Sulphurous acid is found in some mineral waters; alkali, or soda, in others; and salts, as sulphats, nitrats, muriats, and carbonats of soda, or lime; and in chalybeate waters, the carbonat of iron.

Obs.-The test of the presence of carbonic acid in any mineral water is an infusion of litmus, which will he turned red by water containing it; and this neid also gives the briskness of champaign into whatever it enters, and an acidulated flavour to water. Any acid contained in any water, may be detected by its turning the infusion of violets, red. Alkalies in water may, in like manner, be detected, by turning the infusion of violets, green. The infusion of dry violets, or paper stained with them, answers best. The infusion of turmeric, or paper stained with turmeric, is rendered brown by alkalies; or reddish brown, if the quantity is minute. When the change is temporary, it is volatile alkali. Sulphur and bitumen may be detected, by the smell and taste. Iron, in mineral water, may be detected by Prussiat of potass, which will precipitate it, and tinge it blue. The solu tion of galls also is an exquisite test of the presence of iron. When there is copper in water, it will shew itself on the surface of any piece of bright iron put into it. If arsenic, the residuum will tinge copper, white.

531. The vegetable kingdom affords manifold beautiful instances of the chemistry of nature. Water may be esteemed the chief pabulum of vegetables, which reducing it to its first principles, appropriate its hydrogen and oxygen in the formation of their respective constituent parts.

Air, light, and heat, aid the several processes, whilst the application of manure not only adds' to the quantity of nutriment, but at the same time stimulates the vegetating principle to increased action. (See No. 443 to 448.)

532. Vegetable substances, subjected to

U

FERMENTATION, produce, under different cir ́cumstances, either WINE, from which AtcoŊÖL may be obtained, or the ACETIC ACID, termed vinegar. Besides which, the following acid. may be obtained from vegetables: benzoic, citric, gullie, malic, oxalic, phosphoric, prussic, tartaric, &c.

533. BITUMENS are certain bodies, which have considerable resemblance to resins and oils, and are found in subterraneous situųtions.

Obs-Naphtha is a yellow and transparent fluid, voJatile, strongly smelling, and very light; and Petroleum resembles naphtha.

Jet is also a bituminous substance, holding much car boo, Canal coat is of the same class, but contains more earth. Common coal has its bituminous constituent intersected by plates of carbonate of lime and sulpburet of iron.

633. Animal substances, although contain ing some of the same principles found in the vegetable kingdom, still manifest considerable differences in their respective analyses.

Ostatine or jetty, employed in the arts, as glue, is abundantly obtained from the skin of animals.

Albumen, is that substance which forms what is termed the white of eggs.

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 mitrate 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 washy ing of clotted blood.

Urea is a yellow.crystalline substance, of a peculiar smell and taste, obtained from urine,

A4 Saccharine.Matter is formed in animal progeyedi ei nel

Bones are formed of cartilage, gelatine, and fat, deriving their bardness from the earthly 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 ani mal matter disposed in Jamelia. In bones, the phosphate of lime is most abundant; but in shells, the carbonate of lime prevails,

The Muscles, or flesh of animals, contain albumen, gelatine, and extractive matter, but are chiefly composed of fibrin,

The Skin, is divisible into the cuticle, epidermis or scarfskin, 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.

--Spermaceti is found in the head of the spermaceti whale; whilst from its blubber is obtained truin oil, The fat of some animals, as of the ox and sheep, becomes a hard substance, whilst that of hogs is much softer.

"Marrow, which is contained in the long bones of unimals, is an animal fixed oil, of peculiar properties, somewhat resembling butter.

Hair, exists in the different forms of down, wool, and bristles.

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 coagulùm, and the serum or fluid part. The cruor contains "fibring 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 is of an animal nature. The serum is a fluid of a greenish yellow, which coagulates at 156o, and is divisible into albumen and serosity. The blood contains water, fibrin, albumen, benzoic acid, hydrosulphuret of ammonia, suda, subphosphate of iron, muriate of soda, phosphate of soda and of lime.

Bile, secreted by the liver of animals into the gallbladder, is of a dark yellowish green colour, of an une tnous feel, a peculiar smell, and a bitter taste. It con

tains a resin, and a substance peculiar to bile, pa placumel, a whitish solid substance formed into globa with water and salts, chiefy phosphate of lime, muriate sulphate, and phosphate of soda,

Definition 1.--When me chemical substance de pases anather, it is called a chemical test.

2.- If salt be mixed in water, it is said to be in rolle tion, and the water is called the menstruum,

3.-If no more salt will dissolve, the water is st. a be saturated,

4.-If we would extract the salt, we must evapealset the water by heat, with a still, or retort, or alembic; afhol if the papour from either of these pass through aspiml tube or warm, to the receiver, we shall have distilkin water; and the residuum of salt will remain in the still

5.-Solid substances are reduced into powders by fa turation, pulverization, and levigation; brittle subali y are pulverized by means of hammers, pestles and a tars, stones and mullers,

6.-The separation of the finer parts of bodies from the coarser is performed by means of sifting or wash

1.- Filtration is a finer species of sifting, perfomed through the pores of paper, Åannel, fine linen, sand, Ác, It is used only for separating fluids from solids,

8.- Fusion, or the melting of a solid body, by the action of heat, requires, according to their several natures, erish cibles of different kinds strong enough to resist the firgi made of earthenware, porcelain, or a mixture of clay and powder of black-lead, or of black-lead altogether

9,-Sometimes crucibles have covers made of earthenware, but in other cases the fused metal must be exposed to a current of air; for this purpose the crucibles are broad and shallow, and are called cupets,

10,- Blou-pipes are used for directing the flame of any Candle or lamp against any piece of ore or other substance required to be examined; and when the inflam-high gipes are used instead of common air, the heat is mole,” powerful,

11. The various degrees of heat which are required for the performance of chemical operation», tender it res Crary that the chemist should also be possessed of a farmace, Bee Grammar of Philosophy.