Experiments and Considerations Touching Colours (1664) - Part 8
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Part 8

[22] _Beguinus_, Tyr. Chy. Lib. 2. Cap. 13.

_EXPERIMENT XLIII._

We took good common Vitriol, and having beaten it to Powder, and put it into a Crucible, we kept it melted in a gentle heat, till by the Evaporation of some parts, and the shuffling of the rest, it had quite lost its former Colour, what remain'd we took out, and found it to be a friable _Calx_, of a dirty Gray. On this we pour'd fair Water, which it did not Colour Green or Blew, but only seem'd to make a muddy mixture with it, then stopping the Vial wherein the Ingredients were put, we let it stand in a quiet place for some dayes, and after many hours the water having dissolv'd a good part of the imperfectly calcin'd Body, the Vitriolate Corpuscles swiming to and fro in the Liquor, had time by their opportune Occursions to const.i.tute many little Ma.s.ses of Vitriol, which gave the water they impregnated a fair Vitriolate Colour; and this Liquor being pour'd off, the remaining dirty Powder did in process of time communicate the like Colour, but not so deep, to a second parcel of cleer Water that we pour'd on it.

But this Experiment _Pyrophilus_ is, (to give you that hint by the way) of too Luciferous a Nature to be fit to be fully prosecuted, now that I am in haste, and willing to dispatch what remains. And we have already said of it, as much as is requisite to our present purpose.

_EXPERIMENT XLIV._

It may (_Pyrophilus_) somewhat contribute towards the shewing how much some Colours depend upon the less or greater mixture, and (as it were,) Contemperation of the Light with shades, to observe, how that sometimes the number of Particles, of the same Colour, receiv'd into the Pores of a Liquor, or swiming up and down in it, do seem much to vary the Colour of it. I could here present you with particular instances to show, how in many (if not most) consistent Bodyes, if the Colour be not a Light one, as White, Yellow, or the like, the closeness of parts in the Pigments makes it look Blackish, though when it is display'd and laid on thinly, it will perhaps appear to be either Blew, or Green, or Red. But the Colours of consistent Pigments, not being those which the Preamble of this Experiment has lead you to expect Examples in, I shall take the instances I am now to give you, rather from Liquors than Dry Bodyes. If then you put a little fair Water into a cleer and slender Vial, (or rather into one of those pipes of Gla.s.s, which we shall by and by mention;) and let fall into it a few drops of a strong Decoction or Infusion of _Cochineel_, or (for want of that) of _Brazil_; you may see the tincted drops descend like little Clouds into the Liquor; through which, if, by shaking the Vial, you diffuse them, they will turn the water either of a Pinck Colour, or like that which is wont to be made by the washing of raw flesh in fair Water; by dropping a little more of the Decoction, you may heighten the Colour into a fine Red, almost like that which enn.o.bles Rubies; by continuing the affusion, you may bring the Liquor to a kind of a Crimson, and afterwards to a Dark and Opacous Redness, somewhat like that of Clotted Blood. And in the pa.s.sage of the Liquor from one of these Colours to the other, you may observe, if you consider it attentively, divers other less noted Colours belonging to Red, to which it is not easie to give Names; especially considering how much the proportion of the Decoction to the fair Water, and the strength of that Decoction, together with that of the trajected Light and other Circ.u.mstances, may vary the Phaenomena of this Experiment. For the convenienter making whereof, we use instead of a Vial, any slender Pipe of Gla.s.s of about a foot or more in length, and about the thickness of a mans little finger; For, if leaving one end of this Pipe open, you Seal up the other Hermetically, (or at least stop it exquisitely with a Cork well fitted to it, and over-laid with hard Sealing Wax melted, and rubb'd upon it;) you shall have a Gla.s.s, wherein may be observ'd the Variations of the Colours of Liquors much better than in large Vials, and wherein Experiments of this Nature may be well made with very small quant.i.ties of Liquor. And if you please, you may in this Pipe produce variety of Colours in the various parts of the Liquor, and keep them swimming upon one another unmix'd for a good while. And some have marveil'd to see, what variety of Colours we have sometimes (but I confess rather by chance than skill) produc'd in those Gla.s.ses, by the bare infusion of Brazil, variously diluted with fair Water, and alter'd by the Infusion of several Chymical Spirits and other Saline Liquors devoid themselves of Colour, and when the whole Liquor is reduc'd to an Uniform degree of Colour, I have taken pleasure to make that very Liquor seem to be of Colours gradually differing, by filling with it Gla.s.ses of a Conical figure, (whether the Gla.s.s have its basis in the ordinary position, or turn'd upwards.) And yet you need not Gla.s.ses of an extraordinary shape to see an instance of what the vari'd mixture of Light and Shadow can do in the diversifying of the Colour. For if you take but a large round Vial, with a somewhat long and slender Neck, and filling it with our Red Infusion of Brazil, hold it against the Light, you will discern a notable Disparity betwixt the Colour of that part of the Liquor which is in the Body of the Vial, and that which is more pervious to the Light in the Neck. Nay, I remember, that I once had a Gla.s.s and a Blew Liquor (consisting chiefly (or only, if my memory deceive me not,) of a certain Solution of Verdigrease) so fitted for my purpose, that though in other Gla.s.ses the Experiment would not succeed, yet when that particular Gla.s.s was fill'd with that Solution, in the Body of the Vial it appear'd of a Lovely Blew, and in the neck, (where the Light did more dilute the Colour,) of a manifest Green; and though I suspected there might be some latent Yellowness in the substance of the neck of the Gla.s.s, which might with the Blew compose that Green, yet was I not satisfi'd my self with my Conjecture, but the thing seem'd odd to me, as well as to divers curious persons to whom it was shown. And I lately had a Broad piece of Gla.s.s, which being look'd on against the Light seem'd clear enough, and held from the Light appear'd very lightly discolour'd, and yet it was a piece knock'd off from a great lump of Gla.s.s, to which if we rejoyn'd it, where it had been broken off, the whole Ma.s.s was as green as Gra.s.s. And I have several times us'd Bottles and stopples that were both made (as those, I had them from a.s.sur'd me) of the very same Metall, and yet whilst the bottle appear'd but inclining towards a Green, the Stopple (by reason of its great thickness) was of so deep a Colour that you would hardly believe they could possibly be made of the same materials. But to satisfie some Ingenious Men, on another occasion, I provided my self of a flat Gla.s.s (which I yet have by me,) with which if I look against the Light with the Broad side obverted to the Eye, it appeares like a good ordinary window Gla.s.s; but if I turn the Edge of it to my Eye, and place my Eye in a convenient posture in reference to the Light, it may contend for deepness of Colour with an Emerald. And this Greeness puts me in mind of a certain thickish, but not consistent Pigment I have sometimes made, and can show you when you please, which being dropp'd on a piece of White Paper appears, where any quant.i.ty of it is fallen, of a somewhat Crimson Colour, but being with ones finger spread thinly on the Paper does presently exhibit a fair Green, which seems to proceed only from its disclosing its Colour upon the Extenuation of its Depth into Superficies, if the change be not somewhat help'd by the Colours degenerating upon one or other of the Accounts formerly mention'd. Let me add, that having made divers Tryals with that Blew substance, which in Painters shops is call'd _Litmase_, we have sometimes taken Pleasure to observe, that being dissolv'd in a due proportion of fair Water, the Solution either oppos'd to the Light, or dropp'd upon White paper, did appear of a deep Colour betwixt Crimson and Purple; and yet that being spread very thin on the Paper and suffer'd to dry on there, the Paper was wont to appear Stain'd of a Fine Blew. And to satisfie my selfe, that the diversity came not from the Paper, which one might suspect capable of inbibing the Liquor, and altering the Colour, I made the Tryal upon a flat piece of purely White Gla.s.s'd Earth, (which I sometimes make use of about Experiments of Colours) with an Event not unlike the former.

