Sed. 15.

Of Precipitation.

47

ther, the Salts, with which they a-bound, being put into motion bytheir attractive Force, run mutuallytowards one another; and becaufethey don't recoil far back after the

ner, Water, Vinegar, &c. make a

Precipitation from Acids, tho more

fparingly. Nay, Acids themièlves

being poured upon others, which are

heavier, will precipua: e whatever is

fwimming in them. Thus Spirit of Shock, they are at length fo united,

Salt precipitates either Lead, Copper, as to become like a Solid, there

being very little Phlegm remaining.The fame may likewilé be obferv'din Tartarian Vitriolatum. In ma-king all thefe Experiments, therehappens fuch a Conflict and Effer-vefcence, as evaporates almoft allthe Moifture with which the Saltsare diluted. And upon this dependsthe Rationale of Chymical Coagula-tion, a thing of very great confe-rence in the bufinefs of Precipi-tation. Nor can we account for Oilof Tartar's precipitating Bodies dif-iolv'd in Acids, any otherwife thanfiom its making a kind of Coagu-lar» with thefe Co r pufcles, whichthereby becomes too heavy for,and exceeds the Tenacity of theMenflruum.

Nor does Coagulation fucceed.only upon the mixing of heavierFluids, but it alio very often pro-motes Precipitation, when the Gra-vity of the inftill'd Liquor is entirely-equal to that of the Menflruum,or but very little different from it.And this Agglutination of Parts is tobe feen in many Liquors, but moftof all infalineones. Thus Spirit ofSal Armoniac, Spirit of Hartfliorn,that of Human I lood, and Sal Vo-latile Oleofum, whole Gravities arenearly the lame as that of commonWater, precipitate the RelblutionoiSublimate very plentifully, as youmay obferve in making the WhitePrecipitate of Mercury. In whichExperiment, the Increafe of theWeight gives a fufficient Indicationof an Union of thofe Salts, whichare pretty copious in the Sublimate,and Liquors which are pour'd upon

or Tin, diflblv'd in Oil of Vitriol,So little need there is for Alcali's inthis bufinefs, tho all the Chjmiftshave unanimoufly contended torthem as absolutely neceflary.

In tne lêcond place, Precipitationwill iucceed as well, if there oe ad-died a heavier Liquor to theAfe»-flruum. For the Particles of thisLiquor, what with their Weight,and wha" with the Impetus they ac-quire in their Défirent, carry downand link all the iblid Corpufcles theymeet with in their way. So that theCorpufcles being thus fbic'd down,and kept there cy this adventitiousLiquor; cannon mount up into theirformer Situation. And if any onehas a mind to try the truth of thisRealbmng by Experiments, thereare enougn to confirm it: For notonly arid Spirits, but Water alcne,will precipitate Tinâures of Vege-tables extracted by Spirit of Wine.And the very fame Tinétures, ex-tracted with Water 01 Wine, are pre-cipitated very copioufly by acid Spi-rits, which are heavier. Afterthismanner, Metals which are diiTolv'din Spirit of Sal Armoniac, are pre-cipitated with Oil of Vitriol, or Spi-rit of Nitre. The fame Bodies, thoiüípendedin Aqua Tortis, are eafilyprecipitated with Oil of Vitriol, orEezoartic Spirit of Nitre. And thisvery Oil, if poured upon Sal Vola-tile Oleofum, or any other Solutionof Salt, ever io much faturated,does not only fink the fmaller Par-ticles, but converts almoft the wholeLiquor into Salt. For when thefeLiquors are pour'd upon one aco-