DIVISION of INORGANIC INANIMATE

BODIES.

Norganic Inanimate Bodies may be divided into Salts, Earths, Inflammable Subftances, and Metals.

I. SALT S.

SALTS are bodies foluble in less than 200 times their weight of water, affect the tongue with a fingular tafte; and, when the water in which they are diffolved is evaporated, form themfelves into regular angular figures, called crystals. These cryitals are of different figures in different falts, each falt forming crystals of a figure peculiar to itself. Thus the crystals of common falts are cubes; thofe of faltpetre, hexagonal prisms, or fix-fided columns; those of other falts of different figures. Some natural historians have claffed falts according to the figure of their cryftals; but chemifts divide falts into fimple and compound.

Simple falts are of two kinds, alkalis and acids.

There are three alkalis, the foffil, vegetable, and animal. The ancients produced one of thefe from the afhes of the herb kali or glafswort; hence the general name al kali, the (falt produced from) kali; and because this falt was used in making glass, the herb is called glasswort.

The ALKALIS are divided into volatile, which fly off in the open air, as the animal alkali; and into fuch as are fixed and which do not evaporate, as the foil and vegetable alkali.

The diftinguishing qualities of alkalis are, that they change the blue colour of vegetables into green, unite with oil to form foap, and with fand to form glafs.

The acids are alfo divided into fofil, vegetable, and animal. The FOSSIL ACIDS are, the vitriolic acid, the nitrous acid, the muriatic or marine acid, and the boracic acid.

The VITRIOLIC acid is fo called, because it was first produced from the compound falt called vitriol; but the vitriolic acid now used is produced from fulphur, and hence the modern French chemists call it fulphuric acid.

The

The NITROUS acid is fo called, because it was obtained from mitre or faltpetre; the MURIATIC or marine acid, because it was obtained from muria or fea-falt; and this acid is fometimes called fpirit of falt; the BORACIC acid, because it was obtained from borax, a falt which comes from the Eaft Indies, and is dug up in a cryftalifed state from certain falt lakes in the king

dom of Thibet.

Befides thefe foffil acids there are feveral others which modern chemists have discovered; as arfenic acid, from arfenic; the fluoric acid, from fluor or spar, &c.

VEGETABLE acids are either native or fictitious. The native are obtained from the juices of certain fruits and plants, as from lemons, currants, and other four fruits; or from the leaves of ferrel, and other acid plants. The fictitious are, VINEGAR, which is produced either from the fermentation of fweet fruits or grain; and TARTAR, which is found adhering to the bottom and fides of veffels in which wine has been kept.

The ANIMAL acids are, the phofphoric acid, obtained from moft animals; the formic acid, produced from ants; and feveral other acids produced from infects, as, the bombye from filkworms; apic, from becs, &c.

The diftinguishing properties of acids are, that they change the blue colours of vegetables into red, they effervefce with alkalis, metals, and fome earths, which, poffeffing this property in common with alkalis, are called alkaline earths; as, chalk, lime, magnefia, &c.

The COMPOUND SALTS are thofe which are formed from the union of any acid, either with an alkali, an earth, or a metal. Thus, if the nitrous acid be united with the vegeta, ble alkali, there refults a compound falt called nitre or faltpetre,

From confidering the nature and quality of this falt, it ap pears very different from the nitre of the ancients, Plin. xxxi. 10. 46. The modern nitre does not effervefce with acids, which the nitre of the ancients did, thus, As vinegar upon nitre, &c. Prov. xxv. 20. Nor does our nitre anfwer the purpose of soap, as that of the ancients, Though thou wash thee with nitre and foaf, Jerem. ii. 22. But both thefe qualities are found in the foffil alkali; and hence modern chemifts conclude the nitre of the ancients to have been the foffil alkali, which abounds in many parts of the eaft, where it is called natron, and in fomẹ places trona; both of which words have a great resemblance to nitrum or nitron.

To enumerate all the compound falts would be needlefs in #his place,

Thofe

Thofe compound falts which confift of acids and alkalis are called NEUTRAL SALTS, from the fuppofition that they are neither alkali nor acid.

NEUTRAL SALTS are formed by acids and alkalis; and when the acid is firft added to the alkali, an effervefcence enfues, which decreases in proportion as more acid is added, till at length the addition of the acid no longer caufes an effervefcence. The alkali is then faid to be faturated with the acid, or the alkali and acid are faid to be mutually faturated with each other. Thus the acids may be faturated with metals and absorbent earths, to form compound falts with thefe fubftances; and the falts thus formed are called metallic or earthy falts, or fometimes falts with metallic or earthy bafes. In a similar manner, as the acids may be faturated with alkalis, metals, or earths; fo falts of all kinds may faturate water; for a certain quantity of water will only diffolve a certain quantity of any falt; and when the solution is fo made it is faid to be a fatus rated folution:

ii. EARTH S

EARTHS, or earthy bodies, are diftinguifhed from falts by their not being foluble in water; from inflammable bodies, by not being inflammable; and from metals, from their inferior weight.

