Proponent of earlier made source The art of glass, Book II
To extract the salt of Polverine, Rochetta , and Ba-rillia , wherewith Crystall Fritt called Bollito is made.
The foundation of the Art of Glass- work, with a new and secret way.
Olverine, or Rochetta, which comes from the Levant and Syria, is the ashes of a certain herb growing there in abundance : there is no doubt but that it makes a far whiter salt than Ba-would make a Crystall very perfect and beautifull, make it of salt extracted from Polverine or Rochetta of the Levant. For though Barillia yield more salt, yet Crystall made therewith alwaies inclines to a blewness, and hath not that whiteness and fairness as that made of Polverine hath.
The way often by me practised to extract the salt perfectly from both of them, is this which follows.
Powder these ashes, and sift them with a fine sieve, that the small pieces go not thorow , but onely the ashes ; the finer the sieve, the more salt is extracted. In buying of either of these allies, observe that they abound in salt; this is known by touching them with the tongue, and rafting what salt they contain: but the safest way of all is, to make an essay of them in a melting-pot, and to fee whether they bear much sand, or Tarso, a thing common in this Art, and which the Conciators very well know.
Set up brass coppers with their surfaces like those of the Dyers, greater or lesser, according as you have occasion to make a greater or lesser quantity of salt: fill these coppers with fair and clear wa¬ter, and make a fire with dry wood, and when the water boyleth well, put in the sifted Polverine in just quantity and proportion to the water, continue the fire and boyling till a third part of the water be consumed, alwaies mixing them at the bottom with a scummer, that the Polverine may be incorporated with the water, and all its salt extracted; then fill the coppers with new water, and boyl it till half be consumed, and then you have a lee impregnated with salt. But that you may have salt in greater quantity, and whiter,
put into the coppers when they boyl, before the Polverine is put in, about 12 pound to a copper of Tartar of red wine, calcined only to a black colour, dissolve it well in the boyling water , mingling it with a scummer, then put in the Polverine. This way of Tartar is a secret, and makes more, and whiter salt, and a more beautiful Crystall. When two thirds of the water is evaporated , and the lee well impregnated with salt, slacken the fire under the copper, and have in order many earthen pans, at first filled with common water for six daies, that they may imbibe less lee and
salt, and then with great brass ladles, take the lee out of the copper, and put it into the said pans, take out also the ashes from the copper, and put them all into the same pans, and when they are full, let them stand so ten daies, for in that time the ashes will be all at the bottom, and the lee remain very clear, then with brass ladles, take gently (that the bottom be not raised, and troubled ) the clear lee, and put it into other empty pans, and so let the lee stand two daies, which by the setling of more terrestriety at the bottom, becomes very clear, and limpid, let this be thrice repeated, and you shall have the lee most limpid, and discharged of all terrestriety, wherewith a very fine and perfect salt is made. Let the coppers be filled again, and boyl with the same quantity of Tartar, and then the Polverine as before; continue this work till you have materials enough.
To strain the said lees, and extract the salt, first wash the coppers well with clear water, then fill them with the said refined and clarified lees, and make them boyl softly, as before, and observe that you fill the coppers with the said lee, till you see it thicken, and shoot its salt, which is wont to be about the beginning of 24 hours, for then in the superficies of the copper , you will begin to see white salt appearing like a spiders web, or white thread, then hold a scummer full of holes at the bottom of the copper, and the salt will fall upon it, and now and then take it out, suffering the lees to run out well off it into the copper, then put the salt into tubs, or earthen pans, that the lee may
be better drained, the liquor that drains must be saved, and put into the copper, then dry the salt. Continue this work till all the salt be gotten out of the copper: but you must observe, when the salt be¬gins to shoot, to make a gentle and easie fire, for a great fire makes the salt stick to the copper, and then the salt becoming strong, alwaies breaks the copper, which thins hath sometimes hapned to me ; wherefore observe this chiefly, using great patience and diligence. The salt in the pans, or tubs, being well drained, must be taken, and put into wooden tubs, or vats, the better to dry out all the moysture, which happens in more, or fewer daies, according to the season in which it is made.
The fecret then of making much, and good falt, confifts in the Tartary as is before demonfrated. From every three hundred pound of allies, I ufually get from 80 to 90 pound of falt. When the falt is well dryed, beat it grofsly, and put it into the Calcar to dry, with a molt gentle heat, and with an iron rake it mull be broken, and mixed as the Fritt is when it is well dryed from all its moifture, ob-ferving alwaies that the Calcar be not very hot, but temperate, take it out of the Calcar, and pound it well, and fift it fo, that the greateft pieces which pafs tho-row, exceed not the bignels of a grain of wheat.
This fait thus pounded , fifted and dryed, muft be kept by it felf, in a place free from dud, for to make Fritt of Cry-ftall: the way to make this Fritt is this which follows.
The way to make Fritt for Crystall, otherwise called Bollito.
CHAP . II.
When you would make fair, and fully perfect: Crystal, see you have the whitest Tarso, which hath not black veins , nor yellowish like rust in it. At Moran they use the pebles from Tesino, a stone abounding in that River. Tarso then is a kind of hard, and most white mar¬ble, found in Tuscany, at the foot of the Verucola of Pisa, at Seraveza, and at the Massa of Carara, and in the River Arnus, above and below Florence , and it is also well known in other places. Note, that those stones which strike fire with a steel are fit to vitrifie , and to make glass and Crystall, and those which strike not fire with a steel, will never vitrifie, which serves for advice to know the stones that may be transmuted , from those that will not be transmuted into glass.