And now I speak of _Litma.s.s_, I will add, that having this very day taken a piece of it, that I had kept by me these several years, to make Tryals about Colours, and having let fall a few drops of the strong Infusion of it in fair water, into a fine Crystal Gla.s.s, shap'd like an inverted Cone, and almost full of fair Water, I had now (as formerly) the pleasure to see, and to show others, how these few tincted drops variously dispersing themselves through the Limpid Water, exhibited divers Colours, or varieties of Purple and Crimson. And when the Corpuscles of the Pigment seem'd to have equally diffus'd themselves through the whole Liquor, I then by putting two or three drops of Spirit of Salt, first made an odd change in the Colour of the Liquor, as well as a visible commotion among its small parts, and in a short time chang'd it wholly into a very Glorious Yellow, like that of a Topaz. After which if I let fall a few drops of the strong and heavy Solution of Pot-ashes, whose weight would quickly carry it to the sharp bottome of the Gla.s.s, there would soon appear four very pleasant and distinct Colours; Namely, a Bright, but Dilute Colour at the picked bottome of the Gla.s.s; a Purple, a little higher; a deep and glorious Crimson, (which Crimson seem'd to terminate the operation of the Salt upward) in the confines betwixt the Purple and the Yellow; and an Excellent Yellow, the same that before en.o.bled the whole Liquor, reaching from thence to the top of the Gla.s.s. And if I pleas'd to pour very gently a little Spirit of Sal Armoniack, upon the upper part of this Yellow, there would also be a Purple or a Crimson, or both, generated there, so that the unalter'd part of the Yellow Liquor appear'd intercepted betwixt the two Neighbouring Colours.

My scope in this 3d. Experiment (_Pyrophilus_) is manifold, as first to invite you to be wary in judging of the Colour of Liquors in such Gla.s.ses as are therein recommended to you, and consequently as much, if not more, when you imploy other Gla.s.ses. Secondly, That you may not think it strange, that I often content my self to rub upon a piece of White paper, the Juice of Bodies I would examine, since not onely I could not easily procure a sufficient Quant.i.ty of the juices of divers of them; but in several Cases the Tryals of the quant.i.ties of such Juices in Gla.s.ses would make us more lyable to mistakes, than the way that in those cases I have made use of.

