The art of glass shewing how to make all sorts of glass, crystal and enamel : likewise the making of pearls, precious stones, china and looking-glasses : to which is added, the method of painting on glass and enameling : also how to extract the colours from minerals, metals, herbs and flowers ... : illustrated with proper sculptures / written originally in French, by Mr. H. Blancourt, and now first translated into English ; with an appendix, containing exact instructions for making glass-eyes of all colours.

OF THE ART OF GLASS. (Book 11)

BOOK XI. Wherein the Manner of imitating all sorts of Pearl is shewn, and done so effectually, as to give them an equal Splendour and Beauty with those which are Naturally produced in the Sea. (Book 11)

CHAP. CCXLII.

ALL the Ancients who have treated of the se∣veral Sorts, and Properties of Precious Stones, have at the same time discoursed of Pearls, because they claim a place among the first and best of Jewels, in respect of their Value, as well as their Beauty, and the fixt Quality which they contain, they having been at all times sought

after, for the Ornament and Pleasure of Ladies, as they are at this Day; for these Reasons we thought it convenient to give them a Place among our Works, that (from our Experience) the Curious might be informed how to make such Ar••ificially as fine and splendid, as those which Nature forms in the Depth of the Ocean.

We avow that the Production of Pearls, is very different from that of Precious-Stones, because the latter proceeds from the Earth, and the former quite contrary, from the Shell-Creatures which are shrouded in the Bottom of the Sea; these receive their Nourishment from the same Liquld Substance which crntributes to the Growth of the Shells, and this Slimy Substance is resolved from the Watry Hu∣mour of the Creature, by three several Processes. The first dries it by degrees, the next brings it to an hardness, and last of all, 'tis at certain times em∣plyed by the Animal, for the Increase of its Shell, and the place where this is effected in the inmost in∣veloped recesses thereof. Now the first Principle of these, and all other Precious Stones, descends from Above, to wit, the Universal Seed, which alone can give Birth and Increase to all the Tenants of this vast Universe; and these Precious Stones, as well as the Metals, are nourished in the Womb of the Earth, so the living Creatures bear each other the Foetus within its Parent, &c.

The Oriental Pearls are generated in the Fish, which contains them with the Mother as the Occiden∣tal, or Western in our Oysters, but the Beauty of these two, is very different, the Oriental being of a Silver White, and exceeding splendid to the Occi∣dental; the best of these latter seldom arriving to any higher than the Colour of Milk. We will not here take notice of the particular Places of the East, where they are found, but only inform you, That

the best and most beautiful▪ come from the Persian∣Gulf, about the Isle of Ormus Bassora: They are found in Europe, not only in the Sea, but in Rivers, and Fresh Water; we have them from Scotland, Si∣lesia, Bohemia, Frisia, Lorrain, &c. in all which Pla∣ces they are found very fine, only those of Frisia, are very small.

'Tis thought the Fish wherein the Pearl is genera∣ted, becoming Sickly and Weak, and not able to di∣spose of the Slimy Moisture for the Growth of its Shell, it remains in the Body thereof, and is dried: Hence the Birth of the Pearl, and so by a continual supply of the like Substance still coating it a-new, it becomes large, just as the Stone in the Bladder of Man, and other Creatures, engenders, and is fed by a Clammy Humour, which cannot be emitted by Urine, but remains behind, and so hardens and be∣comes a Stone: After the like manner the Bezoar Stone is bred in the Indian Goats of the Kingdom of Golcondea, and in the Galls of Wild-Boars in India, and the Hedgehogs of Malacca; so several other Stones, to which they give the Name of Bezoar, are found in the Galls of Beeves, Deer, Goats, and o∣ther Animals in France, and elsewhere, all which have great Vertues in Physick.

How great and effectual those Pearls are in Physi∣cal Matters, and what Successes they reach there, is not to our Purpose; we only intend to shew the way of imitating their Beauty by Art so finely, and with such exactness of Lustre, as not to leave it in the power of any to distinguish them easily from the true and Natural ones, they being made of the very fi∣nest sort of Paste that can be, and the same Stuff as the true ones.

