Micrographia Part 7

But insteed of meeting with what I look'd for, I met with somewhat more admirable; and that was, that I found my self utterly unable to see through them when placed both together, though they were transparent enough when asunder; and though I could see through twice the thickness, when both of them were fill'd with the same colour'd liquors, whether both with the Yellow, or both with the Blue, yet when one was fill'd with the Yellow, the other with the Blue, and both looked through, they both appear'd dark, onely when the parts near the tops were look'd through, they exhibited Greens, and those of very great variety, as I expected, but the Purples and other colours, I could not by any means make, whether I endeavour'd to look through them both against the Sun, or whether I plac'd them against the hole of a darkned room.

But notwithstanding this mis-ghessing, I proceeded on with my trial in a dark room, and having two holes near one another, I was able, by placing my Wedges against them, to mix the ting'd Rays that past through them, and fell on a sheet of white Paper held at a convenient distance from them as I pleas'd; so that I could make the Paper appear of what colour I would, by varying the thicknesses of the Wedges, and consequently the tincture of the Rays that past through the two holes, and sometimes also by varying the Paper, that is, insteed of a white Paper, holding a gray, or a black piece of Paper.

Whence I experimentally found what I had before imagin'd, that all the varieties of colours imaginable are produc'd from several degrees of these two colours, namely, Yellow and Blue, or the mixture of them with light and darkness, that is, white and black. And all those almost infinite varieties which Limners and Painters are able to make by compounding those several colours they lay on their Shels or _Palads_, are nothing else, but some _compositum_, made up of some one or more, or all of these four.

Now, whereas it may here again be objected, that neither can the Reds be made out of the Yellows, added together, or laid on in greater or less quant.i.ty, nor can the Yellows be made out of the Reds though laid never so thin; and as for the addition of White or Black, they do nothing but either whiten or darken the colours to which they are added, and not at all make them of any other kind of colour: as for instance, _Vermilion_, by being temper'd with White Lead, does not at all grow more Yellow, but onely there is made a whiter kind of Red. Nor does Yellow _Oker_, though laid never so thick, produce the colour of _Vermilion_, nor though it be temper'd with Black, does it at all make a Red; nay, though it be temper'd with White, it will not afford a fainter kind of Yellow, such as _masticut_, but onely a whiten'd Yellow; nor will the Blues be _diluted_ or deepned after the manner I speak of, as _Indico_ will never afford so fine a Blue as _Ultramarine_ or _Bise_; nor will it, temper'd with _Vermilion_, ever afford a Green, though each of them be never so much temper'd with white.

To which I answer, that there is a great difference between _diluting_ a colour and whitening of it; for _diluting_ a colour, is to make the colour'd parts more thin, so that the ting'd light, which is made by trajecting those ting'd bodies, does not receive so deep a tincture; but whitening a colour is onely an intermixing of many clear reflections of light among the same ting'd parts; deepning also, and darkning or blacking a colour, are very different; for deepning a colour, is to make the light pa.s.s through a greater quant.i.ty of the same tinging body; and darkning or blacking a colour, is onely interposing a mult.i.tude of dark or black spots among the same ting'd parts, or placing the colour in a more faint light.

First therefore, as to the former of these operations, that is, diluting and deepning, most of the colours us'd by the Limners and Painters are incapable of, to wit, _Vermilion_ and _Red-lead_, and _Oker_, because the ting'd parts are so exceeding small, that the most curious Grindstones we have, are not able to separate them into parts actually divided so small as the ting'd particles are; for looking on the most curiously ground _Vermilion_, and _Oker_, and _Red-lead_, I could perceive that even those small _corpuscles_ of the bodies they left were compounded of many pieces, that is, they seem'd to be small pieces compounded of a mult.i.tude of lesser ting'd parts: each piece seeming almost like a piece of Red Gla.s.s, or ting'd Crystal all flaw'd; so that unless the Grindstone could actually divide them into smaller pieces then those flaw'd particles were, which compounded that ting'd mote I could see with my _Microscope_, it would be impossible to _dilute_ the colour by grinding, which, because the finest we have will not reach to do in _Vermilion_ or _Oker_, therefore they cannot at all, or very hardly be _diluted_.

Other colours indeed, whose ting'd particles are such as may be made smaller, by grinding their colour, may be _diluted_. Thus several of the Blues may be _diluted_, as _Smalt_ and _Bise_; and _Masticut_, which is Yellow, may be made more faint: And even _Vermilion_ it self may, by too much grinding, be brought to the colour of _Red-lead_, which is but an Orange colour, which is confest by all to be very much upon the Yellow.