Thirdly, I hope you will by these and divers other particulars deliver'd in this Treatise, be easily induc'd to think that I may have set down many Phaenomena very faithfully, and just as they appear'd to me, and yet by reason of some unheeded circ.u.mstance in the conditions of the matter, and in the degree of Light, or the manner of trying the Experiment, you may find some things to vary from the Relations I make of them. Lastly, I design'd to give you an opportunity to free your self from the amazement which possesses most Men, at the Tricks of those Mountebancks that are commonly call'd Water-drinkers. For though not only the vulgar, but ev'n many persons that are far above that Rank, have so much admir'd to see, a man after having drunk a great deal of fair water, to spurt it out again in the form of Claret Wine, Sack, and Milk, that they have suspected the intervening of Magick, or some forbidden means to effect what they conceived above the power of Art; yet having once by chance had occasion to oblige a Wanderer that made profession of that and other Jugling Tricks, I was easily confirm'd by his Ingenious confession to me, That this so much Admir'd Art, indeed consisted rather in a few Tricks, than in any great Skill, in altering the Nature and Colours of things. And I am easy to be perswaded; that there may be a great deal of Truth in a little Pamphlet Printed divers years ago in English, wherein the Author undertakes to discover, and that (if I mistake not) by the confession of some of the Complices themselves, That a famous Water-drinker then much Admir'd in _England_, perform'd his pretended Trans.m.u.tations of Liquors by the help of two or three inconsiderable preparations and mixtures of not un.o.bvious Liquors, and chiefly of an Infusion of Brazil variously diluted and made Pale or Yellowish, (and otherwise alter'd) with Vinegar, the rest of their work being perform'd by the shape of the Gla.s.ses, by Craft and Legerdemane.

And for my part, that which I marvel at in this business, is, the Drinkers being able to take down so much Water, and spout it out with that violence; though Custome and a Vomit seasonably taken before hand, may in some of them much facilitate the work. But as for the changes made in the Liquors, they were but few and slight in comparison of those, that the being conversant in Chymical Experiments, and dextrous in applying them to the Trans.m.u.ting of Colours, may easily enough enable a man to make, as ev'n what has been newly deliver'd in this, and the foregoing Experiment; especially if we add to it the things contained in the XX, the x.x.xIX and the XL. Experiments, may perhaps have already perswaded You.

_EXPERIMENT XLV._

You may I presume (_Pyrophilus_) have taken notice, that in this whole Treatise, I purposely decline (as far as I well can) the mentioning of Elaborate Chymical Experiments, for fear of frighting you by their tediousness and difficulty; but yet in confirmation of what I have been newly telling you about the possibility of Varying the Colours of Liquors, better than the Water-drinkers are wont to do, I shall add, that _Helmont_ used to make a preparation of Steel, which a very Ingenious Chymist, his Sons Friend, whom you know, sometimes employes for a succedaneum to the Spaw-waters, by Diluting this _Essentia Martis Liquida_ (as he calls it) with a due proportion of Water. Now that for which I mention to you this preparation, (which as he communicated to me, I know he will not refuse to _Pyrophilus_) is this, that though the Liquor (as I can shew you when you please) be almost of the Colour of a German (not an Oriental) Amethyst, and consequently remote enough from Green, yet a very few drops being let fall into a Large proportion of good Rhenish, or (in want of that) White Wine (which yet do's not quite so well) immediately turn'd the Liquor into a lovely Green, as I have not without delight shown several curious Persons.

By which _Phaenomenon_ you may learn, among other things, how requisite it is in Experiments about the changes of Colours heedfully to mind the Circ.u.mstances of them; for Water will not, as I have purposely try'd, concurr to the production of any such Green, nor did it give that Colour to moderate Spirit of Wine, wherein I purposely dissolv'd it, and Wine it self is a Liquor that few would suspect of being able to work suddenly any such change in a Metalline preparation of this Nature; and to satisfie my self that this new Colour proceeds rather from the peculiar Texture of the Wine, than from any greater Acidity, that Rhenish or White-wine (for that may not absurdly be suspected) has in comparison of Water; I purposely sharpen'd the Solution of this Essence in fair Water, with a good quant.i.ty of Spirit of Salt, notwithstanding which, the mixture acquir'd no Greenness. And to vary the Experiment a little, I try'd, that if into a Gla.s.s of Rhenish Wine made Green by this Essence, I dropp'd an Alcalizate Solution, or Urinous Spirit, the Wine would presently grow Turbid, and of an odd Dirty Colour; But if instead of dissolving the Essence in Wine, I dissolv'd it in fair Water sharpen'd perhaps with a little Spirit of Salt, then either the Urinous Spirit of Sal Armoniack, or the solution of the fix'd Salt of Pot-ashes would immediately turn it of a Yellowish Colour, the fix'd or Urinous Salt Precipitating the Vitriolate substance contain'd in the Essence. But here I must not forget to take notice of a circ.u.mstance that deserves to be compar'd with some part of the foregoing Experiment, for whereas our Essence imparts a Greenness to Wine, but not to Water, the Industrious _Olaus Wormius_[23] in his late _Musaeum_ tells us of a rare kind of Turn-Sole which he calls _Bezetta Rubra_ given him by an Apothecary that knew not how it was made, whose lovely Redness would be easily communicated to Water, if it were immers'd in it; but scarce to Wine, and not at all to Spirit of Wine, in which last circ.u.mstance it agrees with what I lately told you of our Essence, notwithstanding their disagreement in other particulars.

[23] Libr. 2do Cap. 34.