Poverty and Pride are two inseparable Compani∣ons among our French; such Ladies as make use of pure Pearl, are those that can afford it, and the lit∣tle

Creatures that cannot reach the Price, but would however appear gay, are obliged to have recourse to the Counterfeit, and content themselves with I∣mitation only of Nature: 'Tis some Years since the Use of these latter was introduced in France, which now, not only the Puny Ladies, but those of Birth and Quality do wear; this proceeded all from that Fashion which insensibly reached still at the larger Pearls, which these Ladies coveted for Ornament; and because they could not be furnished enough with true, they made use of the Artificial; whence the Common Sort of Persons receiv'd the Advantage to vie with Persons of the First Rank and Quality; which they don't fail to do, without Consideration of either Estate, or Condition, but only to conform with the Mode.

The Counterfeit Pearls, which are usually made, are just the Colour of the Pastes, and of no Conti∣nuance but for the present; they are done with a Composition of Brittle Glass and Wax a little melt∣ed; and for Colouring, they use prepared Mercury, Mouth-Glue, or any other Drug, to give them a Brightness, which soon Peels off, and Scales away, especially in the Heat of Summer: The Way which we will give, is not only very good and solid, but exceeding fine, being effected with Seed Pearl; we grant these Pastes to be much dearer than the for∣mer, but consider their Fineness, and that they'll last for ever; we shall also shew how to make the Counterfeits finer and harder; and we are persuad∣ed, that the Preparation of those we shall assign, will appear so easie, and yet produce such fine Imi∣tations, as shall be very satisfactory.

CHAP. CCXLIII. To imitate fine Oriental Pearl.

THE Difference between those which are at pre∣sent wore by the Ladies, and such as we shall prescribe, as to the Goodness, Hardness, and Fine∣ness of the Stuff, we have already endeavoured to clear.

But before we proceed any further, take these re∣maining Parts of the Furnace in Chap. 52.

The Letter O, is the Balneum Mariae.

P, The Vessel for containing the Sand, or Ash∣Fire.

Q, The Eyes, or Holes of the Furnace.

R, Their Cover, which when they are set on, draw in the Air, and increase the Heat for Fusion; the others are Crucibles.

We did also intend to give the Description of a∣nother Furnace at the close of the Fifth Book, as well for the Service of the Matters in that, as the Sixth Book: You may, however take it along with you here.

A, is the Ash-hole; you may add to it an Hovel, for sucking in the Air, which must be luted to it ve∣ry firmly.

B, is the Inside where the Ashes fall into; this ought to be lofty for drawing the Air.

C, is the Grate, and must be of very strong Iron Bars.

[illustration]

D, is the Opening through which the Crucibles and Fuel is put in, this ought to be of well temper∣ed Iron, and luted within side with very good Lute, at least three Inches thick.

E, is the Chamber where the Works are Ba∣ked.

F, is the Coverlid of the Furnace, which is to be Vaulted firm, and made of the same Earth.

G, is the Chimney, over which you may set se∣veral Iron Plates one above t'other, for drawing the Air.

H, is the Hovel, or shelving place of Iron for the Ash-Hole.

I, are Funnels for the Chimney Plates, and the Hovel.

K, is a Crucible.

If this Furnace be made five or six Inches thick, it will bear all degrees of heat, and serve very conve∣niently for Private Persons, by making it of a suita∣ble largeness instead of the Glass-house Furnace: When you make your Fire of Wood, there will be no occasion for the Hovel of the Ash-hole. But to go on with our Pearl.

You must take two Pound of thrice distilled Vi∣negar, one Pound of Venice Turpentine, mix them together, and so put the Mass into a Glass Cucurbit; fit to it the Head and Receiver, luting the Joynts; let them dry, and so set it on a Sand-Furnace to di∣stil the Vinegar; keep a gentle heat, lest the Stuff swell up.