Now, though perhaps somewhat of this _diluting_ of _Vermilion_ by overmuch grinding may be attributed to the Grindstone, or muller, for that some of their parts may be worn off and mixt with the colour, yet there seems not very much, for I have done it on a Serpentine-stone with a muller made of a Pebble, and yet observ'd the same effect follow.

And secondly, as to the other of these operations on colours, that is, the deepning of them, Limners and Painters colours are for the most part also uncapable. For they being for the most part _opacous_; and that _opacousness_, as I said before, proceeding from the particles, being very much flaw'd, unless we were able to joyn and re-unite those flaw'd particles again into one piece, we shall not be able to deepen the colour, which since we are unable to do with most of the colours which are by Painters accounted _opacous_, we are therefore unable to deepen them by adding more of the same kind.

But because all those _opacous_ colours have two kinds of beams or Rays reflected from them, that is, Rays unting'd, which are onely reflected from the outward surface, without at all penetrating of the body, and ting'd Rays which are reflected from the inward surfaces or flaws after they have suffer'd a two-fold refraction; and because that transparent liquors mixt with such _corpuscles_, do, for the most part, take off the former kind of reflection; therefore these colours mixt with Water or Oyl, appear much deeper than when dry, for most part of that white reflection from the outward surface is remov'd. Nay, some of these colours are very much deepned by the mixture with some transparent liquor, and that because they may perhaps get between those two flaws, and so consequently joyn two or more of those flaw'd pieces together; but this happens but in a very few.

Now, to shew that all this is not _gratis dictum_, I shall set down some Experiments which do manifest these things to be probable and likely, which I have here deliver'd.

For, first, if you take any ting'd liquor whatsoever, especially if it be pretty deeply ting'd, and by any means work it into a froth, the _congeries_ of that froth shall seem an _opacous_ body, and appear of the same colour, but much whiter than that of the liquor out of which it is made. For the abundance of reflections of the Rays against those surfaces of the bubbles of which the froth consists, does so often rebound the Rays backwards, that little or no light can pa.s.s through, and consequently the froth appears _opacous_.

Again, if to any of these ting'd liquors that will endure the boiling there be added a small quant.i.ty of fine flower (the parts of which through the _Microscope_ are plainly enough to be perceiv'd to consist of transparent _corpuscles_) and suffer'd to boyl till it thicken the liquor, the ma.s.s of the liquor will appear _opacous_, and ting'd with the same colour, but very much whiten'd.

Thus, if you take a piece of transparent Gla.s.s that is well colour'd, and by heating it, and then quenching it in Water, you flaw it all over, it will become _opacous_, and will exhibit the same colour with which the piece is ting'd, but fainter and whiter.

Or, if you take a Pipe of this transparent Gla.s.s, and in the flame of a Lamp melt it, and then blow it into very thin bubbles, then break those bubbles, and collect a good parcel of those _laminae_ together in a Paper, you shall find that a small thickness of those Plates will const.i.tute an _opacous_ body, and that you may see through the ma.s.s of Gla.s.s before it be thus _laminated_, above four times the thickness: And besides, they will now afford a colour by reflection as other _opacous_ (as they are call'd) colours will, but much fainter and whiter than that of the Lump or Pipe out of which they were made.

Thus also, if you take _Putty_, and melt it with any transparent colour'd Gla.s.s, it will make it become an _opacous_ colour'd lump, and to yield a paler and whiter colour than the lump by reflection.

The same thing may be done by a preparation of _Antimony_, as has been shewn by the Learned _Physician_, Dr. _C.M._ in his Excellent Observations and Notes on _Nery's Art of Gla.s.s_; and by this means all transparent colours become _opacous_, or _ammels_. And though by being ground they lose very much of their colour, growing much whiter by reason of the mult.i.tude of single reflections from their outward surface, as I shew'd afore, yet the fire that in the nealing or melting re-unites them, and so renews those _spurious_ reflections, removes also those whitenings of the colour that proceed from them.

As for the other colours which Painters use, which are transparent, and us'd to varnish over all other paintings, 'tis well enough known that the laying on of them thinner or thicker, does very much _dilute_ or deepen their colour.

Painters Colours therefore consisting most of them of solid particles, so small that they cannot be either re-united into thicker particles by any Art yet known, and consequently cannot be deepned; or divided into particles so small as the flaw'd particles that exhibit that colour, much less into smaller, and consequently cannot be _diluted_; It is necessary that they which are to imitate all kinds of colours, should have as many degrees of each colour as can be procur'd.