Take then of the belt Tarso, pounded B 4 small, and serced as fine as flower, 200 pound; of salt of Polverine pounded, and sifted also, about 130 pound, mix them well together, then put them into the Calcar, which at first must be well heated , for if they be put into the Calcar when it is cold, Fritt will never be made of them. At first for an hour, make a temperate fire, and alwaies mix the Fritt with the rake, that it may be well incorporated , and calcined, then the fire must be increased, al-
waies mixing well the Fritt with the rake, for this is a thing of great importance, and you must alwaies do thus for 5 hours, still continuing a strong fire.
The Calcar is a kind of calcining; furnace, the rake is a very long instrument of iron, wherewith the Fritt is continually stirred ; both these are very well known, and used in all glass furnaces. At the end of 5 hours, take the Fritt out of the Calcar, which in that time (having had sufficient fire, and being well stirred ) is made and persected. Then put this Fritt in a dry place on a stool, and cover it well with a cloath, that no dust nor filth may fall upon it: for herein must be used great diligence, if you will have good Crystall. The Fritt thus made, becomes as white as snow from Heaven. When the Tarso is lean, you must add somewhat more than ten pound of the salt to the quantity aforesaid. Wherefore let the experienced Conciators alwaies make tryal of the first Fritt, by putting it into a chrysible, which being put into the furnace, if it grow clear, and suddenly, they know whether the Fritt be well prepared, and whether it be soft, or hard, and whe¬ther the quantity of salt is to be increased, or diminished. This Crystall Fritt must be kept in a dry place, where no moisture is, for from moist places, the Fritt suffers much, the salt will grow moist, and run to water, and the Tarso will remain a¬lone, which of it self will never vitrifie : neither is this Fritt to be wetted, as others are. And when it is made, let it stand 3 or 4 months, and it will be much better to put into the pots, and sooner waxes clear. This is the way to make Crystall Fritt, with the dose and circumstances, which I have oft times used.
Another way to extract the salt of Polverine, which makes a Crystall as fair and clear as natural Crystall: This was my indention.
CHAP . III.
Take Polverine of the Levant well serced, and put it into great glass bodies, luted at the bottom, with ashes, or sand, into the furnaces, filling them at first with common water, give them a temperate fire for some hours in the furnace, and let them stand till half the water be evaporated ; the furnace being cold, gently decant off the water into earthen pans glased, putting new water upon the remainder of the polverine, and let it boil ( as before) this is to be repeated till the water hath extracted all the salt; which is known, when the water appears to the tast not at all saltish, and to the eye when it is void of colour. Take of these Lees what quantity you will, let them be filtred, and stand in in glased pans four or six days to settle, which by this means will leave a great part of their terrestriety, then put them to filtre anew , thus will they be purified, and separated from a great part of their terre-striety, then let these Lees be set to eva¬porate in great glass bodies, luted at the bottom, in furnaces, in ashes, or sand, at a gentle fire , and at last when the stuff is dryed, observe that ye fire be very gentle, that the salt be not burned nor wasted.
When the salt is dried; take out the glass bodies and see if they be broke at the bot¬tom, which is wont to happen often, in which case put the said salt into other good glasses, well luted at the bottom, and fill them at the top with common pure and clean water, which set in the furnace, in a¬
shes or sand, at a gentle fire, and always evaporate an eighth part of the said water, then, the furnace being cold , empty this water fully impregnated with salt into earthen pans glased, and when the water is setled 24 hours, filtre it with diligence, that the salt may be separated from the rest of the terrestriety and dregs, let this lee be evaporated in glass bodies with a gentle sire, and at last more gentle, that the salt be be not burned, put this salt again into glass bodies to be dissolved in common water, in every thing as before repeat this work, till the salt yields no more terrestriety, or dregs, then shall you have a pure and per¬fect salt wherewith a Fritt made with Tarso as before, will make a Crystall, which in fairness, whiteness, and cleerness, will excel natural Crystall.
An observation for Gold Yellow , in Crystall.
CHAP . IV.
Observe that when salt of Tartar is mixed with salt of Polverine, Fritt made of the said salt is not good to make, nor can make, a Gold yellow, although it make all other colours. But to make your Gold yellow , you must make Fritt with salt taken from Polverine alone, first purified as above, for otherwise this yellow will not arise. Although this process be somewhat laborious, and a small quan¬tity of salt made therewith, yet not-with-standing it will make a Crystall worthy of all great Princes, being fit to make all sorts of vessels and works. This was my invention, whereof I have many times made trial with happy success and my great content.
The way to make salt of Fern, which makes a Very fair Crystall.
CHAP . V.
In Pisa I made experience of Fern-ashes which groweth in great abundance in Tuscany, which herb must be cut from the earth, when it is green, from the end of May to the midst of June, and in the Moons increasing, when it is near it's op-position with the Sun ; for then the said herb is in it's perfection, and will then make more salt, and of a better nature, strength and whiteness, than at other times: for when it is suffered to dry of it's self upon the ground it yields little salt, and of little goodness. This herb being thus cut and laid together, soon wi¬ther- thereth , then let it be well burned to ashes, with these ashes, and with the rules, observations, and diligence given before for the salt of the Polverine of the Levant, is extracted a pure and good salt, wherewith I have made Fritt with good and well serced Tarso, the which Fritt melts well in the pot, and yieldeth a fair Crystall, and much better than the ordina¬ry Crystall, because it had more strength and bended much better, which the ordinary Crystall doth not, it is drawn into fine threads, such as I caused to be drawn, and to this Fritt may be given a wonderful yellow Gold colour, observing that there be in it no salt of Tartar, for neither from this will the Gold yellow arise , and the Gold yellow which is given to this Crystal is much fairer and pleasanter than can be wrought with the Crystall made with the salt of the Levant Polverine, and with that Crystall cannot be made all sort of works as with the other.