Afterwards put the Vinegar into another Glass∣Cucurbit, wherein you must hang a quantity at dis∣cretion, of Seed Pearl, strung on a Thread of Sil∣ver or Gold, done about with a piece of very thin Silk; these must hang in the middle of the Body, so as not to touch the Vinegar: This done, head

your Cucurbit with a Blind Head, and lute it very well; set it in a moderate B. Mariae well closed, there to remain for a Fortnight; the heat of the B. will elevate the Fumes of your Vinegar, and they'll continually circulate about the Pearl, and so soften and bring them to the Consistence of a Paste, which being once performed, take 'em off and mould them up in what Form you please, round, long, or Peaalike, and as big as you think fit; do this with Moulds of fine Plate gilded within; you must not touch the Paste at all with your Hands, but altoge∣ther Work it with a Plate Spatula, which will fill the Moulds, then bore them through with a Porkers Bristle, or Gold-Wire, and so let them dry a little; then Thread them again with Gold-Wire, and set them in a closed Glass, which lay in the Sun, to dry them to a hardness; set them afterwards in a Glass Matrass, in a Stream of Running Water, leaving it there for twenty Days; and about that time they as∣sume their first solidity and hardness.

To give them Transparency and Splendour, you must prepare some Mercury-Water, after the Rate we shall prescribe in the next Chapter. When you have taken them out of the last Matrass, wherein they were for twenty Days, as the Running Water▪ hang them in a Vessel of Glass where the Mercury-Water is, and so they'll moisten, swell, and assume their Oriental Beauty: This done, shift them out of this Water into a Matrass closed Hermetically, for fear that any Water should be admitted into it, and so down with it into a Well, leaving it there for eight whole Days; then draw it up, open the Matrass▪ and you'll have them as fine and good as any Orien∣tal Pearls whatsoever.

This Method is a little long, but withal 'tis effe∣ctual and sure; however 'tis not thus the Philoso∣phers,

or Virtuosi Work, for they have another Way, much shorter, having regard only to one Spi∣rit; nor have I Experience enough in their Matters, to make a Discovery thereof; and if I had, it cou'd not be done without disobliging them irreconcila∣bly; therefore take what I have delivered on this Important Subject, in good part; and be assured, that if you were acquainted with that Secret which they so closely reserve, there could be nothing done more by it as to Goodness and Beauty in this Work, than by our prescribed Method, which is very e∣stimable, and more precious than you'll imagine, whereof I can assign you no better, or other Argu∣ment, than Experience, to convince you.

CHAP. CCXLIV. To make Mercury-Water for giving Transparency and Splendour to the Pearls.

HAVING promised this Secret of making Mer∣cury-Water to compleat the Transparency, and Natural Lustre of your Pearls, which is a Mat∣ter so highly valuable, that a very considerable Sum has been offered in our Presence, for the Discovery thereof, to a certain Person; yet we are free, that Ex∣perience should have its due course of informing the Ignorant, and shall, for our part, generously acquit our Engagement.

You must take Plate Tin of Cornwall calcined, let the Calx be very fine and pure, amalgamate one Ounce thereof, with two Ounces of prepared Mer∣cury well purified; wash the Amalgama with Wa∣ter, until the Water remains clear and insipid; then drying the Amalgama throughly, put it into a Ma∣trass

over a Furnace, keeping such a degree of heat as is required for Sublimation; when the Matter is well Sublimated, take off the Matrass and let it cool, and so take out the Sublimate; to which add one Ounce of Venice Sublimate and grind them well to∣gether on a Marble, so put them into another Ma∣trass, close it very well, and set it topsy-turvy in a Pail of Water, and the whole Mass will resolve its self in a little time, all into Mercury-Water: This done, filter it into a Glass Receiver, and set it on a gentle Ash-Fire to coagulate, and it will be brought to a Crystalline Mass; take it 〈◊〉〈◊〉, and with a Glass Pestle and Mortar pound it very well to a very fine Powder, which searce through a fine Searce, and put it into a well stopt Matrass in B. Mariae, let∣ting it remain till it resolve again into Water; and this last shall be the Mercury-Water which you must preserve to employ on your Pearl.

CHAP. CCXLV. Another Way to make these Pearls.