And to this purpose, both Limners and Painters have a very great variety both of Yellows and Blues, besides several other colour'd bodies that exhibit very compounded colours, such as Greens and Purples; and others that are compounded of several degrees of Yellow, or several degrees of Blue, sometimes unmixt, and sometimes compounded with several other colour'd bodies.

The Yellows, from the palest to the deepest Red or Scarlet, which has no intermixture of Blue, are _pale and deep Masticut, Orpament, English Oker, brown Oker, Red Lead, and Vermilion, burnt English Oker, and burnt brown Oker,_ which last have a mixture of dark or dirty parts with them, &c.

Their Blues are several kinds of _Smalts_, and _Verditures_, and _Bise_, and _Ultramarine_, and _Indico_, which last has many dirty or dark parts intermixt with it.

Their compounded colour'd bodies, as _Pink_, and _Verdigrese_, which are Greens, the one a _Popingay_, the other a _Sea-green_; then _Lac_, which is a very lovely _Purple_.

To which may be added their Black and White, which they also usually call Colours, of each of which they have several kinds, such as _Bone Black_, made of _Ivory_ burnt in a close Vessel, and _Blue Black_, made of the small coal of _Willow_, or some other Wood; and _Cullens earth_, which is a kind of brown Black, &c. Their usual Whites are either artificial or natural _White Lead_, the last of which is the best they yet have, and with the mixing and tempering these colours together, are they able to make an imitation of any colour whatsoever: Their Reds or deep Yellows, they can _dilute_ by mixing pale Yellows with them, and deepen their pale by mixing deeper with them; for it is not with _Opacous_ colours as it is with transparent, where by adding more Yellow to yellow, it is deepned, but in _opacous_ _diluted_. They can whiten any colour by mixing White with it, and darken any colour by mixing Black, or some dark and dirty colour. And in a word, most of the colours, or colour'd bodies they use in Limning and Painting, are such, as though mixt with any other of their colours, they preserve their own hue, and by being in such very smal parts dispers'd through the other colour'd bodies, they both, or altogether represent to the eye a _compositum_ of all; the eye being unable, by reason of their smalness, to distinguish the peculiarly colour'd particles, but receives them as one intire _compositum_: whereas in many of these, the _Microscope_ very easily distinguishes each of the compounding colours distinct, and exhibiting its own colour.

Thus have I by gently mixing _Vermilion_ and _Bise_ dry, produc'd a very fine Purple, or mixt colour, but looking on it with the _Microscope_, I could easily distinguish both the Red and the Blue particles, which did not at all produce the _Phantasm_ of Purple.

To summ up all therefore in a word, I have not yet found any solid colour'd body, that I have yet examin'd, perfectly _opacous_; but those that are least transparent are _Metalline_ and _Mineral_ bodies, whose particles generally, seeming either to be very small, or very much flaw'd, appear for the most part _opacous_, though there are very few of them that I have look'd on with a _Microscope_, that have not very plainly or circ.u.mstantially manifested themselves transparent.

And indeed, there seem to be so few bodies in the world that are _in minimis_ opacous, that I think one may make it a rational _Query_, Whether there be any body absolutely thus _opacous_? For I doubt not at all (and I have taken notice of very many circ.u.mstances that make me of this mind) that could we very much improve the _Microscope_, we might be able to see all those bodies very plainly transparent, which we now are fain onely to ghess at by circ.u.mstances. Nay, the Object Gla.s.ses we yet make use of are such, that they make many transparent bodies to the eye, seem _opacous_ through them, which if we widen the Aperture a little, and cast more light on the objects, and not charge the Gla.s.ses so deep, will again disclose their transparency.

Now, as for all kinds of colours that are dissolvable in Water, or other liquors, there is nothing so manifest, as that all those ting'd liquors are transparent; and many of them are capable of being _diluted_ and compounded or mixt with other colours, and divers of them are capable of being very much chang'd and heightned, and fixt with several kinds of _Saline menstruums_. Others of them upon compounding, destroy or vitiate each others colours, and _precipitate_, or otherwise very much alter each others tincture. In the true ordering and _diluting_, and deepning, and mixing, and fixing of each of which, consists one of the greatest mysteries of the Dyers; of which particulars, because our _Microscope_ affords us very little information, I shall add nothing more at present; but onely that with a very few tinctures order'd and mixt after certain ways, too long to be here set down, I have been able to make an appearance of all the various colours imaginable, without at all using the help of _Salts_, or _Saline menstruums_ to vary them.

