Method we fhall obferve, will be to give the general Points, the chief Decifions and Results more at large; and for the Particulars on which thefe are founded, with the Details and Enumerations, content ourselves briefly to indicate them.

By Theory of Chemistry, it must be observed, p. 3. the Author, in a fenfe fomewhat different from what is ordinarily annexed to the Word, means, "a Syftem of general Truths, which the Che"mits have difcovered by comparing their par"ticular Experiments together; and forming "the refult thereof into general Laws to direct "their practice".

His Definition of Chemistry wherewith he fets p. 30.1 out, is, that it is" an Art teaching the perfor-Chemistry "mance of certain phyfical Operations; whereby what. "fenfible Bodies, or fuch as are capable of be

66

ing made fenfible, and contain❜d in Vessels,

are changed by means of proper Inftruments; "fo as to produce certain fingular Effects therein, whofe Caufe may alfo be perceived from the "Effects, for the use of various Arts."

The Object of Chemistry, he fhews, includes all Object of natural Bodies, which the Chemifts ufually divide Chemistry. into three Claffes, called Kingdoms, viz. Foffil, Vegetable, and Animal; each whereof he prosecutes in its order.

Fofils, vulgarly called Minerals, he defines to Foffils be" natural Bodies generated in the bofom of what. "the Earth, whofe Structure and Fabrick is fo

fimple, that no diverfity has ever been difcovered even by Microfcopes, between the "Veffels and the Juices contained therein."

Foffils are divided into Metals, Salts, Sul-Kinds of. phurs, Stones, Semi-Metals, and Earths-which

he proceeds to characterize in their order.

No. XVI. 1732.
VOL. III.

31.

Metals

what.

Metals, he defines," as the heaviest of Fof"fils, fufing by Fire, and coagulating again in "the cold, whereby they also become diften"dible, and ductile under the Hammer." How many. Of these there are ufually allowed fix, to which the Antients added a feventh, viz. Quickfilver, on Mercury,if account of its Refemblance in Weight, Simplia metal. city, &c. as alfo of the place where it is found; and its being fo eafily mifcible with Metals: which, however, the Author, after many of the Moderns, rejects out of the number, as wanting the neceffary Hardness, Ductility and Fixity: but he feems to allow it, with feveral of the Antients, for the Bafis or common Matter of all Metals.

The antient Perfians called the seven Metals Characters.by the Names of the feven Planets; and it is remarkable, that the Characters whereby Metals are to this day reprefented by the Chemists, are the fame with those used by Aftronomers to denote the Planets. Thefe Characters appear to be real, or philofophical; and bear a juft Analogy to the feveral Metals they reprefent. The Author proceeds to give an Explication of the reason, ftructure, and propriety of each.

He goes on to give fome detail of the feveral Metals, viz. Gold, Quickfilver, Lead, Silver, Copper, Iron, and Tin; of each whereof he gives the fpecific Characters, that diftinguish it from the other Metals, as well as from all other Bodies, viz. its degree of Weight, Simplicity, Fixity; Sound, Hardness, Fufibility, Elafticity, &c. together with the Forms, &c. wherein it is found, the manner of finding the Ore, of melting it down, and feparating the Metal from it; and lastly, preparing it for ufe.

To

To the History of the Metals, he fubjoins_41. fome Corollaries concerning their general Nature, Tranfmu and the Principles of Tranfmutation; which be-Metals. tation of ing curious, and containing the refult of the preceding Particulars, we shall here give the Reader more at large.

The lighteft Metal, then, he observes, is double the Weight of the heavieft non-metalline Body; whence appears the Folly of those who expect to make Metals by a change of other Bodies not metalline. Such Condenfation must be infinitely difficult in regard Weight, being the Index of corporeal Quantity, requires a kind of creative Power to give it.

