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Fomethir Bodies. Earthso

third, the Rigidity of the Particles of the Men. struun. The fourth is Fire, which agitates and inforces the Action of the Particles of the Menstruum. But the insufficiency of mechanical Power for producing the Effects of many Menftruums, the Author Thews by a Rationale ; adding a rehearsal of those Menftruums wherein something more is necessary: such are Water and aqueous Bodies, Salts, and faline Bodies, as Sapo's, &c. also Earths, and terrestrial Bodies : Sulphurs, and Resins.

For Oils, and oily Menftruums, he shews that Oily Men: the Action of Fire, Water, Acids, Alkalies, and fruums. the Spiritus reétor, have a great share in the Effects thereof. For spirituous ones, as Alcohol, the an- Spirituous, , tient Chemists make a great Secret of it, infomuch that Weidenfeld is of opinion this is the only thing they conceal. .

Those popularly called spirituous Menftruums are different from Alcohol, and are confidered by the Author under the two Heads of alcaline and acid Spirits. The alcaline subdi. Alcaline. vide into those which are simple, as Spirit of Sal Armoniac ; and compound. For the acid kind, tho' usually by Chemists considered as Spirits, the Author shews from several Reasons, that they belong rather to the Class of Salts, and therefore refers their Considerations to that head..

Salts make a capital Article in the Business saline. of chemical Menstruums. When pure, they : consist of Elements too minute to be perceivable even by a Microscope ; so that no Light can be had thence with regard to their Figures : Theusual Manner of considering them, is as associated with other Bodies, particularly Water and Earch ; in which State it is, that they chiefly , make the Object of chemical Operations.--

Salts then may be divided into such as either differ in their Principles, or in the Body or Basis combined with them, or in boch: with regard to the former, Salts and consequently săline

Menftruums are subivided into, Fixed Al- ,1. Fixed Alcali; the Character

1. Fixed Alcali ; the Characters whereof are, cali. that it " is of a vegetable Origin, procured

o from Plants by burning them to ashes ; re-
66 mains long fixed in the Fire ; diffolves in a
“ moist Air, and will not keep long dry in the
o closest Vessel ; affords a hot pungent Savour,
“ accompanied with a Sense of Acrimony, and
66.even something of an urinous Taste (whence
6 the Salts of this Class are frequently, tho'with-
" out much Propriety, called urinous Salts;) that
“ when burnt, it yields no Smell, on account of
« its fixity ; when mixed with Acids, makes
“ an Ebullition, and grows hot ; mixed with
" the Juices of Tournfol, Roses, or Violets, turns
" them from a green Colour to blue: when ap.
66 plied to the warm Body, raises an Inflamma-
" tion, and Eschar. And lastly, that it has a
" Faculty of deterging and cleansing Bodies."

The Salts of this Class are procurable in greater or less quantity from all Plants; moft plentifully from that called Kali, and least from thofe which yield a pungent Smell, as Leeks, and the like. Add, that not being native, but the mere Creatures of the Fire, they are liable to be destroyed again. ..

Fixed Alcalies are various, according to the Degrees of Purity wherein they are procured ; the most ordinary is procured from Pot-Ashes, by diffolving them in hot Water, and skimming off the Salt that swims a-top. Another is that procured from Wine-Lees, by burning them; another from Tartar by Distillation ;

others

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others from Salt-petre; others from Tartar and Salt-petre ; others from Nitre and Antimony. Alcalies are also of different Degrees of Purity, according as more or less of the acid Salt, Oil, and Earth of the Vegetables, is left adhering to them; as also according to the different Bodies added to them.co.

Some other Properties of fixed Alcali, are, Powder's its Power of attracting Water, and retaining it when attracted ; a Power of repelling Air, or perhaps attracting it ; of mixing greedily with Alcohol ; of attracting distilled Oils, as well as those procured by Pression ; and of attracting Acids of all kinds, tho' some more than others. Add, that the Power of Alcali, as a Menftruum, has its Bounds, for that it has no Effect upon pure Quickfilver, nor even upon the purer Metals, as Gold and Silver.