The way to make another Salt which will produce a marvelous and won¬derful Crystall.
CHAP . VI.
If there be made ashes after the manner aforesaid, of the Cods and Stalks of Beans, dried in the summer, when ye husbandmen have thrashed and separated the Beans, with which ashes, with the rules and pains abovesaid in the salt of Polverine, a marvellous salt is extracted, wherewith is made a very noble Fritt with white and well serced Tarso, which in pots will make most beautiful Crystall ; the same may be done with the ashes of Cole-worts, Bramble Berry bush, and also with stalks of Millet, Rushes, and fen Reeds, and many other herbs which yield a salt, where- with ( making Frits after ye accustomed manner) will be made most beautiful Crystall, as every noble and curious spirit may try by experience, for thereby more is learned than by Iong study.
A salt that will make a very fair Crystall.
Chap . VII.
Take the salt of Lime which serves for building , and this salt purified and mixed with the ordinary salt of Polverine of the Levant about two pound to a 100. that is two pound of salt of Lime to a 100 pound of the salt of Polverine purified and well made ( as abovesaid ) with this salt so mixed is usually made ordinary Fritt, and is put in the pot to clarifie, as shall be hereafter declared in the way of making of Crystalline, Crystall, and common glass, and so thus made a very fair and beautiful Crystall.
The way to make ordinary Fritt, to wit of Polverine, Rochetta, and Barillia of Spain.
Fritt is nothing else but a calcination of those materials which make glass, and although they may be melted, and make glass without calcination, yet this would succeed with length of time and weariness, and therefore this calcination was invented to calcine the Fritt in the Calcar, which, when it is calcined , and the proportion of the materials is adjusted agreeable to the goodness of the Barillia, presently melts in the pot, and wonderfully clarifies.
Fritt made of Polverine makes ordi¬nary white glass; Fritt from Rochetta of the Levant makes the fairest glass called Cry¬
stall ; Barillia of Spain, though it be u-sually fatter than the former, yet it makes not a glass so white and fair as that of the Levant, because it always inclines a little to an azure colour.
To make then Fritt, serce the Polverine thorow a fine serce, the small pieces which pass not, let them be pounded in stone mortars, the like is to be done with the Rochetta and Barillia, to wit every one by it's self, and be sure that they be well pounded, and serced thorow a fine serce; for as the common proverb in this art saith, A fine serce, and dry wood, bring honour to the furnace. Now whatsoever the quan¬tity of the Barillia be, for example, a 100 pound of it commonly requires, from 80 pound to 90 of Tarso, which must be finely
beaten, and then finely serced, more or less, according to the goodness of the Barillia, and it's fatness, where of you need not make an essay, how much it holds as is known by art. Then with sand, and espe. cially with that from Tuscanie found in the vale of Arms, being much fatter,and having in it more plenty of salt, than Tar¬
so hath. There is never added more than 6 or 8 pound to the hundred. Now this sand must be washed from all it's unpro-fitable terrestriety, and serced, and then this will make a white and good glass; for Tarso always makes much fairer glass than any sand that is in Tuscany. The due quan¬tity
tity of sand or Tar so, being found out, mix and unite them , first well together with the Barillia or Polverine well sifted, and so put them into the Cilcar when it is hot, & at first mix & spread them well in the Cal¬
car, with a rake, that they may be well calcined, and continue this till they begin to grow into lumps, and come into pieces as big as small nuts. The Fritt will be well and perfectly wrought in the space of 5 hours, being stirred all that time and a sufficient fire continued , and when you would fee whether it be well made, take a little of it out, when cold, if it be white, yellowish and light, then 'tis made. The calcining of it more than 5 hours is not amiss ; for by how much more it is wrought and calcined, the better it is, and the sooner it melteth in the pot, and by standing a little longer in the Calcar it con-sumeth and loseth the yellowness and foul¬ness which glass hath in it self, and it be¬comes more clear and purified. When the Fritt is taken out of the Calcar thus hot, let there be thrown upon it 3 or 4 pails of cold water, then set it under ground, in a moist and cold place, and the filth which arose when the salt was made ( as is a¬
bove said ) is wont to be put into the same pans, with the lee from Polverine ; fill them with common water, having tubs Under the pans to receive the water, which by little and little drops thorow the said filth and setlings, and hence comes a very strong pure and clear lee to be kept apart, and herewith now and then water the Fritt abovesaid, which being heaped together in a moist place the space of 2 or 3 moneths or more ( the longer the better) then the said Fritt grows together in a mass as a stone, and is to be broken with mattocks. Now when it is in the pot it soon melteth stupendiously, and maketh glass as white as Crystall. For this Lee leaves upon the Fritt it's salt which worketh this effect. When this Lee is not to be had it must be water¬
ed with common water, which although it doth not work this great effect as the laid lee, yet it doth well, and maketh it ea¬sier for melting. Wherefore Fritt should stand,when made, some moneths. which thus made alway causeth less wood to be consumed, and the glass clear and sweeter to work.