The chief Indication of the intimate Affinity between the Matter of Metals, is their Refemlance in Weight.Hence none is fo like Gold as Quickfilver, if we confider the matter that is in each for as to their peculiar form, or that other principle which diftinguishes them, it is of further confideration. Gold then confifts of a Principles moft pure fimple Matter, very likeQuickfilver of Metals. connected by another pure, fimple, fubtil, fix'd Principle, diffus'd thro' the constituent Parts thereof, which binds them firmly both to one another, and to itfelf.This anfwers to Mer cury and Sulphur.

The other Metals confift of the fame ; but to gether with this have fome other lighter matter mixed with them, which is different in the different Metals, and is called Earth.-To which in fome Metals may be added a crude Sulphur.

Hence different Metals refolve into different Elements, both in refpect of their nature and number, which Refolution may be effected by Mercury, a refufcitating Salt, or Fire; in other Metals after other manners. Hence Metals are

A a 2

not

not so easily transmuted into each other as is commonly alledged, except in respect of their mercurial Parts, and by intirely deftroying their firft Form; confequently no more Gold can be procured from another Metal by Transmutation, than in proportion to the Quantity of Mercury contained in it.

Nor does it appear that any Metal, befides the fix above mentioned, can be produced by Art; tho' Helmont had the temerity to affert it of Mercury, fix'd by the Alkaheft.

Another Characteristic of the purer Metals is their Fixedness in the Fire, which no Impoftor can give to other matters, equal to what is found in Gold and Silver.- Add, that all their spurious Metals are defective in point of malleability.

The fix Metals when fused in clean Veffels appear all alike, and bear a perfect Refemblance to Mercury, both as to Figure, Colour, Solidity, the Sphericity of their Drops, the Attraction of their Parts, and their Manner of flowing and Mobility. Hence we may probably conclude that Mercury is a Metal, fufed by the eafieft Fire: Tin, a Metal flowing with a Degree of Heat fomething greater; and that if the Air were hot in the degree requifite for the Fufion. of Tin, it would be only a kind of Mercury emitting Fume and Froth: further, Lead would be Mercury in a degree of Heat fomething ftronger; but Mercury with these farther properties of foaming and pervading the Subftance of Veffels. Silver would be Mercury in a Fire much ftronger, and more powerful: Copper requires a ftill greater Heat to give it the Appearance of Mercury; and Iron the ftrongeft of all.

From

From Metals the Author proceeds to Salis, p. 43. which he defines to be foffil Bodies foluble Salts what.

both by Fire and Water, fo fimple, as that "each Particle retains the nature of the whole; and which excites a Senfe of Savour on the "Palate."

The Species of Salts are Sea Salt, Sal Gemma, Kinds. that procured from Salt-Springs, Salt-peter, Borax, Native Sal Ammoniac, Alumn, and the Vague univerfal Salt found in Mines.-Of each whereof the Author rehearses the specific Characters, Virtues, Origin, Formation, Place, &c.

46.

Sulphurs are defined, " foffil Bodies, which "in the Cold are hard, fo as to be reducible by Sulphurs what. grinding into a Flower, but foluble by a moderate Heat into the Form of melted Wax, capable of being all raifed, without Alteration, in a clofe Veffel, by force of Fire; "when fufed deflagrating intirely, and going off in a blue Flame and volatile Vapour, "mortal to Animals."

The Species of thefe are Sulphur vivum, the Kinds. common Shop Sulphur, Orpiment, Arfenic, both the White, Citrine and Red; Petroleum, Naphtha, Bitumens, Jews-Pitch Piffafphaltum, Jet, Pit-coal, Amber, and Oleum Terra: the particular Properties, Origin, &c. of each whereof he enumerates.

Stones are characterized as, "hard Foffils, not Stones " ductile but brittle, fixed in the Fire, and scarce what. "fufible by the greateft Heat; nor diffolvible? 5o. "in Water."

The Species belonging hereto are, 1o. Gems, Kinds. whofe Excellency and Value is founded on their great degree of Hardness, Solidity, Simplicity, and Luftre of Colour. 2°. Semitransparent Stones, as Agat, Aftroites, Armenian Stone, ToadStone, &c. 3°. Opake Stones, as the Ætites, AlaA a 3 bafter,