COMPOUND FOSSILS are all thofe Compound whofe Parts are diflimilar, or heterogeneous, or Fofils. may be divided into Parts of a different Nature; is Antimony may be refolv'd into Sulphur and a Metalline Part. The chief Species of compound Foffils are (1.) Hard Sulphurs, as Brimstone, Arfenic, Orpiment, Realgal, Bitumen, Afphaltum, &c. to which fome add Amber, Jet, and Ambergreafe. (2.) Liquid Sulphurs, as Pifafphaltum or Jew's Pitch, Naptha, Petroleum or Oil of Rock, &c. (3.) Semi-Metals, or kind of half Metals; as Antimony, Cinnabar, Marcafite, Bifmuth, Calamine, Cobalt, Pyrites, Vitriol, Magnet or LoadStone, with feveral other Mineral Stones and, Substances.

THE VEGETABLE KINGDOM fup- The Vegetable plies the Chemists with Bodies the moft fimple and Kingdom. refoluble of all others. The Nature and Texture of vegetable Subftances render them compleatly manageable by Chemical Operations; and therefore a good deal of this Part of Chemistry hath been introduced or practifed with the Galenical Pharmacy, as appears by what goes before. The Chemists refolve a Plant, or any vegetable Body, into the following Principles, viz. (1.) Water or Phlegm. (2.) A Spirit. (3.) Salt. (4.) An Oil, and (5.) An Earth, call'd Caput Mortuum. And each of these, more or lefs, from every Part, whether Root, Stem, Leaves, Flowers, Fruits, or Seeds of a Plant.

THE ANIMAL KINGDOM compre- The Animal hends all that Part of the Creation endued with Kingdom. fenfitive Life and fpontaneous Motion, that is, all Sorts of Animals. Every Part of an Animal alfo, whether Bone, Flefb, Hair, Horn, Shells, Humours, as Blood, Milk, Urine, &c. are fubject to the Chemical Analyfis. For the Chemists reduce any Animal Subftance into the following component

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Of Chemical
Operations.

Calcination.

component Principles, viz. (1.) A Spirit, being a fulphureous oily Matter, volatile, and mifcible with Water. (2.) Water, even from the driest Bone. (3.) A Salt, but neither Acid nor Alkaline, Fix'd or Volatile, but a compound Sort. (4.) Oil which is compounded of a Volatile Oil and Earth. (5.) Earth, a little more Volatile than that of Vegetables, and perfectly immutable.

HAVING taken a fhort View of the Materia Chemica, we now proceed to speak of the principal Operations of the Art: For though the Chemist pretends to no more than a Solution or Separation of the Parts of natural Bodies, or elfe an Union or Coagulation of them, yet divers Methods or different Operations are requifite to obtain either of thofe Ends; the chief whereof are the following, viz. (1.) Calcination. (2.) Filtration. (3.) Clarification. (4.) Diftillation. (5.) Diffolution. (6.) Fermentation. (6.) Fermentation. (7.) Digation. (8.) Extraction. (9.) Crystallization. (10.) Incorporation. (11.) Sublimation. (12.) Precipita tion. (13.) Cobobation. (14.) Amalgamation. Of which in Order.

CALCINATION is fuch a Management of Bodies by Fire, as brings them to a Calx, by forcing off all the Moisture, in which State they are eafily reducible to Powder, and is for that reafon term'd Chemical Pulverization. This Operation is feldom perform'd without Melting or Fufion, being chiefly employ'd about Metals and Salts: For after thofe hard Bodies are fufed or liquified for a long time, the fubtil Particles fly off, and the Fire is fo intimately mix'd and blended through all their Subftance, that the Fluidity can no longer fubfift, but there is produced a third fort of Body, very brittle and prous, and eafily reduced to Powder. To Calination belongs Vitrification, or turning Bodies,

as Flint, &c. into Glafs, or a Subftance pellucid and like thereto.

per

FILTRATION is a Method by which Filtration. Liquors are render'd fine and clear; and is form'd either by paffing the Liquor through a Paper, which by reafon of the Smallnefs of its Pores admits only the finer Parts through it; or elfe by laying a Cord or Piece of Cotton, &c. one Part in the Liquor, the other to hang over a Veffel placed below the faid Liquor; for through this it will afcend and drop over very fine, and clear from the foul and groffer Parts.