To make Crystall in full perfection, the way I always practice.
CHAP . IX.
T Ake Crystall Fritt diligently made, set it in pots in the furnace , where there are no pots with colours, for the fumes of metalls whereof the greatest part of co¬lours are made, make the Crystall pale and foul, but that it may come forth white, shining, and fair, when you put the Fritt into the pots in the furnace, then cast in such a quantity ot Manganese prepared as is needful, according as the pots are, greater or less. For this lieth in the pra¬ctice of the able and diligent Conciatore, and belongs to his office. The quantity of the Manganese and of all other colours to be put into the Fritt and metalls cannot be precisely determined either by Weight or measure, but must be wholly left to the e and judgement, tryal and experience of the Conciatore. To make a fair Crystal, when it is Well melted take it from the pots, and east it into great earthen pans , or clean bowls ful of clean water(for it requireth to be cast into water) to this end that the water may take from it a sort of salt called Sandever, which hurteth the Crystall, and maketh it obscure and cloudy, and whilst it is a working still casteth forth Sandever, a thing very foul.Then put it again into a clean pot, and cast it into water, which is to be re¬peated as often as is needful, until the Crystal be separated from all this salt, but this is to be left to the practice of the Conciator, then set it to boil 4 or 6 days, and let as little Iron be mixed therewith as is possible,for it gives it always a black¬ish tincture. When it is boiled and clear, see whether it hath enough Manganese , and if it be greenish, give it Manganese with dis¬cretion. Wherefore to make good Crystall put in the Manganese by little and little at a time,for it makes the Crystall of a murry colour, which afterward inclines to black, taking from it it's splendor; mix the Man¬
ganese , and let the glass clarifie till it be¬comes of a clear and shining colour. The property of Manganese is, being put in just quantity to take away the foul greasines which Crystall always hath,and to make a
resplen-The first Book. 23 resplendent white, when the Crystall is clear limpid & fair, work it continually into vessels and works that most please you, but not with so great a fire as common glass is wrought with. Be careful that the Irons wherewith you work be clean, and that you put not the necks of the glasses where the Irons touch (for there always remaineth Iron ) into the pots of Crystall , for they make it become black. But this glass where the Iron rods touch may be put in to make
glass for vulgar works.
To make Crystall-glass, and white, called otherwise commong lass.
FRitt of Polverine makes a white and fair common glass, Fritt of Rochetta makes the fairest glass called Crystall, which is between ordinary glass and Cry¬stall. As much Manganese prepared must be used in common glass as is in Crystalline ;
cast the Crystalline or common glass once at least into water, that you may have them fair, clear, and in perfection. Although glass may be made without this casting into water, yet to have it fairer than ordi¬nary, this is necessary to be done, and may be repeated according to your pleasure, as you would have them more resplendent and fairer, and then you may work them into what vessels you need. And to make them yet whiter,Calcine them that they pu¬
rifie well and have but few blisters. And a¬bove all observe,that if to each of them, by themselves, you put upon the Fritt, the proportion of 12 pound of salt of Tartar pu-rified to a 100 weight of Fritt, it makes them without comparison fairer, and more pliable to work than ordinary. The salt of Tartar must be put in when the Fritt is made, and then be mixed with Tarso, or sand, together with the Polverine or Rochet-ta sifted, and then make thereof Fritt as before.
To make Purified salt of Tartar, for the work abovesaid.
CHAP . XI.
Tke Tartar of red wine in great lumps, and not in powder, Calcine it in earthen pots between live coles till it be¬come black, and all it's unctuosity be burned away, and till it begins to grow white, but let it not become white, for then the salt will not be good. Put
the said Tartar thus Calcined into great earthen pans full of common water heat- ed,as also into earthen pots glased, & make it boil with a gentle soft fire in such sort that a quarter of the water may be exha¬
led in two hours, then take them from the fire, and suffer the water to cool, and be¬come clear, which decant off, and it will be a strong lee, then put in more common water into the said pans after the same manner, and upon the remainder of the Tartar, and let them boil as before, repeat this until the water become no more sal¬
tish tish, then Filtre these waters impregnated with salt, and put the clean Filtred lee into glass bodies to evaporate in the ashes of the furnace at a gentle heat, and in the bottom there will remain a white salt, dis¬
solve this salt in warm water , let it settle two days, then evaporate it in glass bodies at a gentle heat, and there will remain at the bottom a salt much whiter than at the first time, dissolve this salt again, and at¬ter two days setling, Filtre and evaporate it in every thing as before. Repeat this manner of dissolving,Filtring, evaporating this salt of Tartar four times, which then will be a salt much whiter than snow, and purified from the greatest part of it's Terrestriety, which salt mixed with Polverine or Rochetta serced with a dose of Tarso or sand will make a Fritt, which in the pot will yield Crystalline and common glass much fairer than that that is made without the addition of this salt of Tartar, and although a fair Crystalline may be made without it, yet notwithstanding a much fairer may be made with it.
To prepare Zaffer which serves for many colours.
CHAP . XII.