_EXPERIMENT XLVI._

We have often taken notice, as of a remarkable thing, that Metalls as they appear to the Eye, before they come to be farther alter'd by other Bodyes, do exhibit Colours very different from those which the Fire and the _Menstruum_, either apart, or both together, do produce in them; especially considering that these Metalline Bodyes are after all these disguises reducible not only to their former Metalline Consistence and other more radical properties, but to their Colour too, as if Nature had given divers Metalls to each of them a double Colour, an _External_, and an _Internal_; But though upon a more attentive Consideration of this difference of Colours, it seem'd probable to me, that divers (for I say not all) of those Colours which we have just now call'd _Internal_, are rather produc'd by the Coalition of Metalline Particles with those of the Salts, or other Bodyes employ'd to work on them, than by the bare alteration of the parts of the Metalls themselves: and though therefore we may call the obvious Colours, Natural or Common, & the others Advent.i.tious, yet because such changes of Colours, from whatsoever cause they be resolv'd to proceed may be properly enough taken in to ill.u.s.trate our present Subject, we shall not scruple to take notice of some of them, especially because there are among them such as are produc'd without the intervention of Saline _Menstruums_.

Of the Advent.i.tious Colours of Metalline Bodies the Chief sorts seem to be these three. The first, such Colours as are produc'd without other Additaments by the Action of the fire upon Metalls. The next such as emerge from the Coalition of Metalline Particles with those of some _Menstruum_ imploy'd to Corrode a Metall or Precipitate it; And the last, The Colours afforded by Metalline Bodyes either Colliquated with, or otherwise Penetrating into, other Bodies, especially fusible ones. But these (_Pyrophilus,_) are only as I told you, the _Chief_ sorts of the advent.i.tious Colours of Metalls, for there may others belong to them, of which I shall hereafter have occasion to take notice of some, and of which also there possibly may be others that I never took notice of.

And to begin with the first sort of Colours, 'tis well enough known to Chymists, that Tin being Calcin'd by fire alone is wont to afford a White _Calx_, and Lead Calcin'd by fire alone affords that most Common Red-Powder we call _Minium:_ Copper also Calcin'd _per se_, by a long or violent fire, is wont to yield (as far as I have had occasion to take notice of it) a very Dark or Blackish Powder; That Iron likewise may by the Action of Reverberated flames be turn'd into a Colour almost like that of Saffron, may be easily deduc'd from the Preparation of that Powder, which by reason of its Colour and of the Metall 'tis made of is by Chymists call'd, _Crocus Martis per se_. And that _Mercury_ made by the stress of Fire, may be turn'd into a Red Powder, which Chymists call Precipitate _per se_, I elsewhere more particularly declare.

_Annotation I._

It is not unworthy the Admonishing you, (_Pyrophilus_,) and it agrees very well with our Conjectures about the dependence of the change of a Body's Colour upon that of its Texture, that the same Metall may by the successive operation of the fire receive divers Advent.i.tious Colours, as is evident in Lead, which before it come to so deep a Colour as that of _Minium_, may pa.s.s through divers others.

_Annotation II_.

Not only the _Calces_, but the Gla.s.ses of Metalls, Vitrify'd _per se_, may be of Colours differing from the Natural or Obvious Colour of the Metall; as I have observ'd in the Gla.s.s of Lead, made by long exposing Crude Lead to a violent fire, and what I have observ'd about the Gla.s.s or Slagg of Copper, (of which I can show you some of an odd kind of Texture,) may be elsewhere more conveniently related. I have likewise seen a piece of very Dark Gla.s.s, which an Ingenious Artificer that show'd it me profess'd himself to have made of Silver alone by an extreme _Violence_ (which seems to be no more than is needfull) of the fire.

_Annotation III_.

Minerals also by the Action of the Fire may be brought to afford Colours very differing from their own, as I not long since noted to you about the variously Colour'd Flowers of Antimony, to which we may add the Whitish Grey-Colour of its _Calx_, and the Yellow or Reddish Colour of the Gla.s.s, where into that _Calx_ may be flux'd.

And I remember, that I elsewhere told you, that Vitriol Calcin'd with a very gentle heat, and afterwards with higher and higher degrees of it, may be made to pa.s.s through several Colours before it descends to a Dark Purplish Colour, whereto a strong fire is wont at length to reduce it. But to insist on the Colours produc'd by the Operation of fire upon several Minerals would take up farr more time than I have now to spare.

_EXPERIMENT XLVII._

The Advent.i.tious Colours produc'd upon Metalls, or rather with them, by Saline Liquors, are many of them so well known to Chymists, that I would not here mention them, but that besides a not un-needed Testimony, I can add something of my own, to what I shall repeat about them, and divers Experiments which are familiar to Chymists, are as yet unknown to the greatest part of Ingenious Men.