All earthy bodies may be reduced to the following claffes; Abforbent earths, Plaftic earths or clay, Vitrifiable earths, or fuch as melt into glafs, and Apyraceous earths, which remain unaltered by fire.

ABSORBENT EARTHS are diftinguished from other earths by their effervefcing with acids, as, calcareous earths, chalk, lime flone, marbles, fpars of different kinds, one of which, found in Iceland, is remarkable for the property of doubling all objects viewed through it; Barytes, or heavy earth, forming the heaviest of all ftones, which are about four times and a half their weight of water; the Bolognian ftone, firft found near Bologna, in Italy by a fhoemaker, who applied himself to alchemy, which after being expofed to the light, has the power of retaining it for fome time, and of fhining in the dark. Magnefia, which is feldon found in a pure ftate, but generally combined with other fubftances, as with the vitriolic acid in certain mineral fprings, efpecially

at Epfom in Surrey; or with the muriatic acid in fea-water; ot with different earths, as in various ftones, especially in the Lapis Serpentinus, or Ollaris. This is a stone so soft that it may be turned in a turner's lathe, and pots (olle) and pans made of it, which are remarkably clean, and refift the action of fire.

2. Plaftic or Argillaceous earths, are fuch as are friable or pul verifable when dry, but form a tough ductile paste with water, and when burnt become extremely hard, as clays, of which there are various kinds. Clays, when baked, conftitute all the varieties of bricks, pottery, and porcelain.

3. Vitrifiable earths are fuch as differ from the two former by wanting the properties above mentioned. They melt in a due degree of heat, but they generally require fome other fubftance to be mixed with them to promote their fufion, and are so hard that they strike fire with flint, and a file makes no impression on them. They are commonly found, not in an earthy ftate, but in the form of ftanes, flints, agates, quartz (a whitish semitransparent ftone, which has the property of emitting flashes of light, when two of them are rubbed one against the other in the dark, accompanied with a strong fulphureous phosphoric fmell), granites, fand-ftone, fand, gravel, &c. The pure filicious earth, as it is called, has been found in the bottom of fome lakes in the Highlands of Scotland. To this clafs belong most of the gems, jafper, calcedony, carnelian, so called from its flesh colour, onyx, fardonyx, opal, tourmaline, garnat, amethyst, topaz, fapphire, emerald; as alfo bava, bafaltes, pumice, and other volcanic matter; fchoerl, a fubftance of a cryftalline appearance and of different colours, and many fpecies of whin-flone.

4. Apyraceous earths differ from the reft in having a peculiar plated or fibrous texture, and wanting the properties of the other earths, as, Talk, confifting of thin fcales or plates, fo large and tranfparent that they are ufed for windows in Ruffia; Afbestus, confifting of fibres, which are fometimes fo fine as to be capable of being wrought into cloth; and, from its power of withftanding the fire (as the name denotes), it was used by the aneients as a covering for the body when burnt, to preferve the hes; Mountain leather and cork, which are ftones perfectly pliable like thefe fubftances.

III. IN

III. INFLAMMABLE SUBSTANCES.

INFLAMMABLE fubftances are fuch as poffefs the property of being confumable by fire, and are diftinguished by emitting heat and light.

Moft bodies which belong to this clafs are mixed with certain impurities, chiefly of an earthy nature, which prevents their being entirely confumed, and therefore leave a refiduum called afbes.

All inflammable fubftances are violently acted upon by the Vitriolic and nitrous acids, except camphor and naptha, or liquid bitumen, Plin. ii. 105. f. 109.

The mineral inflammable substances are amber, in which are found fishes, infects, and vegetables, which fhews that it has once been liquid; ambergrife, rock oil (petroleum), both folid and liquid; bitumen, Plin. 35. 15. 51.; fulphur or brimstone, either pure or mixed with other fubftances, Plin. Xxxv. 15./.50.; afphaltus, v. -um, a bituminous fubftance found on the furface of the Dead Sea in Palestine, jet, peat, turf, &c.

Of inflammable fubftances, one of the moft remarkable is coal.

The use of coal for burning was unknown to the Romans. It was first discovered by the Britons, as it is thought, near Manchester, fome time before the invasion of Julius Cæfar. But for ages after the discovery wood continued to be generally used for firing as long as the forests abounded.

The first public notice of coal is in the reign of Henry III. who, in 1272, granted a charter to the town of Newcastle, allowing the inhabitants to dig for coals. They were not, however, brought into common ufe till the reign of Charles I. and were then fold at 17 s. a chalder or chaldron.

Some years after the Restoration, about 200,000 chaldrons were burnt in London, at the Revolution above 300,000, and at present 600,000. In Ireland, although they have coal, yet they take annually a confiderable quantity both from England and Scotland.

There are several other countries in Europe which have coalmines, as, France, Liege, Germany, and Sweden; and in America, Newfoundland, Cape-Breton, Canada, and fome of the New England provinces. But in all these the coal is of a qua