T Ake Zaffer in gross pieces , put it into earthen pans, let it stand half a day in the furnace, & then put it into an Iron ladle to be heated red hot in the furnace , take it thence thus hot and sprinkle it with strong vineger, as soon as 'tis cold grind it fine on a Porphyrie stone, wash it in earthen pans glased, with much warm water, always suffering the Zaffer to settle to the bottom then decant it gently off; th is will carry a¬way the foulness and Terrestriety from the Zaffer, and what is good, and the tincture thereof will remain at the bottom , which
thus prepared and purified will tinge much better than at first, making a limpid and clear tincture, which dry and keep in vessels closed for use.
To prepare Manganese to colour glass.
CHAP . XIII.
TAke Manganese of Piemont, for this is the best of all the Manganeses at this day known in the art of glass. At Venice there's not alwayes plenty , and at Moran none other is used. In Tuscanie and Liguria there's enough ; but that holds much Iron, and makes a black foul colour. That of Piemont mikes a very fair murry , and at last leaves the glass white, and takes away the greenness and blewness from it. Put this Manganese in pieces into Iron ladles,
and proceed thorowout as in preparing Zaffer.
es to colour glass. CHAP. XIV.
To make Ferretto is nothing but a simple Calcination of Copper , that the metall being opened , may communi¬cate it's tincture to glass; which Calcina¬tion when it is well made without doubt makes divers and very beautiful colours. This Calcination is made many ways,I shall set down two of them, not only easie but of times used by me, with effects very fair, in glass, whereof the first is this that fol- loweth, to wit, Take thin Copper-plates of the bigness of a Florentine, and have one or more melting pots of the Goldsmiths, and in the bottom of these pots make a layer of brimstone powdered, then a layer of the said plates, and over them another layer of powdered brimstone, and another of Copper-plates,as before, and in this or¬der fill the pot, which is otherwise said to make a S S S. cover and lute well, and
dry this pot, and put it into an open wind furnace amidst burning coals, and a strong fire must be given to it for 2 hours, let it cool, and you shall find the coppcr Cal-cined, and it will be broke in pieces by the fingers as if it were dry earth, and will be raised into a black and reddish colour. This Copper being beaten small and serced in a fine serce is kept well closed for use.
Another way to make Ferretto of CHAP . XV.
T His second way of making burnt Cop¬per, though it be more laborious than the first, yet it will do it's effects in glass more than ordinary.
The Copper then ( instead of making a SSS with Brimstone) must make a SSS with Vitriol, and then Calcine it, letting it stand three days in the floor of the furnace, neer the occhio, then take it out & make another SSS with new Vitriol, keep it in reverberati¬on as before,& this Calcination with Cop¬peras
peras must be repeated six times, and then you shall have a most noble burnt Cop¬
per, which in colours will work more than ordinary effects.
make Crocus Ferri, otherwise called Crocus Martis, to colour
CHAP . XVI.
ROCUS Martis is nothing else but a sub¬tilising and Calcination of Iron, by means whereof it's tincture (which is most red in glass) is so opened that it communi- cateth it's self to glass,& not only manifest-eth it self,but makes all other metalline co¬lours (which ordinarily are hidden and dead in glass) appear fair and resplendent; I will set down four ways to make it, and the first is.
Take filings of Iron (if you can have them, those of steel are better ) mix them well with three parts of powdered brim¬
stone, and keep them in a melting pot in a furnace to Calcine, and burn well off all the brimstone, which soon succeeds, let them stand four hours in burning coals, then take and powder , and serce them thorow a fine serce, and put them in¬to a Chrysible covered and luted at the top, & set them in the Leer of the furnace neer the occhio or the cavalet 15 days or more which then gains a reddiss Peacock-like colour, as if it were purple, this is kept in a close vessel, for the use of glass colours, for it worketh many fair feats.
The second way to make Crocus Martis.
T His second way of making Corcus Mar- tis, with so much ease,ought to be much esteemed of, since the Crocus made in this manner makes appear in glass the true red colour of blood,and the manner of ma¬
king it is thus,
Take filings of iron (steel is better ) mix them well in earthen pans with strong vineger, onely sprinkling them so much that \
that they may be wet thorowout, spread them in pans, and set them in the sun till they be dry, or in the open air when the sun is cloudy. When dry, powder them, and if they be any whit in lumps, sprinkle them with new vinegar, then dry and pow¬
der them as before, repeat this work 8 times, then grind and serce them fine , and you have a most fine powder of the colour of brick powdred, which keep in vessels to colour glass.
A third way to make Crocus Martis.
CHAP . XVIII.
T His third way of making Crocus Mar- tis, is a way by which the deep co¬
lour of Iron is made more manifest than may seem credible, and in glass is seen the truth and proof thereos. Sprinkle filings of steel with Aqua-fortis, in glased pans, set them in the sun to dry, powder them, wee them again with Aqua-fortis and dry them, repeat this several times, and you shall D have 34 The first Book. have a red powder, as is said of Crocus made with Brimstone , then powder, serce, & keep it for your use to colour glass.
A fourth way to make Crocus Martis.
CHAP . XIX.
His is the fourth and last way to make Crocas Martis, and perhaps the best of all, though each of the ways shown by me, are not onely good and perfect in their operation, but necessary also for divers co¬lours necessarily & daily made in glass,&to make this, dissolve in Aqua-fortis made A- qua-Regis, with Sal Armoniack ( as shall be said in our rules of Calcidony) filings of Iron or steel in a glass vessel well closed , keep them so 3 days,& every day stir them well. Observe,when the said water is put upon the filings,that it be done leasurely, & wari¬ly, because it riseth much, and endangereth the breaking of the glass,or else all to run out: at the end of 3 days let the water be gently evaporated away, and in the bot¬tom
tome will be found a moft noble Crocus Martis for the most stupendious tinctures of glasses, which keep for use.