THIS is an easier way than the former, for by Baking them, (as we shall shew) you very much shorten the time which the Preparation would else take up; however you must not expect them so De∣licate and Natural as the first, the Cause whereof is easie enough conceived; for these Pearl having en∣larged themselves in the Water, as we already no∣ted, 'tis reasonable to believe the hardning them af∣terwards in the Cold, will be of a much more Na∣tural Effect, than if done with heat.

Take very fair Oriental Seed Pearl for this pur∣pose, and reduce it to impalpable Powder on a Mar∣ble,

to dissolve afterwards in Mercury-Water, or clarified Juice of Lemons; if this be not effected quick enough, set it in a Cucurbit over warm Ashes, and be very careful to take the Cream (which in a little time will appear at top) immediately off, so withdraw the Dissolution from the Fire, and let it settle a little; this done, pour it gently into ano∣ther Glass Body, and keep it a-part, you'll have the Pearl in a Paste at the bottom, with which fill your gilded Plate Moulds, made to what bigness, or form you think fit, pressing the Paste with the Silver Spa∣tula, and so shut them up four and twenty Hours; after you must take and bore them through with a Porker's Bristle, close up the Moulds, and leave them in the Oven in a Paste of Barly Dough, which being half Baked draw out and open, taking away all the Pearl, and steep them in the Dissolution just before directed to be kept a-part, putting them in and out several times; so close them in their Moulds and Bake them again with the like Paste as before, only let this last be almost burnt up before you draw it out; thus you'll have the Pearl well baked and hardned.

This done, draw it out, open all the Moulds, take away the Pearls and string them on one or more Gold or Silver Threads; steep them in Mercury-Water, given in the former Chapter, for about a Fortnight; after this dry them by the Sun in a well closed Glass Body, so you'll have very fine and splen∣did Pearl.

CHAP. CCXLVI. Another Way.

THO this be a more common way than the pre∣ceding, we will not omit it, because every one may have his choice to take that Method which best suits with his Apprehension, or Conveniency.

You must, as in the former, take very fair Ori∣ental Seed Pearl ground to an impalpable Powder▪ and dissolve it in Allom-Water, then rack off that Water, and wash the Paste of Pearl which remains at bottom, first with some distilled Waters, then i•• Bean-Water, and set it in B. Mariae, or Horse-dung, to digest for a Fortnight; afterwards take out your Vessel, and the Matter being come to the Consistence of a Paste, mould up the Paste in the gilt Silver∣Moulds, as before directed, bore them with a Bri∣stle, string them on Gold or Silver Thread, and hang them in a very well closed Limbeck of Glass to prevent the Air from coming in to spoil them.

Thus dried lap them one by one in Leaves of Sil∣ver, and split open a Barble, as if you were to Fry him, and so close them all up in his Body, make a Paste of Barly-Meal, and Bake him in it, as you would a Batch of Bread, and no more, afterwards draw it out, and let them dry.

To give a Transparency and Splendour to these Pearls; if you don't care for using our Mercury-Water, instead thereof, take the Herb Grati•• squeezed in Water, put into this Water six Ounces of Seed Pearl, one Ounce of Salt-peter, an Ounce of Roch-Allom, an Ounce of Litharge of Silver; the whole being dissolved, take your dried Pearls, heat

them first, and then cool them in this Dissolution; thus do for about six times at least, heating and cooling them at this rate therein.

If your Pearl should happen to fail of coming to a sufficient hardness, you may correct and make them exceeding hard by Baking them a second time after this manner.

Take two Ounces of Calamy, or Lapis Calamina∣ris, in impalpable Powder; add to this two Ounces of Oyl of Vitriol, and two Ounces of the Water of White Eggs; put all these into a Retort, lute thereto a Receiver, and let them distil, you'll have from them a very fair Water, with which, and some very fine Barly-Meal, make a Paste, Coffin your Pearls in this, and Bake them in an Oven as before, they'll thus become exceeding hard, and recover their Natural Transparency.

There are many other Ways very good to make Pearl with Oyls, which add to the Growth and Largeness of the Seed Pearl, as much as you will have them, but all these Preparations being very te∣dious, and our Book large enough already, we are of Opinion, 'tis best to let them alone for the pre∣sent; besides, we have said enough to hand the In∣telligent Readers to those Secrets discoursed off, and taught them herein, reserving the more enlarged and fuller Instructions for the first Edition we make hereof in two Volumes.