CLARIFICATION or DEPURA- Clarification. TION is another way of purifying and improving fome Medicines, as Decoctions, and other turbid Liquors, which is done by beating them up with the Whites of Eggs to a Froth, which upon boiling will entangle the groffer Parts, and carry them up to the Top in a tough Scum, which then is to be taken off with a Spoon, or feparated by the Hippocrates's Sleeve, which is a thick flannel Bag.

DISTILLATION is caufing by Fire an Distillation. Afcent or Elevation of the Particles of Bodies in Form of Vapour, which afterwards are condenfed and defcend in Form of Drops; and this is done by the Retort in a Sand Heat, by the Alembic, or by the Cold (or Common) Still: The Manner of which has been already hinted.

DISSOLUTION is the diffolving of the Dilution. natural Cohesion of the Particles of folid Bodies, by which Means they are fet in Motion, and the Bodies are brought into a State of Fluidity. Thus Salts are diffolv'd by various Menftruums, as Air, Water, &c. Thus alfo Gold diffolves in Aqua Regia, and Silver in Aqua Fortis. Lastly, Metals will diffolve in a Saline Menftruum, and Refins in a Sulphureous one. FERMEN

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Fermentation.

Digeftion.

ExtraЯion.

FERMENTATION is a Term of a very lax and vague Idea, though in general nothing more than an inteftine Motion caufed in the Particles of Bodies by the Admixture of fuch Matter as contains fubtil fpirituous Particles wrapped up in vifcid ones, is understood thereby. For the fpirituous Particles being always upon an Endeavour to release and extricate themfelves from the vifcid ones, will, till they obtain their Liberty, produce a Commotion in the Medium wherein it happens. Of Fermentation there are various Species, which are of different Ufes in the Chemical Pharmacy, and efpecially the Fermentation of Vegetables and their Juices, whereby their Medicinal Efficacies are exalted by difengaging and feparating the finest and most spirituous Parts thereof.

DIGESTION is that Solution of Bodies as is made by Menftruums by the Affistance of Fire, and differs in little elfe than the Fire from the common Diffolution of Bodies before defcribed. And indeed all kinds of Solution depend upon this general Principle, viz. That the Particles of the Body to be diffolved be by Fire, or otherwife, fo far attenuated that their Specific Gravi ties become less than that of the Menstruum, or Tenacity and Refiftance thereof; for otherwife they could not be sustain❜d or fufpended therein, and mix'd therewith; but would fink directly to the Bottom, and there confolidate again.

EXTRACTION, taken in its largest Senfe, fignifies any Solution of Bodies made by Menftruums, wherein not the whole Subftances, but only certain Particles are carried off, or absorb'd thereby. But what is properly call'd Extraflion, and is here intended, is fuch an Infrillation, or thickening of a Solution, as when a certain Quartity of the Menftruum is drawn off, the remains

ing Mixture is reduced to the Confiftence of Honey. But of this I have already spoken under the Galenical Pharmacy.

CRYSTALLIZATION is the bringing Crystalliza

of the Particles of Saline Subftances into fuch a State or Confiftence as to refemble the Form of Crystal, but variously modified according to the Nature and Texture of the Salts. The Method is this; the Saline Body is diffolv'd in Water, afterwards the Solution is filter'd, which being evaporated till a thin Film appear on the Surface, it fpontaneously runs into Crystal. .

tion.

INCORPORATION is a Procefs which Incorporation. brings and joins together, by the Interpofition of a particular Body, fuch others, as in themselves are incapable, or very difficult to be mix'd or incorporated together. Thus Oils and Syrups are incorporated in Eclegma's and Linctus's, by means of Sugar, Salt, or fuch like Subftances; thus a Mixture of Turpentines, Balfams, &c. with aqueous Liquors is effected by the Interpofition of the Yolk of an Egg; and thus a Mixture of Metals is likewife produced by Amalgamation.

SUBLIMATION is the raifing and ele- Sublimation. vating the folid and dry Parts of Bodies by means of Fire, in like manner as the fluid Parts are rais'd by Distillation. The Subjects of this Procefs are all volatile Bodies, or fuch which contain volatile Parts, as Salts of Animal Substances; thus the Salts of Minerals are fublimed, and the Salts of Vegetables, as Salt of Tartar, &c. By this Method are obtain'd thofe fine foft Subftances call'd Flowers, as Flowers of Sulphur, Antimony, Bismuth, &c.

PRECIPITATION is that Process by Precipitation. which Particles of Bodies diffolved and fufpended in a Menftruum are made to fink or fall to the Bottom thereof. The Particles fometimes precipitate

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