eggs. It is coagulated by heat, by acids, and, though in a less degree, by alcohol. Dr. Bostock, who has made some most important experiments on the more simple animal substances, observes, that one part of dried albumen dissolved in nine parts of water, forms a solution which becomes perfectly solid when exposed to heat equal to its coagulation; and that one drop of a saturated solution of oxymuriate of mercury dropt into water holds yo part of its weight of albumen, produces milkiness, and a subsequent precipitate. MUCUS has been determined by the same chemist to be instanced in the thickening substance contained in saliva, and yields a precipitate on the addition of nitrate of silver, and more fully by acetate of lead. FIBRIN, or the fibrous part of the blood, is obtained from the muscles of animals, or by agitation and washing of clotted blood; thus is yielded a white fibrous substance, without taste or smell. UREA is a yellow crystalline substance, of a peculiar smell and taste, obtained from urine. SACCHARINE matter, not, perhaps, exactly agreeing with the sugar of vegetables, is formed in animal processes. Honey may be, perhaps, justly asserted to be of vegetable formation, and to have undergone but little change by the bee; but milk may be made to yield a syrup, from which sugar-like crystals may be obtained, and which have been named sugar of milk. substance approaching still nearer to vegetable sugar is found in large quantities in the urine of

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patients afflicted with diabetes. Substances also are formed in animals approaching so nearly to resins, as to merit the name of ANIMAL RESINS. Under this head may be placed the resin of bile, castor, and ambergris. BONES are formed of cartilage, gelatine, and fat, deriving their hardness from the earthy salts which exist in them abundantly. These are phosphate and carbonate of lime, and perhaps a small proportion of magnesia. SHELLS are formed of the salts of lime, deposited on animal matter disposed in lamellæ. In bones, the phosphate of lime is most abundant; but in shells, the carbonate of lime prevails. CRUSTS of lobsters, crabs, &c. which are termed crustaceous animals, are also formed of animal matter, blended with calcareous salts. But in the crusts of animals the proportions of the calcareous salts differ from those of bones and of shells, being, as it were, intermediate; the quantity of the phosphate of lime being large, and of the carbonate less than in shells; and the carbonate being in larger, and the phosphate in less proportion, than in bones. HORNS contain a very small portion of earthy matter; the albumen and gelatine, which enter into their composition, are therefore very abundant. Hence, by the well managed employment of heat and moisture, they may be rendered so soft and flexible as to be bent into different shapes, and even impressed by moulds for various useful and ornamental purposes. The NAILS, CLAWS, and Hoofs of different animals being composed of the same con

stituents as horns, differ in very few respects from them. The MUSCLES, or the flesh of animals, contain albumen, gelatine, and extractive matter, but are chiefly composed of fibrin. The SKIN is divisible into the cuticle, epidermis or scarf-skin, and the cutis or true skin. The former appears to consist chiefly of coagulated albumen, and the latter of gelatine: hence, it may be observed, that it is this part from which the jelly is obtained. The MEMBRANES appear to possess most of the chemical properties of the cutis. The TENDONS, those substances in which the muscles terminate, are also resolvable by boiling into jelly; showing that it is gelatine which chiefly enters into their composition. The nature of the substance of the BRAIN and NERVES has not yet been satisfactorily ascertained.—OILS: the oily substances of animals is found under various modifications in different animals and in different parts of the same animal: thus spermaceti is found in the head of the physeter macrocephalus, or spermaceti whale; whilst from its blubber is obtained train oil. The fat of some animals, as of the ox and sheep, becomes a hard substance, whilst that of hogs is much softer, and is therefore called hog's-lard. MARROw, which is contained in the long bones of animals, is an animal fixed oil, of peculiar properties, somewhat resembling butter. HAIR, which exists in the different forms of down, wool, and iristles, varies in appearance in animals, though, perhaps, but little in its composition. The notice of this analysis will

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serve to show how impossible it would have been to compress the analysis of the different substances mentioned in this Compendium. The component parts of black hair are, 1. A peculiar animal matter, constituting the greatest part.-2. White solid oil, in small quantity.-3. Greyish green oil, in larger quantity.-4. Iron.-5. Oxide of manganese.-6. Phosphate of lime.-7. Carbonate of lime.-8. Silica.-9. Sulphur. FEATHERS appear much to resemble hair in their component parts. The quill, Mr. Hatchett has shown, is chiefly formed of hardened albumen. BLOOD separates, on standing, into cruor or coagulum, and the serum or fluid part. The CRUOR contains fibrin, which is manifested in a white, solid, and elastic form, by washing the clot: and the colouring matter of the blood, which was long supposed to be iron, but which Mr. Brande has shown to be of an animal nature. The SERUM is a fluid of a greenish yellow, which coagulates at 156°, and is divisible into albumen and serosity. The blood contains water, fibrin, albumen, benzoic acid, hydrosulphuret of ammonia, soda, subphosphate of iron, muriate of soda, phosphate of soda and of lime. Dried blood, calcined with potash, dissolved and added to solution of sulphate of potash, deposits a green precipitate, which, being digested in muriatic acid, becomes that beautiful pigment Prussian blue, and which, by proper chemical treatment, yields an acid, the Prussic acid, possessing peculiar properties.

Milk is secreted in the mamma of females of the class of mammalia, and differs in some respects in

different animals, but agrees in its general properties; so that the properties of cows' milk may be assumed as illustrative of those of milk in general. On the surface of milk at rest, a thick unctuous yellow substance collects, named cream. This being removed, and rennett, yielded by the inner membrane of the calf's stomach, being added to the remaining milk, it soon separates into curd and whey. CREAM being agitated by churning, separates into a milky fluid, called butter-milk, and the oil of the milk, as butter. The CURD, separated by coagulation, and subjected to pressure, forms cheese. BILE, secreted by the liver of animals into the gall-bladder, is of a dark yellowish green colour, of an unctuous feel, a peculiar smell, and a bitter taste. It contains a resin, and a substance peculiar to bile, named picromel, a whitish solid substance formed into globules, with water and salts, chiefly phosphate of lime, muriate, sulphate, and phosphate of soda. CERUMEN, or wax of the ear, is supposed to resemble the resin of bile. SALIVA contains, with some of the salts just mentioned, mucilage and albumen; the latter being only in a state of diffusion. URINE, as it cools, yields a peculiar urinous smell, and deposits a sediment varying under different circumstances. The characterising substance of urine is termed urea, which yields the uric acid; and which, combined with soda, forms the general saline deposit of urine. During fevers and diseases of the liver, a rose-coloured sediment is deposited, found to contain an acid named rosacic. Besides albumen and resin, urine also contains va