CHAP. CCXLVII. How to blanch fine Pearl.

THE Beauty of Pearl consists entirely in the Brightness of their White Colour, such as are Spotted, or of a dark Yellow, being the least estimable; you may however restore these last to a true Luster and Whiteness, by letting them soak and cleanse first in Bran-Water, then in Milk-warm Water, and last of all steep them twenty four Hours in the Mercury-Water assigned Chap. 244. This done, string and hang them in a well closed Glass Body, to dry in the Sun, as before.

The Bran-Water is made by boiling two good Handfuls of Wheaten-Bran in a Quart of Water, until the Water has drawn all the Strength thereof to it; and thus you are to use it afterwards for cleansing the Pearl; you must string and lay them all together in a glazed Earthen Pan, and pour there∣on one third of this Water, when they have soaked, until the Water be tolerably cooled, that you may endure the heat, rub them with your Hands gently to cleanse them the better; continue so until the water be cold, throw out this cold water, and pour on another third part of the Bran-water still boil∣ing, and so use it as the former, throwing it away when cold, and then pouring on the remainder of the water, proceeding still after the former man∣ner; after this, just heat some fair water, and pour it on them, to refresh and take away the Remains of the Bran; shift this water, pouring on more fresh warm water; do thus thrice without handling them, then lay them on a Sheet of very clean white Paper,

to dry in a Shade, and last of all steep them in your Mercury-water, to bring them to Perfection.

CHAP. CCXLVIII. Another Way to Blanch and Cleanse fine Pearl.

THERE are several other easie ways to cleanse and whiten the Pearl, which may serve on in∣different occasions, and for ordinary uses.

Pound Alabaster to impalpable Powder, and rub the Pearl with it very gently, this will cleanse them, or you may let them remain in this Powder twenty four Hours afterwards, they be still much the better for it.

VVhite Coral has also the same Effect as the Ala∣baster, using it after the like manner.

Tartar calcined white, and divested of all its moi∣sture, as we have shewn elsewhere, is very good for the same use.

Clary, or Old Salt dissolved, filter'd, coagulated, well dried and ground, is as effectual as any of the former things, for cleansing and blanching of Pearl, by rubbing them therewith a considerable time; you may afterwards lay them up in some Millet ground large, and it will contribute to them a Natural Brightness.

There are several other ways to cleanse and whi∣••en Pearl, but those we have here proposed, are suf∣••icient.

CHAP. CCXLIX. To make Counterfeit Pearl, very like the Natural.

THIS Receipt for making Counterfeit Pearl has a much more fine and solid effect than any now a-days in use.

Take Chalk well purified, and separated from its grossness and Sand, make Paste thereof, and so mould it up like Pearl in a Mould for that purpose; pierce these through with a Bristle, and let them after∣wards dry before the Sun, or for more dispatch in an Oven, till they receive a just hardness; then string them on a very fine Thread of Silver, colour them over lightly with Bole-Armoniack, diluted in water of VVhites of Eggs, then drench them with a Pencil and Fair water, and so apply Leaf-Silver all over, and let them dry; this done, burnish them with a VVolf's Tooth, till they shine very finely.

To give them the true Colour of Pearl, make a Glue of Parchment, or rather Vellom Shavings; thus Wash the Shavings in warm Water very well, and boil them after in a new Pot to a thickness, and strain this Glew.

When you use this Glue, you must warm it on •• flat Vessel, then dip the string of Pearl therein, so as not to fill the interval Inches between each Pearl but that every one may be done all over equally; a••∣ter this let them dry; if you observe any Baulk, 〈◊〉〈◊〉 Defect on them, you may dip them in a second time•• thus they'll assume a finer and more transparen•• Whiteness, and will have a certain Darkness within and Lustre on the outside, which compleats and

••rings them to the Natural Beauty of real fine Pearl.

You may after this manner do with Transparent Beads of Alabaster, and very white Mouth-Glew, and it will add very much to their Beauty; but Leaf Silver does certainly contribute most of any thing else whatever to their Splendour.