To Calcine Brass called Orpello or Tremolante, which in glass makes a skie colour, and sea green. CHAP. XX.
Rass ( as it is well known ) is Copper, which by Lapis Calaminaris becomes of the colour of gold, the which Lapis Cala-minaris, doth not only colour the Copper, but also incorporating with it increaseth much it's weight; the which augmenta¬tion gives a colour to glass, when it is well Calcined, which is a thing very delightful to see, keeping the medium between a Sea- green and a skie-colour, when the Skie is clear and serene, wherefore be diligent in well Calcining it; to make it punctually, this is the way.
Take Brass, and to save charges, buy that which is in works, and Festoons, cut it in small pieces with a pair of Scisers, then D 2 put 36 The first Book. put it into a Chrysible covered and luted at the top in coals on a strong fire. I put it in the burning coals of the furnace where they are stirred, there let it then stand four days in a great, but not in a melting fire, for if it be melted, all the labour is lost, in that time it will be well Calcined, pow¬der it into a most subtil powder, and serce it, and grind it fine upon a porphyrie stone and there will come forth a black powder, which spread on tiles, and keep it on the burning coals in the leer, near to the round hole, four days, take from it the ashes that fall upon it, powder, serce, and keep it for use. The sign that it is well Calcined is, that if it be put into glass it makes it swell, and when it makes not the glass arise and boil well, it is a sign, either that it is not well Calcined , or that it is too much burnt, in which two cases, it makes .not the glass boil, neither doth it colour well.
To Calcine the said Brass, after an¬other manner, to make a transpa¬rent red , a yellow , and Calci- dony.
CHAP . XXI.
T Ake Brass and cut it small with sheers, and put it in a melting pot, make a S S S. with powdered Brimstone,and set it on kindled coals, put it in the burning coals of the furnace to Calcine for 24 hours, then powder, serce, and put it covered upon tiles of earth into the furnace, for 12 days, to reverberate, then grind, powder, and keep it for use.
Sea-green in glass, a principal colour in the Art.
Ea-green is one of the principal co¬lours given to glass, and if you would have it fair, and to hold at all trials, you must always make it in glass called Arti¬ficial Crystal; for in ordinary metall it ari-seth not fair : and though in Crystalline it ariseth fairer than in common glass, yet in the said Crystal, onely in perfection. Ob¬serve, that when ever you would make this colour, you in no wise add any Manganese at first, because this being added (although the fire afterwards consumes it,) yet it leaves a quality in the glass, which makes
the colour black, and gives it great imper¬fection and foulness. Now to make a fair Sea-green, take of Crystal Fritt, and put it in a pot, not allowing it any Manganese at all, and as soon as it is melted and clear, it yields a salt which swims at the top like oyl, let this be taken off with Iron ladles, by by the Conciators, take it out with much diligence, for what remains thereof, will make a foul, and oyly colour,and when the glass is well and perfectly clarified , take a pot of about twenty pound of Crystal, six ounces of Brass prepared as is aforesaid, and to this Brass calcin'd, add a fourth part of Zaffer prepared, and let these two pow¬ders be well mixed, and put to the said Crystal at three times, but at first this powder will make the metall swell very much, and you must well mix the glass with the long squares. Then let the metall settle, that the colour may be incorporated for three hours, then mix them again with the long square, then take a proof thereof, in doing whereof, put in rather too little than too much, for the colours may be ea¬sily heightned, which is to be done accord¬
ing to the works for which it is to be em-ployed, for gross tubes for counting houses require not so deep and full a colour, and tubes to make beads of, must not have too light a colour. At the beginning of twen¬
ty four hours (after it hath had the due colour) it may be wrought, and before you work it, mix well the metall from the ve¬
ry bottom of the pot, that the colour may D 4 be be well united , mixed, and spread tho- row all the metall, otherwise it settles to the bottom, and the metall at the top be¬comes clear. This manner of making Sea- green, I have tried at Florence in the year
1602 and made pots for tubes for count¬ing houses, always of a most fair colour. At Moran for the said tubes, they take half Crystall Fritt, and half Rochetta Fritt, from whence notwithstanding proceeds a fair Sea-green, although in Crystall alone it a¬
xiseth most fair.
Skie Colour or Sea-green.
CHAP . XXIII.
Et in the furnace a pot of pure metall of Fritt from Rochetta, or Barillia of Spain. The Rochetta of the Levant does best. As soon as the metall is well purified, then take to a pot of 20 pound six ounces of Brass calcin'd of it's self, as in 20 Chap, put it into the metall as is said in the Skie- colour in every particular ; observing that thism etail be skummed very diligently with with a ladle. At the end of two hours the metall must be very well remixed; take thereof a proof, and leave it so 24 hours, then it is mixed, and wrought, and this will be a most fair and marvellous Skie-colour varied with other colours, which are made in the art of glass. This colour tinged ma¬ny pots in Pisa in the year 1602 and there came out a fair colour bearing all proofs.
A Red colour from Brass for many colours.
CHAP . XXIV.
T Ake Brass in small plates, and put them on the arches of the furnace, leave them there closed until they are well Calcined of themselves with a simple fire, but not to melt. As scon as it is Calcin'd & powder'd it will become a red powder, for many, and those all necessary uses in the art of glass.