The Author fubjoins several Problems, or Points of Inquiry concerning Alcalies ; as, whether it be possible for any Alcali to remain long in the Air, without losing its al. caline Characters; and whether it will not al. ways, by its meeting with acid or oily Bodies therein, turn into a neutral Salt, or a Sapo? Whether the same does not happen in the Bodies of Plants, or Animals; and whe- ' ther hence does not every day arise a great Quantity of compound Salts, &c.

The second Class of faline Menstruums are Volatile volatilé Alcalies, usually supposed to owe their Alcalies. origin' to the Putrifačtion, or Distillation of P. o vegetable and animal Bodies. The Powers and Properties of these are much the same as those of the fixed Kind; except that they | No. XVI. 1732. Cc

VOL. III.

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act with a less D.gree of Heat, and that if the Fire be raised beyond a certain Point, they

evaporate, Acid, 804.

The third Class consists of acid Menstruums,

! ne ipira las coni which are rarely found in a solid Form, except in the effential Sale of four Plants, or Tartar. Whether there be any in Animals, is disputed ; as also, whether those in Vegetables be native, or produced therein by Fermentation? At least, Fermentation appears greatly to promote the occulc Acid lodged in

Vegetables. Kinds.

The Acids produced by Fementation, are divided by the Author into Vinose and Acetose; which latter are of such importance in Chee mistry, that all Menftruums are frequently called by the Name of Aceta Philofophorum. Again, foffil Acids, proper for dissolving Gold, Silver, &c. are either native, which are very rare ; or fixed, as chofe found in Sulphur, Alom, Vitriol, Nitre, and Sea-Salt. --- From the whole, the Author deduces several Corollaries concerning the Nature of different Menftruums ; and shews more particularly their Agreement and Disagreement, both with them

felves, and with Alcalies. Neutral. The fourth Class consists of neutral faline

Menstruums; such are Sal Ammoniac, Sea-Salt, Salt-perre, Borax, and divers other compound Salts, the menstrual Properties and Effects of each whereof, the Author shews ac large ; closing the Chapter with a Number of Corollaries concerning the Powers, Properties, and, Action of Menftruums ; wherein he liquidates mány Points, starts divers new Views and Hints, from the Facts delivered in the course

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thafuitain the F Either the Matter is estats, solvinge is considere potters Earth, veniencies:

For the universal Menstruum or Alcahest, Alcaheft. the Author makes a particular Article ; wherein P. 848. he gives its History at large ; deducing its Name, Etymon, Synonima's, Origin, Powers, Manner of Aition, and Effets ; Immutability, and Volatility. Inquires into the Matter of which the Alcahest is to be made, viz. whether SeaSalt, the B:lsis of the Sal Circulatum minus ; or Mercury, the Basis of the Sal Circulatum majus; or fome Metal or Earth.

The Theory ends with an account of the chemical Furniture of Vessels and Utensils. In the Vessels the Conditions required are ; velels: that they be fit to contain the Object, ando to sustain the Force, of Fire, and other difsolving Agents. Either the Matter or Form of these is considered. The Matter is either Wood or Stone, or Potters Earth, or Glass, which last has extraordinary Conveniencies: for the Figure, it is various, according to the uses; and may be reduced to the two Heads of cylindrical Vessels, which rarely come in use, and conical ones: in which latter, some have the Figure of the Cone ereit, used to hinder the ascent of the Bodies exposed to the Fire; others have it inverted, or placed on its Vertex, used in separating the fixed Parts of Bodies from the lighter and more volatile. The Principles both of Geometry and Hydraulicks, on which these different Structures depend, are explained by the Author ; as alla the several Instruments themselves, viz. the Retort, Cucurbit, Matrass, Long-neck, Receiver, Alembic, Pelican, &c.

He proceeds to consider Lutes, or so thatLutes. 881. 66 tenacious sort of Bodies, which grow folid as " they dry, and serve for closing the functures

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