( ii °)

which did evidently prae-exist. But if the Hcrbs, are perfectly or intirelyTutrified, llttle or no Ale ah can be extracted from them ; as neither fromRotten or Tutrified Wood ; the Active Salti, by whose Combination the Al-calt isproduced, beingeither Expired or Evaporated.

Next, I am to enquire, How the Firc produces this Alcali: Whether bythe Changing of one single prx-existing Principlc ; or by enabling anyamong them to makeso notable an Alteration uponorin the other? orlast-ly, Whether it ia effected by the Union os two or more active Principies,which thereby become different from what they were before the saidCombination ?

I (hall not at present trouble you with the Reasons, Experiments, and Ob-lervations, which have indue’d me to reject the former z but, briefly sug-gest thofe, which incourage and difposc me to bclieve and Alsent to thelatter : So that this is my Position ; That Alcalt Salti do resuit from theCombination or Union of the Saline and Sulphureous Principle. But whetherit is the Volatile or Acid Salt , which Combines wich the Oyl of Sulphur , isnow the Subject of our Inquiry, The enfuing Considerations secm to de-termino in favour of the Acidi.

First, Tartar, which is sensibly Acid, and from which a Volati/e Sah can-not be Separated by any commonly known method, by bare Calcination be-comes a strong and perfect Alcali. Secondly, Nttre, an undoubted Acidwith a small proportion of Mineral or Vtgetable Sulphur, is converted intoa genuine fiery Alcali. Thirdly, Nitre, which is made by the A Ausion ofanAcid Spirit upon an Alcali, may be almost totaily Distilled into an AcidSpirit , there appearing not the least Footsteps of a Volattle Salt, andfcarce any of the Alcali, out of which it was chiefly produe’d.

But these are very weak and inconsiderable, compared wich Arguments,which neceslitate me to believe, that it Emerges from the Union of theVolatile Salt, with the Oleaginous or Sulphureous Principle. For,

x. There seems to be a great Contrariety between Acidi and Alcalies :Bcing mixt, they Heat, Fight, and Mortify each other; whatloever oneDiflolves, the other Precipitates : Whereas, were the Sah of Alcalies of anature approaching to Acidi, they would more plainly Unite without theviolent Contention, which ulually en sues.

2. Alcalies and Volatile Salti agree in most Properties, excepting theirDisterent Degrees of Gravitation. They are both Diurctical and De obstru-ent-, they boih Dissolve Sulphureous Bodits; agree in their Contrariety toAcids , but Mix together Quietly without Noise, Heat, Ebullition, or im-paring each orhers Vcrtues, and areeasily Separable; the fame in Quanti-ty and Quality they were before Mixture.

z. Tartareous or Estential Salti of Vegetables cannot become Alcalies , un-til their Acidtty bedriven away; during which Operation the Volatile Saltiand Oyl, Uniting, become more Ponderousthan the Acid, which before didGravitate more than eirher of them in their separate state: So that such a.Dfg»-eeofP;>e,aswill wholly Distipate the Acid Spirit ,cannot Elevate the morePonderous Alcali. Not but that, contrary to that which is commonly zf-*' ferted