Page:Cyclopaedia, Chambers - Volume 2.djvu/667

 SAL

SALLY, in Architecture, irom the French Sallie, is what wc more uiiially call l J>roje£litre, See Projec- tive.

Sally, in the Military Art, the iffuing out of the Befieged from their Town or Fort, and falling upon the Beiiegers to cut them off, nail their Cannon, hinder the Progreis of their Approaches, deitroy their Works, &c. To Cut off a Sally, is to get between thole who made it and the Town.

SALON, or Saloon, in Architecture, a very lofty, fpa- cious Hall, vaulted at Top, and ibmctimes comprehend- ing two Stories, or Ranges, of Windows ; As that at gtevfoeim-Houie. The Salon is a Grand Room in the Middle of a Building, or at the Head of a Gallery, $§c\ Its Faces, or Sides, are all to have a Symmetry with each other ; and as it ulually takes up the Height of two Stories, its Ceiling, Davikr obferves, mould be with a moderate Sweep. '1 he Salon is a State Room. 'Tis much ufed in the Palaces in Italy j and from thence the Mode came to us. Embaffadors, and other Great Vic- tors, are ulually received in the Salon : 'Tis frequently built Square, lomenmes Odogonal, as at Marly, and ibmetimes in other Forms.

SALT, Sal, in Chymiitry, a fimple, acid Subftance which enters the Compofition of all Bodies, and is held one of the Five 'Principles, or Elements thereof; only to be extracted by Fire. See Principle. Salt, M. Hom- berg obferves, is an Ingredient in all Animal, Vegetable, and Mineral Bodies, excepting perhaps fome Metals, and Stones. In Vegetables and Mineral Bodies, that have un- dergone a Fermentation, the Salt riles firft in the Alembic, then the Phlegm : If the Mixt have undergone a Fer- mentation, the Salt riles after the Phlegm.

Salts are diftinguifhed, with Regard to the Manner of extracting them, $c. into Volatile, Fixed, and EJJential. Volatile Salts, are thofe light, fubtle ones, which rile eafily upon Diftilladon, or are even exhaled by the Noft, and rendered feniible to the Smell. See Volatile Saht. Fixed Salts are l'uch as, being more Grols and Material, refill and fuftain the Fire ; and are not railed by it, but remain, after Calcination, or Diitilladon, in the Earthy Part, at the Bottom. For the Manner of Extract- ing them, ^c. fee Fixed Salt. Bjfential Salts are thofe drawn from Vegetables, without the Ufe of Fire, as by Crystallization, and other eafy, natural Means. See Essential Salts. Volatile Salts become diflinguifha- ble to the Nofe, Tongue, and Brain, by their Tenuity and Brisknels ; Fixed Salts by their Bitternels, and Heat in the Mouth. To thefe may be added an intermediate Kind of Salt, under the Title of Mixed Salts j which are thole refulting from a Mixture of a Volatile with Fixed Salt.

Salts are of different Kinds, according to the diffe- rent Matters wherewith they are found mixed ; Some are mix'd Bodies themielves, and their Mixture feparable by Fire, and Lixivation ; fuch are all EJJential Salts of Plants, and all FofJUe Salts, &c. but thele are no proper Chymical Principles. There are others which we are ien- fiblc are mixed, and whofe Mixture we know pretty near- ly, though we are not yet able to decompound them : "Tis thele make the Chymical Principle Salt ; for our Analyfes will not render them more Simple, which is the Character of a Principle : And in this Senfe Salt is de- lined, A Matter dijfoluable by Water, and unchangeable by Fire; to which lome add, Ofapw?ge?2t c /aJle.

There are Three Kinds, or Claffes, .of Salts, which come under this Definition ; Two whereof are Volatile, and the Third Fixed. The Volatile ones, are Acid Salts, and Urinous Salts $ the Fixed, are thofe drawn by a Lixi- vium after Calcination, and called Lixivious Salts. Na- ture produces none of thele Salts limple and unmixed, but we eafily extract them by Art, from the Mixts where- in fhe has placed them. The Principal Natural Salts may be reduced to Salt-petre, Sea-Salt, and Vitriol. Each whereof has its different Kinds ; of the various Combination whereof, with different Oily Matters, all the Natural Salts, we know of, are compounded. Thefe Salts are found, by Chymical Analyfes, to conlift of Aqueous, Earthy, Oily, or Sulphurous, and Acid Parti- cles. The Acid Matter is the 'Pure Salt, or the Salt-  and is the Bafe of all the reft. This M. Jiom- berg obferves, is pretty uniform, and nearly the lame in all Salts, before the particular Determination to form this or that Salt, by the particular Admixture of the Sul- phur, ££c. Saltpetre, Sea-Salt, &c therefore are not Principles, but the Acid Salts diftilled from them are, and the Water wherein thefe Salts fwim, and the Earth, or Fixed Salt, remaining in the Retort after Diftilla- tion, are other Chymical Principles. See Phlegm, and Earth,

The Principle Salt is held a Mean between the Active and TaJJfoe Principles. The pure Acid, though accom-