As for the mutation of Colours by _Saline menstruums_, they have already been so fully and excellently handled by the lately mention'd Incomparable _Authour_, that I can add nothing, but that of a mult.i.tude of trials that I made, I have found them exactly to agree with his Rules and Theories; and though there may be infinite instances, yet may they be reduc'd under a few Heads, and compris'd within a very few Rules. And generally I find, that _Saline menstruums_ are most operative upon those colours that are Purple, or have some degree of Purple in them, and upon the other colours much less. The _spurious_ pulses that compose which, being (as I formerly noted) so very neer the middle between the true ones, that a small variation throws them both to one side, or both to the other, and so consequently must make a vast mutation in the formerly appearing Colour.

Observ. XI. _Of _Figures_ observ'd in small Sand._

Sand generally seems to be nothing else but exceeding small Pebbles, or at least some very small parcels of a bigger stone; the whiter kind seems through the _Microscope_ to consist of small transparent pieces of some _pellucid_ body, each of them looking much like a piece of _Alum_, or _Salt Gem_; and this kind of Sand is angled for the most part irregularly, without any certain shape, and the _granules_ of it are for the most part flaw'd, through amongst many of them it is not difficult to find some that are perfectly _pellucid_, like a piece of clear Crystal, and divers likewise most curiously shap'd, much after the manner of the bigger _Stiriae_ of Crystal, or like the small Diamants I observ'd in certain Flints, of which I shall by and by relate; which last particular seems to argue, that this kind of Sand is not made by the comminution of greater transparent Crystaline bodies, but by the _concretion_ or _coagulation_ of Water, or some other fluid body.

There are other kinds of courser Sands, which are browner, and have their particles much bigger; these, view'd with a _Microscope_, seem much courser and more _opacous_ substances, and most of them are of some irregularly rounded Figures; and though they seem not so _opacous_ as to the naked eye, yet they seem very foul and cloudy, but neither do these want curiously transparent, no more than they do regularly figur'd and well colour'd particles, as I have often found.

There are mult.i.tudes of other kinds of Sands, which in many particulars, plainly enough discoverable by the _Microscope_, differ both from these last mention'd kinds of Sands, and from one another: there seeming to be as great variety of Sands, as there is of Stones. And as amongst Stones some are call'd precious from their excellency, so also are there Sands which deserve the same Epithite for their beauty; for viewing a small parcel of _East-India_ Sand (which was given me by my highly honoured friend, Mr.

_Daniel Colwall_) and, since that, another parcel, much of the same kind, I found several of them, both very transparent like precious Stones, and regularly figur'd like Crystal, _Cornish_ Diamants, some Rubies, &c. and also ting'd with very lively and deep colours, like _Rubys_, _Saphyrs_, _Emeralds_, &c. These kinds of granuls I have often found also in _English_ Sand. And 'tis easie to make such a counterfeit Sand with deeply ting'd Gla.s.s, Enamels and Painters colours.

It were endless to describe the mult.i.tudes of Figures I have met with in these kind of minute bodies, such as _Spherical_, _Oval_, _Pyramidal_, _Conical_, _Prismatical_, of each of which kinds I have taken notice.

But amongst many others, I met with none more observable than this pretty Sh.e.l.l (described in the _Figure_ X. of the fifth _Scheme_) which, though as it was light on by chance, deserv'd to have been omitted (I being unable to direct any one to find the like) yet for its rarity was it not inconsiderable, especially upon the account of the information it may afford us. For by it we have a very good instance of the curiosity of Nature in another kind of Animals which are remov'd, by reason of their minuteness, beyond the reach of our eyes, so that as there are several sorts of Insects, as Mites, and others, so small as not yet to have had any names; (some of which I shall afterwards describe) and small Fishes, as Leeches in Vineger; and smal vegetables, as Moss, and Rose-Leave-plants; and small Mushroms, as mould: so are there, it seems, small Shel-fish likewise, Nature shewing her curiosity in every Tribe of _Animals_, _Vegetables_, and _Minerals_.

