General Biflory o/DRUGGS.

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The Fourth is, That the Sea Salt muft ne-ceffarily be made in the Land j for if but ali'tle vers'd in Chymiftry, one may knowthat fix'dSalt compos'd of an acid Earth, asthe Sea Salt is, cou'd never be evaporated,or perfected in the Sea Water ; it wants theEarth to imbody the acid Liquor, otherwifeit wou'd always remain a fluid Salt, and ne-ver become folid. If we make a chymicalAna'yfis of Sea Salt, one may draw fromthence a great deal of acid Liquor, whichbeing feparated from the Earth can nevergain again its Confidence of Salt. This Ar-gument being clear and demonftrative, it islikewife plain, that the Sea Salt muft re-ceive its Elaboration in the Earth before it isconvey'd into the Sea : But as we fee noSalt fo plentiful in the Earth as Sal Gem,we may well believe it is that which givesa Saltnefs to the Sea; befides the Salt thatwe now take from the Sea is entirely like itin Tafte, in Quality, and in Principles.

But I (hall propoie fome Objections madeagainft this; they lay that it is difficult toconceive that the Sea which is fo large, andof fo prodigious an Extent, fhou'd receive allits Saltnefs from Sal Gem ■ for tho' there isgreat Quantities of Salt in the Bowels of theEarth, there does not appear enough to faitfo much Water.

To anfvver this Objection, I fay, that theDifficulty we apprehend of the Sal Gem'sbeing iufiicient to laic the Sea, proceeds fromthis, that we do not fee the Quantity ofSalt Mines, as we do the Extenfion of theSea Water : But if we confider that theEarth is full of Sal Gem, or the like, inMillions of Places, and that it difchargesitfelf into the Sea perpetually, there isno doubt but we may have Room tocomprehend that the Earth in all its Parts,contains Salt enough in it to make the SeaSalt.

Another Objection they bring is, that ac-cording to my Argument the Sea ought eve-ry Day to encreafe in Saltnefs, fince it per-petually receives frefh Salt, which cannot bedifpos'd of otherwife : I anfwer, that we can-not perceive any Augmentation of the Sea'sSaltnefs ; for if there be a great deal ofSalt that is brought into it, there is likewifea great Confumption by Evaporation and theMotion of the Waves that are driven with

Vol. IL

fuch Rapidity and Violence, that they vola-tilize a great Share of Salt that is receiv'd inVapour, as may be fenfibly perceiv'd by thefalc Air we breath in, when upon the Sea,and which contributes much with the Agita-tion of the Ship towards the Provocation toVomiting. This Salt is driven by the Windsupon the Shore, where it is ufeful to makethe Land fertile, and by a perpetual Circu-lation it is brought to the Sea again.

In Normandy they make Sea Salt by Eva-porating Sea Water over the Fire in greatleaden Cauldrons to a Drynefs j there re-mains a white Salt that is lefs piquant and lefsfait than that of UpcheUe, becaufe of the Eva-poration, and perhaps occafion'd from fomeParticles of Lead that are diffolv'd in it,which has blunted its Points ; this Kind ofSalt lofes its Strength as it increafes in Age.

There is a Salt prepar'd by Cryftallizationat Broiiags and i\ochelle, befides feveral otherParts of the Country where there are faitLake;. The Rgchelle Sale is grey becaufe ofa little Earth that it carries along with it; itis nevenhelefs more penetrating, and falterthan the white Normandy Salt, which is madeby Evaporation, but it is not fo piquant asSal Gem, becaufe of the violent Motion ofthe Sea Waves which blunts its finer Points.It may be render'd white as Sugar, by dif-folving in Water, filtrating the Diffolurion,and Evaporating to a Drynefs : But as inthis Purification we feparate it from a greatdeal of Earth, which made it weaker ; itdoes not by this Means increafe its Strength,but on the contrary it is lefs biting, becaufethat the Fire hascarry'd off, or blunted feve-ral of its more fubtile Points. Sea Salt con-tains a great deal of Acid, a fmall Quantityof Sulphur and Earth ; it is incifive, pene-trating , deficcative, aperitive, relolutive;it is us'd in Apoplexies and Convulfions ;they mix it in Baths and Suppofitories, andbeing apply'd hot behind the Neck ; it rari-fies and diffipates Catarrhs.

14. Of Nitre or Saltpetre.

CAltfetre, which the Chymifts call

Dragon, Cerberus, or the Infernal

Salt, is an artificial or factitious Salt,

drawn from feveral Sorts of

Pomet.

Materials, asfrom