That Gold dissolv'd in _Aqua Regia_ enn.o.bles the _Menstruum_ with its own Colour, is a thing that you cannot (_Pyrophilus_,) but have often seen. The Solutions of Mercury in _Aqua-fortis_ are not generally taken notice of, to give any notable Tincture to the _Menstruum_; but sometimes when the Liquor first falls upon the Quick Silver, I have observ'd a very remarkable, though not durable, Greenness, or Blewness to be produc'd, which is a _Phaenomenon_ not unfit for you to consider, though I have not now the leisure to discourse upon it. Tin Corroded by _Aqua-fortis_ till the _Menstruum_ will work no farther on it, becomes exceeding White, but as we elsewhere note, does very easily of it self acquire the consistence, not of a Metalline _Calx_, but of a Coagulated matter, which we have observ'd with pleasure to look so like, either to curdled Milk, or curdled Whites of Eggs, that a person unacquainted with such Solutions may easily be mistaken in it. But when I purposely prepar'd a _Menstruum_ that would dissolve it as _Aqua-fortis_ dissolves Silver, and not barely Corrode it, and quickly let it fall again, I remember not that I took notice of any particular Colour in the Solution, as if the more Whitish Metalls did not much Tinge their _Menstruums_, though the conspicuously Colour'd Metalls as Gold, and Copper, do. For Lead dissolv'd in Spirit of Vinegar or _Aqua-fortis_ gives a Solution cleer enough, and if the _Menstruum_ be abstracted appears either Diaphanous or White. Of the Colour of Iron we have elsewhere said something: And 'tis worth noting, that though if that Metall be dissolv'd in oyl of Vitriol diluted with water, it affords a Salt or Magistery so like in colour, as well as some other Qualities, to other green Vitriol, that Chymists do not improperly call it _Vitriolum Martis_; yet I have purposely try'd, that, by changing the _Menstruum_, and pouring upon the filings of Steel, instead of oyl of Vitriol, _Aqua Fortis_, (whereof as I remember, I us'd 4 parts to one of the Metall) I obtain'd not a Green, but a Saffron Colour Solution; or rather a thick Liquor of a deep but yellowish Red. Common Silver, such as is to be met with in Coines, being dissolv'd in _Aqua fortis_, yields a Solution tincted like that of Copper, which is not to be wondred at, because in the coining of Silver, they are wont (as we elsewhere particularly inform you) to give it an Allay of Copper, and that which is sold in shops for refined silver, is not (so far as we have tryed) so perfectly free from that ign.o.bler Metall, but that a Solution of It in _Aqua fortis_, will give a Venereal Tincture to the _Menstruum_. But we could not observe upon the solution of some Silver, which was perfectly refin'd, (such as some that we have, from which 8 or 10 times its weight of Lead has been blown off) that the _Menstruum_ though held against the Light in a Crystal Vial did manifestly disclose any Tincture, only it seem'd sometimes not to be quite dest.i.tute of a little, but very faint Blewishness.

But here I must take notice, that of all the Metalls, there is not any which doth so easily and constantly disclose its un.o.bvious colour as Copper doth. For not only in acid _Menstruums_ as _Aqua Fortis_ and Spirit of Vinegar, it gives a Blewish green solution, but if it be almost any way corroded, it _appears of one of those_ two colours, as may be observ'd in Verdigreese made several wayes, in that odd preparation of _Venus_, which we elsewhere teach you to make with Sublimate, and in the common Vitriols of _Venus_ deliver'd by Chymists; and so constant is the disposition of Copper, notwithstanding the disguise Artists put upon it, to disclose the colour we have been mentioning, that we have by forcing it up with _Sal Armoniack_ obtain'd a Sublimate of a Blewish Colour. Nay a famous Spagyrist affirms, that the very Mercury of it is green, but till he teach us an intelligible way of making such a Mercury, we must content ourselves to inform you, that we have had a Cupreous Body, that was Praecipitated out of a distill'd Liquor, that seem'd to be the the Sulphur of _Venus_, and seem'd even when flaming, of a Greenish Colour. And indeed Copper is a Metall so easily wrought upon by Liquors of several kinds, that I should tell you, I know not any Mineral, that will concurr to the production of such a variety of Colours as Copper dissol'd in several _Menstruums_, as Spirit of Vinegar, _Aqua fortis_, _Aqua Regis_, Spirit of Nitre, of Urine, of Soot, Oyls of several kinds, and I know not how many other Liquors, if the variety of somewhat differing colours (that Copper will be made to a.s.sume, as it is wrought upon by several Liquors) were not comprehended within the Limits of Greenish Blew, or Blewish Green.

And yet I must advertise you (_Pyrophilus_) that being desirous to try if I could not make with crude Copper a Green Solution without the Blewishness that is wont to accompany its Vulgar Solutions, I bethought my self of using two _Menstruums_, which I had not known imploy'd to work on this Metall, and which I had certain Reasons to make Tryal of, as I successfully did. The one of these Liquors (if I much misremember not) was Spirit of Sugar distill'd in a Retort, which must be warily done, (if you will avoid breaking your gla.s.ses) and the other, Oyl or Spirit of Turpentine, which affords a fine Green Solution that is useful to me on several occasions.

And yet to shew that the advent.i.tious colour may result, as well from the true and permanent Copper it self, as the Salts wherewith 'tis corroded, I shall add, that if you take a piece of good _Dantzick_ Copperis, or any other Vitriol wherein _Venus_ is praedominant, and having moistened it in your Mouth, or with fair water, rubb it upon a whetted knife, or any other bright piece of Steel or Iron, it will (as we have formerly told you) present'y stain the Steel with a Reddish colour, like that of Copper, the reason of which, we must not now stay to inquire.

