Графични страници
PDF файл
ePub

COMPOUND FOSSILS are all those Compound whose Parts are didimilar, or heterogeneous, or Fossils. may be divided into Parts of a different Nature ; as Antimony may be resolv'd into Sulphur and a Metalline Part.' The chief Species of compound Fossils are (1.) Hard Sulphurs, as Brimstone, Arsenic, Orpiment, Realgal, Bitumen, Asphaltum, &c. to which some add Amber, Jet, and Ambergrease. (2.) Liquid Sulphurs, as Pilasphaltum or Jew's Pitch, Naptha, Petroleum or Oil of Rock, &c. (3.) Semi-Metals, or kind of balf Metals; as Antimony, Cinnabar, Marcasite, Bismuth, Cala: mine, Cobalt, Pyrites, Vitriol, Magnet or LoadStone, with several other Mineral Stones and Subiances.

THE VEGETABLE KINGDOM sup- The Vegetable plies the Chemists with Bodies the most simple and Kingdom. resoluble of all others. The Nature and Texture of vegetable Substances render them compleatly manageable by Chemical Operations ; and therefore a good deal of this part of Chemistry hath been introduced or practised with the Galenical Pharmacy, as appears by what goes before. The Chemists resolve 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, callid Caput Mortuum. And each of these, more or less, 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. sensitive Life and spontaneous Motion, that is, all Sorts of Animals. Every Part of an Animal also, whether Bone, Flejh, Hair, Horn, Sbells, Humours, as Blood, Milk, Urine, &c. are subject to the Chemical Analysis. For the Chemists reduce any Animal Substance into the following L 1 2

component

component Principles, viz. (1.) A Spirit, being a fulphureous oily Matter, volatile, and mifcicle 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. 14. ! Oil which is compounded of a Volatile Oil and Earth. (5.) Earth, a little more Volatile than

that of Vegetables, and perfectly immutable. Of Chemical HAVING taken a short View of the Maters Operations. Chemica, we now proceed to speak of the prin

cipal Operations of the Art: For though the
Chemist pretends to no more than a Solution or 5-
paration of the Parts of natural Bodies, or elie
an Union or Coagulation of them, yet divers Me-
thods or different Operations are requisite to ob-
tain either of those Ends; the chief whereof are
the following, viz. (1.) Calcination. (2.) E.
tration. (3.) Clarification. (4.) Distillation. (5.)
Disolution. (6.) Fermentation. (7.) Digelse.
(8.) Extraction. (9.) Crystallization. (10.) Ix-
corporation. (11.) Sublimation. (12.) Precizitz-
tion. (13.) Cobobation. (14.) Amalgamation. Of

which in Order. Calcination. CALCINATIO N is such a Management of

Bodies by Fire, as brings them to a Ca’x, by forcing off all the Moisture, in which State they are easily reducible to Powder, and is for that reason term’d Chemical Pulverization. This Operation is feldom perform’d without Meltirg or Fusion, being chiefy employ'd about Metis and Salts : For after those hard Bodies are fujou or liquified for a long time, the subtil Particles Ay off, and the Fire is so intimately mix'd and blended through all their Substance, that the Fluidity can no longer subsist, but there is produced a third sort of Body, very brittle and parous, and easily reduced to Powder. To Calcination belongs Vitrification, or turning Bodies,

[ocr errors][merged small][ocr errors]

as

as Flint, &c. into Glass, or a Substance pellucid and like thereto.

FILTRATION is a Method by which Filtration. Liquors are render'd fine and clear; and is

perform'd either by passing the Liquor through a Paper, which by reason of the Smallness of its Pores admits only the finer Parts through it; or else by laying a Cord or Piece of Cotton, &c. one Part in the Liquor, the other to hang over a Veffel placed below the said Liquor ; for through this it will ascend 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 grosser Parts, and carry them up to the Top in a tough Scum, which then is to be taken off with a Spoon, or separated by the Hippocrates's Sleeve, which is a thick Aarrnel Bag.

DISTILLATION is causing by Fire an Disillation. Ascent or Elevation of the Particles of Bodies in Form of Vapour, which afterwards are condensed and descend 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 Disolution, natural Cohesion of the Particles of folid Bodies, by which Means they are set 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 also Gold diffolves in Aqua Regia, and Silver in Aqua Fortis. Lastly, Metals will dissolve in a Saline Menftruum, and Refins in a Sulphureous one.

FERMEN

L13

Fermentation. FERMENTATIO N is a Term of a very

lax and vague Idea, though in general nothing more than an intestine Motion caused in the Particles of Bodies by the Admixture of such Matter as contains subtil spirituous Particles wrapped up in viscid ones, is understood thereby. For the spirituous Particles being always upon an Endeavour to release and extricate themselves from the viscid 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 Uses in the Chemi:a! Pharmacy, and especially the Fermentation of Vegetables and their Juices, whereby their Medicinal Efficacies are exalted by disengaging and separating the finest and most spirituous Parts

thereof. Digeftion.

DIGESTION is that Solution of Bodies as is made by Menstruums by the Alistance of Fire, and differs in little else 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, so far attenuated that their specific Grai. ties become less than that of the Merjiruum, or Tenacity and Resistance thereof; for otherwile they could not be sustain'd or suspended therein, and mix'd therewith ; but would sink directly

to the Bottom, and there consolidate again. Extraflion. EXTRACTION, taken in its largest Serife,

signifies any Solution of Bodies made by Minstruums, wherein not the whole Substances, but only certain Particles are carried off, or abforb'i thereby. But what is properly callid Extralia, and is here intended, is such an Infrillation, or thickening of a Solution, as when a certain Quirtity of the Menstruum is drawn off, the remain

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

CRYSTALLIZATION is the bringing Crystallizaof the Particles of Saline Substances into fuch a tion. State or Consistence as to resemble the Form of Crystal, but variously modified according to the Nature and Texture of the Salts. The Method is this ; the Saline Body is diffolvid in Water, afterwards the Solution is filter'd, which being evaporated till a thin Film appear on the Surface, it spontaneously runs into Crystal. .

INCORPORATION is a Process which Incorporation. brings and joins together, by the Interposition of a particular Body, such 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 LinEtus's, by means of Sugar, Salt, or such like Substances ; thus a Mixture of Turpentines, Balsams, &c. with aqueous Liquors is effected by the Interposition of the Yolk of an Egg ; and thus a Mixture of Metals is likewise produced by Amalgamation.

SUBLIMATION is the raising and ele. Sublimation, vating the solid 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 Process are all volatile Bodies, or such which contain volatile Parts, as Salts of Animal Substances ; thus the Salts of Minerals are sublimed, and the Salts of Vegetables, as Salt of Tartar, &c. By this Method are obtain'd those fine soft Substances call’d Flowers, as Flowers of Sulphur, Antimony, Bismuth, &c.

PRÉCIPITATION is that Process by Precipitation. which Particles of Bodies dissolved and suspended in a Menstruum are made to sink or fall the Bottom thereof. The Particles sometimes pre

cipitate

LI4

« ПредишнаНапред »