirium tremens.

4. Condiments are of five kinds; saline, acidulous, oily, saccharine, and aromatic or pungent. Various organic principles of food escape entirely the action of the primary digestive processes, and are carried unaltered into the mass of the blood. Thus circulated throughout the tissues, they influence the functions of the organs, and probably in some instances, the processes of assimilation. Extractives, tannin, volatile oils, the acrid principles of cruciferous and alliaceous plants, thus escape the action of the digestive organs, retaining their sensible qualities in their progress through the economy: and the impressions they make on the different organs, as also their elimination, may frequently be observed. Thus, they produce effects independent of the nutritive powers of the aliments of which they form a part; these are for the most part stimulant, exciting the action of the heart and arteries, augmenting respiration and animal heat, or irritating special tissues.