_Annotation I._

I presume you may have taken notice (_Pyrophilus_) that I have borrowed some of the Instances mention'd in this 47th Experiment, from the Laboratories of Chymists, and because in some (though very few) other pa.s.sages of this Essay, I have likewise made use of Experiments mention'd also by some Spagyrical Writers, I think it not amiss to represent to you on this Occasion once for all, some things besides those which I intimated in the praeamble of this present Experiment; For besides, that 'tis very allowable for a Writer to repeat an Experiment which he invented not, in case he improve it; And besides that many Experiments familiar to Chymists are unknown to the generality of Learned Men, who either never read Chymical processes, or never understood their meaning, or never durst believe them; besides these things, I say, I shall represent, That, as to the few Experiments I have borrowed from the Chymists, if they be very Vulgar, 'twould perhaps be difficult to ascribe each of them its own Author, and 'tis more than the generality of Chymists themselves can do: and if they be not of very known and familiar practise among them, unless the Authors wherein I found them had given me cause to believe, themselves had try'd them, I know not why I might not set them down, as a part of the _Phaenomena_ of Colours which I present you; Many things unanimously enough deliver'd as matters of fact by (I know not how many Chymical Writers) being not to be rely'd on, upon the single Authority of such Authors: For Instance, as some Spagyrists deliver (perhaps amongst several deceitful processes) that _Saccarum Saturni_ with Spirit of Turpentine will afford a Balsom, so _Beguinus_ and many more tell us, that the same Concrete (_Saccarum Saturni_) will yield an incomparably fragrant Spirit, and a pretty Quant.i.ty of two several Oyles, and yet since many have complain'd, as well as I have done, that they could find no such odoriferous, but rather an ill-sented Liquor, and scarce any oyl in their Distillation of that sweet Vitriol, a wary person would as little build any thing on what they say of the former Experiment, as upon what they averr of the later, and therefore I scrupled not to mention this Red Balsom of which I have not seen any, (but what I made) among my other experiments about redness.

_Annot. II._

We have sometimes had the Curiosity to try what Colours Minerals, as Tingla.s.s, Antimony, Spelter, &c. would yield in several _Menstruums_, nor have we forborn to try the Colours of stones, of which that famous one, (which _Helmont_ calls _Paracelsus's Ludus_) though it be digg'd out of the Earth and seem a true stone, has afforded in _Menstruums_ capable to dissolve so solid a stone, sometimes a Yellowish, sometimes a Red solution of both which I can show you. But though I have from Minerals obtain'd with several _Menstruums_ very differing Colours, and some such as perhaps you would be surpriz'd to see drawn from such Bodies: yet I must now pa.s.s by the particulars, being desirous to put an End to this Treatise, before I put an end to your Patience and my own.

_Annotation III._

And yet before I pa.s.s to the next Experiment, I must put you in mind, that the Colours of Metals may in many cases be further alter'd by imploying, either praecipitating Salts, or other convenient Substances to act upon their Solutions. Of this you may remember, that I have given you several Instances already, to which may be added such as these, That if Quicksilver be dissolv'd in _Aqua fortis_, and Praecipitated out of the Solution, either with water impregnated with Sea salt, or with the spirit of that Concrete, it falls to the Bottom in the form of a white powder, whereas if it be Praecipitated with an Alcaly, it will afford a Yellowish or tawny powder, and if there be no Praecipitation made, and the _Menstruum_ be drawn off with a convenient fire, the corroded Mercury will remain in the bottom, in the form of a substance that may be made to appear of differing Colours by differing degrees of Heat; As I remember that lately having purposely abstracted _Aqua fortis_ from some Quicksilver that we had dissolv'd in it, so that there remain'd a white _Calx_, exposing that to several degrees of Fire, and afterwards to a naked one, we obtain'd some new Colours, and at length the greatest part of the _Calx_ lying at the Bottome of the Vial, and being brought partly to a Deep Yellow, and partly to a Red Colour, the rest appear'd elevated to the upper part and neck of the Vial, some in the form of a Reddish, and some of an Ash-Colour Sublimate. But of the differing Colours which by differing wayes and working of Quick Silver with Fire, and Saline Bodies, may be produc'd in Precipitates, I may elsewhere have occasion to take further notice. I also told you not long since, that if you corrode Quick-silver with Oyl of Vitriol instead of _Aqua-fortis_, and abstract the _Menstruum_, there will remain a White _Calx_ which by the Affusion of Fair Water presently turns into a Lemmon Colour. And ev'n the _Succedaneum_ to a _Menstruum_ may sometimes serve the turn to change the Colours of a Metal. The lovely Red which Painters call Vermillion, is made of Mercury, which is of the Colour of Silver, and of Brimstone which is of Kin to that of Gold, Sublim'd up together in a certain proportion, as is vulgarly known to Spagyrists.

_EXPERIMENT XLVIII._

The third chief sort of the Advent.i.tious Colours of Metals, is, that which is produc'd by a.s.sociating them (especially when Calcin'd) with other fusible Bodies, and Princ.i.p.ally Venice, and other fine Gla.s.s devoid of Colour.