Brass thrice Calcine a to colour
CHAP . XXV.
ut the said Brass into the Fornello, or on the Lere of the furnace neer to the occhio, into earthen tiles or pans baked, Calcine it four days together, and it will become a black powder, and stick toge¬ther, powder it again, serce it fine, and Re¬
calcine it as before four or five days, for then it will not stick together, nor become so black, but russet, and powders of it self, wherewith is made a Sea-green , and Emeral'd-green, the Arabian colour called Turcois, a very beautiful Skie colour, with many other. Wherefore observe that it be not too much nor too little Calcined at the third Calcination, for in this cafe it co¬lours not the glass well, & the sign, that it is done perfectly is, that being put upon purifi¬
ed metal it makes it swell & boil suddainly, and when it doth not so it is not good nor well Calcin'd.
A Sea-green in Artificial Crystal. CHAP . XXVI.
T 0 a pot of Crystal Fritt containing 40 pound not charged with any Manga¬
nese, but well scummed, For when yo would make a Sea-green, never cast the Crystal into water, but onely scum it care¬fully , when this Fritt is melted and well purified, take 12 ounces of thrice Calcin'd brass, and therewith mix half an ounce of Zaffer prepared, unite these two powders well together, and put this mixture into the pot at four times, for so the glass receiveth it better. Mix the glass and powder with diligence, let them stand two hours, then remix them & take a proof, & if the colour be full enough, let them stand; And al¬though the Sea-green appears too full, yet the salt which is in the glass will cat up and consume the said greeness, and will always incline it to a blewishness. And at the be¬ginning of 24 hours it may be wrought.
I have many times experimented this way/way of making Sea-green without ever er¬ring. And if a moytie of Rochetta first be mixed with Crystal Frit, there will arise a fair Sea-green, and in Crystal alone 'tis marvellous fair.
General observations for all colours.
T Hat the colours may arise in full beauty and perfection, observe that every pot great or small, that is new, and put the first time into the furnace , leaves a foulness in glass from it's terrestriety,so that all the co¬lours that are made in them appear bad and foul ; wherefore those pots that are very great may be glased with white melted glass, as the Conciators well know, but the second time the pots lose this foulness. Observe secondly, that those pots which serve for one colour must not be used for another, for example, a pot which hath
been used for yellow, is not good to make a grain colour, and that which makes a grain/grain-colour is not good to make a green- colour , and that which serves for a red is nor good to make a blew, and so of all other colours. Therefore every colour must have it's own pot, for in this manner the colours will become more perfect. Thirdly, that the powders be well Cal¬cin'd ( that is) neither too much, nor too little ; for in either of these cases they do not colour well. Fourthly, that a due pro¬portion, and dose be used , and the mix¬ture be made in proportion , and the fur¬
naces be hot, and fed with dry and hard wood. Fiftly, that the colour must be used dividedly, to wit, one part in the Fritt, and the other in the metall, when it is melted and purified. There are other observations also which shall be treated of in their places, when we treat particularly of colours.
To/To make Copper thrice Calcin'd with more ease and less charge than the former.
TAke the Scales which trie Brafiers make when they hammer pans, ket¬tles, or other works of brass, which being often put into the fire the workmen ham¬
mer them , and these scales fall off, which cost much less than solid brass, wherewith is made the stuff hereafter described. And to Calcine it, you need not open and shut again the arches of the furnace (as in the aforementioned way) a thing of much dis¬advantage and disturbance to the furnace. Take then those scales that are clean, and free from all earth and foulness, wash them with warm water many times from their filth and uncleaness, and then let them be put into pots and pans of baked earth, and be kept in the leer near the Occhio, or in furnaces made for this purpose. I made at Pisa a little furnace in the fashion of a little Calcat Calcar, where were calcin'd 20 or 25 pound of these scales in few hours. Now let them stand in the said place four days, then renew them, powder and serce them fine, then again put them in the pans and pots of earth as before, with the same fire and heat as aforesaid for four days more, and they will come into a black powder, and run into lumps, beat, and serce those lumps fine, and repeat this process again, and a third time, then the scales will be prepared with much less charge than the former, and will thorowly have the same effect as the former; these scales rise much, wherefore use the prescribed care.
A fair Sea-green in Crystal metall, with the above-said sales.
CHAP . XXIX.
T Ake a pot of sixty pound of Crystal Frittwell scummed, and not cast into water. I made a Sea-green without wet¬ting the Crystall metall, and thought that it came out better. But we may make tryal of/of both ways, and stick to the best. Then take of metall well purified the said 60 pound, and one pound and a half of the said seales made with less charges, four ounces of Zaffer prepared, mix well these two powders together, put them to the Crystall at four times, mixing well the powder with the metall for two hours, than put it again to be well remixed as 'tis usual, and take a proof. Herewith I have made many times a most fair Sea-green with happy success. Mix half Crystall with Rochetta, and you shall have a Sea- green every way beautiful.
A Sea-green of lesser charge.
CHAP . XXX.
T Ake the same Brass prepared (as before ) with the same quantity of Zaffer, put them in the same manner and form to the Rochetta of the Levant, and also to that of Spain, neither of which hath had any Manganese, and which hath been well skummed, and not passed thorow water, using The first Book. 49 sing the rules as abovesaid in Crystal; for by this means it will receive a very fair Blew for all sorts of works, and will cost much less than Crystall: for the Rochetta is of much less value than the Crystall, as it is known. In this manner have I often made it at Pisa, and always with good suc¬cess.