I was trying several small and single Magnifying Gla.s.ses, and casually viewing a parcel of white Sand, when I perceiv'd one of the grains exactly shap'd and wreath'd like a Sh.e.l.l, but endeavouring to distinguish it with my naked eye, it was so very small, that I was fain again to make use of the Gla.s.s to find it; then, whilest I thus look'd on it, with a Pin I separated all the rest of the granules of Sand, and found it afterwards to appear to the naked eye an exceeding small white spot, no bigger than the point of a Pin. Afterwards I view'd it every way with a better _Microscope_ and found it on both sides, and edge-ways, to resemble the Sh.e.l.l of a small Water-Snail with a flat spiral Sh.e.l.l: it had twelve wreathings, a, b, c, d, e, &c. all very proportionably growing one less than another toward the middle or center of the Sh.e.l.l, where there was a very small round white spot. I could not certainly discover whether the Sh.e.l.l were hollow or not, but it seem'd fill'd with somewhat, and 'tis probable that it might be _petrify'd_ as other larger Shels often are, such as are mention'd in the seventeenth _Observation_.

Observ. XII. _Of _Gravel_ in Urine._

I Have often observ'd the Sand or Gravel of Urine, which seems to be a _tartareous_ substance, generated out of a _saline_ and a _terrestrial_ substance _crystalliz'd_ together, in the form of _Tartar_, sometimes sticking to the sides of the _Urinal_, but for the most part sinking to the bottom, and there lying in the form of coorse common Sand; these, through the _Microscope_, appear to be a company of small bodies, partly transparent and partly _opacous_, some White, some Yellow, some Red, others of more brown and duskie colours.

The Figure of them is for the most part flat, in the manner of Slats or such like plated Stones, that is, each of them seem to be made up of several other thinner Plates, much like _Muscovie Gla.s.s_, or _Englsh Sparr_ to the last of which, the white plated Gravel seems most likely; for they seem not onely plated like that, but their sides shap'd also into _Rhombs_, _Rhomboeids_, and sometimes into _Rectangles_ and _Squares_. Their bigness and Figure may be seen in the second _Figure_ of the seventh _Plate_, which represents about a dozen of them lying upon a plate ABCD, some of which, as a, b, c, d seem'd more regular than the rest, and e, which was a small one, sticking on the top of another, was a perfet _Rhomboeid_ on the top, and had four _Rectangular_ sides.

The line E which was the the measure of the _Microscope_, is 1/32 part of an _English_ Inch, so that the greatest bredth of any of them, exceeded not 1/128 part of an Inch.

Putting these into several liquors, I found _oyl of Vitriol_, _Spirit of Urine_, and several other _Saline menstruums_ to dissolve them; and the first of these in less than a minute without _Ebullition_, Water, and several other liquors, had no sudden operation upon them. This I mention, because those liquors that dissolve them, first make them very white, not _vitiating_, but rather rectifying their Figure, and thereby make them afford a very pretty object for the _Microscope_.

How great an advantage it would be to such as are troubled with the Stone, to find some _menstruum_ might dissolve them without hurting the Bladder, is easily imagin'd, since some _injections_ made of such bodies might likewise dissolve the stone, which seems much of the same nature.

It may therefore, perhaps, be worthy some Physicians enquiry, whether there may not be something mixt with the Urine in which the Gravel or Stone lies, which may again make it dissolve it, the first of which seems by it's regular Figures to have been sometimes _Crystalliz'd_ out of it. For whether this _Crystallization_ be made in the manner as _Alum_, _Peter_, &c. are _crystallized_ out of a cooling liquor, in which, by boyling they have been dissolv'd; or whether it be made in the manner of _Tartarum Vitriolatum_, that is, by the _Coalition_ of an _acid_ and a _Sulphureous_ substance, it seems not impossible, but that the liquor it lies in, may be again made a _dissolvent_ of it. But leaving these inquiries to Physicians or Chymists, to whom it does more properly belong, I shall proceed.

Observ. XIII. _Of the small _Diamants_, or _Sparks_ in _Flints_._

Chancing to break a Flint stone in pieces, I found within it a certain cavity all crusted over with a very pretty candied substance, some of the parts of which, upon changing the posture of the Stone, in respect of the _Incident_ light, exhibited a number of small, but very vivid reflections; and having made use of my _Microscope_, I could perceive the whole surface of that cavity to be all beset with a mult.i.tude of little _Crystaline_ or _Adamantine_ bodies, so curiously shap'd, that it afforded a not unpleasing object.

Having considered those vivid _repercussions_ of light, I found them to be made partly from the plain external surface of these regularly figured bodies (which afforded the vivid reflexions) and partly to be made from within the somewhat _pellucid_ body, that is, from some surface of the body, opposite to that superficies of it which was next the eye.