I have formerly given you an Example, whereby it may appear, that a Metal may impart to Gla.s.s a Colour much differing from its own, when I told you, how with Silver, I had given Gla.s.s a lovely Golden Colour. And I shall now add, that I have Learn'd from one of the Chief Artificers that sells Painted Gla.s.s, that those of his Trade Colour it Yellow with a preparation of the _Calx_ of Silver. Though having lately had occasion among other Tryals to mingle a few grains of Sh.e.l.l-silver (such as is imploy'd with the Pensil and Pen) with a convenient proportion of powder'd Crystal Gla.s.s, having kept them two or three hours in fusion, I was surpriz'd to find the Colliquated Ma.s.s to appear upon breaking the Crucible of a lovely Saphirine Blew, which made me suspect my Servant might have brought me a wrong Crucible, but he constantly affirm'd it to be the same wherein the Silver was put, and considerable Circ.u.mstances countenanc'd his a.s.sertion, so that till I have opportunity to make farther Tryal, I cannot but suspect, either that Silver which is not (which is not very probable) brought to a perfect Fusion and Colliquation with Gla.s.s, may impart to it other Colours than when Neal'd upon it, or else (which is less unlikely) that though Silver Beaters usually chuse the finest Coyn they can get, as that which is most extensive under the Hammer, yet the Silver-leaves of which this Shel-silver was made, might retain so much Copper as to enable it to give the predominant tincture to the Gla.s.s.

For, I must proceed to tell you (_Pyrophilus_) as another instance of the Advent.i.tious Colours of Metals, that which is something strange, Namely, That though Copper Calcin'd _per se_ affords but a Dark and basely Colour'd _Calx_, yet the Gla.s.smen do with it, as themselves inform me, Tinge their Gla.s.s green. And I remember, that when once we took some crude Copper, and by frequent Ignition quenching it in Water had reduc'd it to a Dark and Ill-colour'd Powder, and afterward kept it in Fusion in about a 100. times its weight of fine Gla.s.s, we had, though not a Green, yet a Blew colour'd Ma.s.s, which would perhaps have been Green, if we had hit right upon the Proportion of the Materials, and the Degree of Fire, and the Time wherein it ought to be kept in Fusion, so plentifully does that Metal abound in a Venerial Tincture, as Artists call it, and in so many wayes does it disclose that Richness. But though Copper do as we have said give somewhat near the like Colour to Gla.s.s, which it does to _Aqua-fortis_, yet it seems worth inquiry, whether those new Colours which Mineral Bodies disclose in melted Gla.s.s, proceed from the Coalition of the Corpuscles of the Mineral with the Particles of the Gla.s.s as such, or from the Action (excited or actuated by fire) of the Alcalizate Salt (which is a main Ingredient of Gla.s.s,) upon the Mineral Body, or from the concurrence of both these Causes, or else from any other. But to return to that which we were saying, we may observe that _Putty_ made by calcining together a proportion of Tin and Lead, as it is it self a White _Calx_, so does it turn the _Pitta di Crystallo_ (as the Gla.s.smen call the matter of the Purer sort of Gla.s.s, wherewith it is Colliquated into a White Ma.s.s, which if it be opacous enough is employ'd, as we elsewhere declare, for White Amel. But of the Colours which the other Metals may be made to produce in Colourless Gla.s.s, and other Vitrifiable Bodies, that have native Colours of their own, I must leave you to inform your self upon Tryal, or at least must forbear to do it till another time, considering how many Annotations are to follow, upon what has in this and the two former Experiments been said already.

_Annotation I._

When the Materials of Gla.s.s being melted with Calcin'd Tin, have compos'd a Ma.s.s Undiaphanous and White, this White Amel is as it were the Basis of all those fine Concretes that Goldsmiths and several Artificers imploy in the curious Art of Enamelling. For this White and Fusible substance will receive into it self, without spoyling them, the Colours of divers other Mineral substances, which like it will indure the fire.

_Annotation II._

So that as by the present (XLVIII.) Experiment it appears, that divers Minerals will impart to fusible Ma.s.ses, Colours differing from their own; so by the making and compounding of Amels, it may appear, that divers Bodies will both retain their Colour in the fire, and impart the _same_ to some others wherewith they were vitrifi'd, and in such Tryals as that mention'd in the 17. Experiment, where I told you, that ev'n in Amels a Blew and Yellow will compound a Green. 'Tis pretty to behold, not only that some Colours are of so fix'd a Nature, as to be capable of mixture without receiving any detriment by the fire, that do's so easily destroy or spoyl those of other Bodies; but Mineral Pigments may be mingled by fire little less regularly and successfully, than in ordinary Dyeing Fatts, the vulgar Colours are wont to be mingled by the help of Water.