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SAL

panied with its fulphurous determinating Matter, never becomes ienfible but when lodged either in ibme earthy Matter, or artificially in lbme fimple aqueous Matter. In the firft Cafe, it appears under the Form of a cryftal- lized Salt, as Saltpetre, £J?c. See Salt, £sfc. In the fecond Gale, it appears in the Form of an Acid Spirir, which, according to the Determination of the Sulphur that accompanies it, is either Spirit ofNitre, orSpirit ot Common- Salt, or Spiric of Vitriol ; and what we have here obierved of the three Simple, or FoJJile Salts, may be applied to all other more Compound Salts of Plants, Animals, tfc. with this Difference, That when, in Form of a Concrete Salt, thefe lafl always take a greater Quantity of earthy Mat- ter, and when in Form of an Acid Spirit, a greater Quan- tity of aqueous Matter, than the Simple ones. Whence it follows, that the Acid Spirits of Compound Salts are always weaker, lighter, and lefs penetrating than thofe of FoJJile Salts ; and after Diflillation leave a'greater Quan- tity of earthy Matter behind them.

We don't know precifely what Figures the three Salt- principles, Acid, Urinal, and Lixivial, muft have. But to judge by their Effects, one would conclude, the Acids to be pointed, only the Points fhearhed in fome fulphu- rous Matter. The Urinous Salts to be Spunges, contain- ing fome of the Acid, and fome of the fcetid Oil of the Animal or Plant : And the Lixivious Salts to be Spunges, only containing the Remainder of the Acid, which the calcining Fire could not expel.

Acid Spirits may be conceived as pure, and without any Mixture ; in which Cafe all Acids will be found of the fame Nature : But if we confider them as Diflilla- tion gives them, we fhall always find them accompanied with ibme fulphurous Matter, which we cannot fepa- rate from them, and which gives the Degree of Activity to the Acid Spirits. 'Tis this fulphurous Matter which characterizes them, and makes all the Difference we find between Acid Spirits. M. Homberg ranges all the Kinds of Acid Spirits under Three different Claffes, according to the different fulphurous Matters which accompany them. The Firft Oafs is of thofe which contained Animal or Vegetable Sulphur ; under which come all Acids, di- flilled from Plants, Fruits, Woods, S?c. as alfo Spirit of Nitre. 'Tis eafy to conceive, that the Acids of Plants may have retained a Part of the Oil of *he Plant, which is their Sulphur ; fince in reducing thefe Acids into Salts, we always find a little Oil therein ; which can be nothing elfe but that of the Plants themielves. And for Salt- fetre, as this is always drawn from Earths moiftened with the Excrements of Animals, or from old Walls, Plai- ner, tfc. full of the fulphurous Matters of the Animals that lived within ihem, the Soot, &c. 'tis thence, doubt- lefs, Salt-petre borrows its Sulphur. See Salt-Petre. The Second Clafs is pf thofe wnich contain a bituminous Sulphur : Under which come the Acids of Vitriol, Com- mon Sulphur, and Alum. For thofe are all ufually drawn from the fame Mineral Stone, wherein the bi- tuminous Matter, which makes one of the Principal Parts of Common Sulphur, predominates. See Sulphur. Th» Third Clafs is of thofe which contain a more fixed mi- neral, fulphurous Matter; approaching nearer the Pro- perties of Metaline Sulphur : Under which Ckfs come the Acids drawn from fcveral Kinds of Sea Salts, Rcck- Salts, &c. For the Rock Salt, or Sal-Gemmae, is always found in Places near Metalic Mines ; and Sea-Salt, in all Appearance, is nothing but Rock Salt, the Quarries where- of have been penetrated by the Sea- Water, which has extracted all the Saltnefs therefrom. See Sea-Salt.

The fulphurous Matters of the Firft Clafs of Acids be- ing very light, and taking up a deal of Place, muft aug- ment the Bulk of the Points of the Acids to which they are joined. And hence theft Acids become difabled from penetrating vety compaa Bodies; but their Surface be- ing increafed from the fame Caufe, the Flame will have the greater Hold to drive them : And hence the Acids of this Clafs aft more fwiftly than any of the reft. The bituminous Sulphur is rhe leaft aftive of all the Sulphurs we know, as being leaden with a great Quantity of earthy Matter, which ferves it as a Matrix. Hence it unites more difficultly with Siline Matters than any of the other Sulphurs; fo that a lefs Quantity of it may be conceived to adhere to the Acids of this, than of either of the other Claffes. Accordingly we find, that the Acids of this Clafs, ufed alone, fcarce diffolve any Metals; but mixed with the others, partake of their Sulphur, and thereby become enabled to diffolve all Metals. The Metalick- Sulphur is of all others the moft fixed ; that is, its Parts are the fmalleft, and moft compact. See Fixity. Hence the Points of this Clafs of Acids will not be much fwelled by it, and of Conftquence will be able to infinuate them- felves into the moft compact Bodies, or thofe whofe Pores are the fmalleft. And for the fame Reafon they will not give much hold to the Flame that agitates them, and will

thetefore