ſuffic'd to make ſo great a quantity of Black Matter, ſhould reſort to ſo very ſmall a proportion of the Clarifying Liquor, (if I may ſo call it) as to be deluted by it, with out at all Denigrating it. And if it be ſaid that the Inſtill'd Liquor diſpers'd thoſe Black Corpuſcles, I demand, how that Diſperſion comes to deſtroy their Blackneſs, but by making ſuch a Local Motion of their parts, as deſtroys their former Texture? which may be a Matter of ſuch moment in caſes like ours, that I remember that I have in few houres, without addition, from Soot it ſelf, attain'd pretty ſtore of Cryſtalline Salt, and good ſtore of Tranſparent Liquor, and (which I have on another occaſion noted as remarkable) this ſo Black Subſtance had its Colour ſo alter'd, by the change of Texture it receiv'd from the fire, wherewith it was diſtill'd, that it did for a great while afford ſuch plenty of very white Exhalations, that the Receiver, though large, ſeem'd to be almoſt fill'd with Milk.
Secondly, But were it granted, as it is in ſome caſes not Improbable, that divers Bodies may receive a Blackneſs from a Sootie Exhalation, occaſion'd by the Aduſtion of their Sulphur, which (for the Reaſons lately mention'd I ſhould rather call their Oyly parts;) yet ſtill this account
is applicable but to ſome Particular Bodies, and will afford us no General Theory of Blackneſs. For if, for example, White Harts-horn, being, in Veſſels well luted to each other, expos'd to the fire, be ſaid to turn Black by the Infection of its own Smoak, I think I may juſtly demand, what it is that makes the Smoak or Soot it ſelf Black, ſince no Such Colour, but its contrary, appear'd before in the Harts-horn? And with the ſame Reaſon, when we are told, that torrify'd Sulphur makes bodies Black, I deſire to be told alſo, why Torrefaction makes Sulphur it ſelf Black? nor will there be any Satisfactory Reaſon aſſign'd of theſe Quæries, without taking in thoſe Fertile as well as intelligible Mechanical Principles of the Poſition and Texture of the Minute parts of the body in reference to the Light and the Eye; and theſe applicable Principles may Serve the turn in many caſes, where the Aduſtion of Sulphur cannot be pretended; as in the appearing Blackneſs of an Open window, lookt upon at a ſomewhat remote diſtance from the houſe, as alſo in the Blackneſs Men think they ſee in the Holes that happen to be in White linnen, or Paper of the like Colour; and in the Increaſing Blackneſs immediatly Produc'd barely by ſo rubbing Velvet,
whoſe Piles were Inclin'd before, as to reduce them to a more Erected poſture, in which and in many other caſes formerly alleg'd, there appears nothing requiſite to the Production of the Blackneſs, but the hindering of the incident Beams of Light from rebounding plentifully enough to the Eye. To be ſhort, thoſe I reaſon with, do concerning Blackneſs, what the Chymiſts are wont alſo to do concerning other Qualities, namely to content themſelves to tell us, in what Ingredient of a Mixt Body, the Quality enquir'd after, does reſide, inſtead of explicating the Nature of it, which (to borrow a compariſon from their own Laboratories) is much as if in an enquiry after the cauſe of Salivation, they ſhould think it enough to tell us, that the ſeveral Kinds of Præcipitates of Gold and Mercury) as likewiſe of Quick-ſilver and Silver (for I know that make and uſe of ſuch Precipitates alſo) do Salivate upon the account of the Mercury, which though Diſguis'd abounds in them, whereas the Difficulty is as much to know upon what account Mercury it ſelf, rather than other Bodies, has that power of working by Salivation. Which I ſay not, as though it were not ſomething (and too often the moſt we can arrive at) to diſcover in which of the
Ingredients of a Compounded Body, the Quality, whoſe Nature is ſought, reſides, but becauſe, though this Diſcovery it ſelf may paſs for ſomething, and is oftentimes more than what is taught us about the ſame ſubjects in the Schools, yet we ought not to think it enough, when more Clear and Particular accounts are to be had.