_Annotation III._

'Tis not only Metalline, but other Mineral Bodies, that may be imploy'd, to give Tinctures unto Gla.s.s (and 'tis worth noting how small a quant.i.ty of some Mineral substances, will Tinge a Comparatively vast proportion of Gla.s.s, and we have sometimes attempted to Colour Gla.s.s, ev'n with Pretious Stones, and had cause to think the Experiment not cast away. And 'tis known by them that have look'd into the Art of Gla.s.s, that the Artificers use to tinge their Gla.s.s Blew, with that Dark Mineral _Zaffora_, (some of my Tryals on which I elsewhere acquaint you) which some would have to be a Mineral Earth, others a Stone, and others neither the one, nor the other, but which is confessedly of a Dark, but not a Blew Colour, though it be not agreed of what particular Colour it is. 'Tis likewise though a familiar yet a remarkable practise among those that Deal in the making of Gla.s.s, to imploy (as some of themselves have inform'd me) what they call Manganess, and some Authors call _Magnesia_ (of which I make particular mention in another Treatise) to exhibit in Gla.s.s not only other Colours than its own, (which is so like in Darkness or blackishness to the Load stone, that 'tis given by Mineralists, for one of the Reasons of its Latine Name) but Colours differing from one another. For though they use it, (which is somewhat strange) to Clarifye their Gla.s.s, and free it from that Blewish Greenish Colour, which else it would too often be subject to, yet they also imploy it in certain proportions, to tinge their Gla.s.s both with a Red colour, and with a Purplish or Murry, and putting in a greater Quant.i.ty, they also make with it that deep obscure Gla.s.s which is wont to pa.s.s for Black, which agrees very well with, and may serve to confirm what we noted near the beginning of the 44th Experiment, of the seeming Blackness of those Bodies that are overcharg'd with the Corpuscles of such Colours, as Red, or Blew, or Green, &c. And as by several Metals and other Minerals we can give various Colours to Gla.s.s, so on the other side, by the differing Colours that Mineral Oars, or other Mineral Powders being melted with Gla.s.s disclose in it, a good Conjecture may be oftentimes made of the Metall or known Mineral, that the Oar propos'd, either holds, or is most of kin to.

And this easie way of examining Oars, may be in some cases of good use, and is not ill deliver'd by _Glauber_, to whom I shall at present refer you, for a more particular account of it: unless your Curiosity command also what I have observ'd about these matters; only I must here advertise you, that great circ.u.mspection is requisite to keep this way from proving fallacious, upon the account of the variations of Colour that may be produc'd by the differing proportions that may be us'd betwixt the Oar and the Gla.s.s, by the Richness or Poorness of the Oar it self, by the Degree of Fire, and (especially) by the Length of Time, during which the matter is kept in fusion; as you will easily gather from what you will quickly meet with in the following Annotation upon this present 48th Experiment.

_Annotation IV._

There is another way and differing enough from those already mention'd, by which Metalls may be brought to exhibit advent.i.tious Colours: For by This, the Metall do's not so much impart a Colour to another Body, as receive a Colour from it, or rather both Bodies do by the new Texture resulting from their mistion produce a new Colour. I will not insist to this purpose upon the Examples afforded us by yellow Orpiment, and common Sea Salt, from which, sublim'd together, Chymists unanimously affirm their White or Crystalline a.r.s.enick to be made: But 'tis not unworthy our noting, That though Yellow Orpiment be acknowledg'd to be the Copiousest by far of the two Ingredients of a.r.s.enick, yet this last nam'd Body being duely added to the highest Colour'd Metall Copper, when 'tis in fusion, gives it a whiteness both within and without. Thus _Lapis Calaminaris_ changes and improves the Colour of Copper by turning it into Bra.s.s. And I have sometimes by the help of Zinck duely mix'd after a certain manner, given Copper one of the Richest Golden Colours that ever I have seen the Best true Gold Enn.o.bled with. But pray have a care that such Hints fall not into any hands that may mis-imploy them.

_Annotation V._

Upon the Knowledge of the differing wayes of making Minerals and Metalls produce their advent.i.tious Colours in Bodies capable of Vitrification, depends the pretty Art of making what Chymists by a Barbarous Word are pleas'd to call _Amanses_, that is counterfeit, or fact.i.tious Gemms, as Emeralds, Rubies, Saphires, Topazes, and the like. For in the making of these, though pure Sand or Calcin'd Crystal give the Body, yet 'tis for the most part some Metalline or Mineral _Calx_, mingled in a small proportion that gives the Colour. But though I have many years since taken delight, to divert my self with this pleasing Art, and have seen very pretty Productions of it, yet besides that I fear I have now forgot most of the little Skill I had in it, this is no place to entertain you with what would rather take up an intire Discourse, than be comprehended in an Annotation; wherefore the few things which I shall here take notice of to you, are only what belong to the present Argument, Namely,

First, That I have often observ'd that Calcin'd Lead Colliquated with fine White Sand or Crystal, reduc'd by ignitions and subsequent extinctions in Water to a subtile Powder, will of it self be brought by a due Decoction to give a cleer Ma.s.s Colour'd like a _German_ Amethyst. For though this gla.s.s of Lead, is look'd upon by them that know no better way of making _Amanses_, as the grand Work of them all, yet which is an inconvenience that much blemishes this way, the Calcin'd Lead it self does not only afford matter to the _Amanses_, but has also as well as other Metals a Colour of its own, which as I was saying, I have often found to be like that of _German_ (as many call them) not Eastern Amethysts.

Secondly, That nevertheless this Colour may be easily over-powr'd by those of divers other Mineral Pigments (if I may so call them) so that with a gla.s.s of Lead, you may Emulate (for Instance) the fresh and lovely Greenness of an Emerald, though in divers cases the Colour which the Lead it self upon Vitrification tends to, may vitiate that of the Pigment, which you would introduce into the Ma.s.s.