A marvellous Sea-green, above all Sea-greens, of my invention.
CHAP . XXXI.
Et the Caput mortuum of the spirit ofV i¬L trial of Venus Chymically made without corrosives stand in the air some few days ; draw from it of it self without any artifice a green pale colour, this material being pulverised with the addition of Zaffer pre¬pared, and with the same porportion ( as is said in the other prepared Brass) the metall being added (as in the other Sea-green ) it will make a Sea-green, so fair and marvellous, that 'twill seem a very strange thing : I have often made it at E Antwerp/Antwerp to the wonder of all the specta- rors that saw it. The manner of making Vitriol of Venus, without corrosives, Spa- girically, is to take little thin pieces of Brass of the bigness of half a Florentine, and to have one or more pots ( as it is needful) and in the bottom of them to put a layer of common Brimstone powdr'd, and above it little pieces of the brass a¬foresaid , and than a layer of Brimstone, and after that pieces of Brass, work in this manner till all the Brass that you have be set to work, this being done, let the Brass be baked as followeth in the 140 Chap. then prove it,and to your content you may lee a thing of astonishment. I know not whether any have tried this way , which I have found wonderful, wherefore I say 'tis my own invention.
A green Emerald colour in glass.
CHAP . XXXII.
IN making Green you must observe that the metall have not much salt, with me-
tall that hath much salt as Crystall and Ro- chetta have, you cannot make a fair Green, but onely a Sea-green, for the salt consumes the Green, and always inclines the colour to a Blew. Wherefore when you would make a fair Green put common metall made with Polverine, into small or great pots, and in no wise have any Manganese. When it is melted and well purified, add to this metall a little Crocus Martis cal¬cin'd with vineger , about three ounces thereof to a hundred weight , let the me¬tall be well mixed, and remain so an hour until the glass incorporate the same tin¬cture of the metall Crocus, wch will make t glass come out Yellowish, and takes away the foulness and Blewness, which the me¬tall always hath. This process will give the metall a fair Green. Put of thrice cal¬E 2 cin' cin’d Brafs, made with (tales f as before ) two pound to every hundred pound of metall, and this muft be added at fix times, mixing well the powder, with the metall, then let them fettle two honrs, and the metall incorporate with it, then mix again the metall, and take a proof, and if the Green enclines to a Blew,add alitile more Crocus Mart is, io you fhall have a very fair Sea-green, called Leek green, which at the end of twenty four hours may be wrought: This Green I have many times made at Pifa, which came forth fufneiently fair. And (o it will to every one that fhaJI obferve pun&ually what is abovefaid.
y/ Green fairer than the former.
Ut if you would have a Green much fairer and fhining than the former, put into a pot of Crylfallinc which hath not had any Manganefe, and which hath palled thorow water once or twice, till all the faltncfs be gotten out, and to this Crv-
Crystalline, let half of common white metall made of Polverine be put in at se¬veral times, as soon as this metall is well mixed and purified, take to every hun¬dred pound, two pound and a half of thrice Calcin'd brass, made with plates of Brass in the arches of the furnace , and with this mix two ounces of Crocus Mar- tis Calcin'd with Brimstone, and reverbe¬rated, put these two powders well mix¬
ed together to the abovesaid metall, using the rules as before in the said Green, if the metall hath any Blewness give it a little of the said Crocus Martis,which takes it away, and then work it as the other Greens, and there shall be made the wonderfull Green of the Burnet. I have thus made it ma¬ny times at Pisa with very good success, for works more exact than ordinary. If you will have a fair colour, see that the Brass be well prepared.
A marvellous Green.
T Ake Brass thrice calcin'd as before, T then in stead of Crocus Martis, take the scales of iron which fall from the Smiths anvils, powder them finely, sift them clean from the coals and ashes, and with the quantity aforesaid, mix them well with the Brass, and put them to the common glass metall of Polverine , without any Manganese, with the rules aforesaid in the Green, and with this Crocus Martis, or scales, you shall doubtless have a more marvellous Emerald Green-colour, which will have wholly lost it's Azure and Sea-colour, and
will be a Yellowish green, after the Eme¬rald, and will have a shining and fairer lustre than the aforesaid Greens. The put¬ting in of scalcs of iron was my own inven¬tion. In the rest of the work let the rules and doses as in other Greens be observed,
and you shall have a strange thing, as expe¬rience hath often shown me.
Another Green,which carries the Palm
from all other Greens, made by me.
T O a pot of 10 pound of metall to wit half of Crystalline passed thorow wa¬
ter several times, and half of common white metall of Polverine, take four pound of the common Frit of Polverine, where¬
with mix three pound of red Lead, unite them well together, and put them into the same pot, and in few hours all of them will be well purified, then cast all this me¬tall into water, and take out the Lead, then return the metal which hath passed thorow the water into the pot, & let the metall pu¬
rifie for aday,then if you put in the colour made Chymically with the powder of the Caput mortuum of the Spirit of Vitriollum ve¬
neris, adding a very little Crocus Martis,there will arise a marvellous Green, fairer than ever I made any, which will seem to be a very Emerald of the ancient Oriental rock.
A Blew or Turcois,a principal colour in this art.
Ut sea salt which is called black or gross salt (for the ordinary white salt which is made at Volterra is not good) into the Calcar or Fornello till all the moisture be evaporated, and it becomes white, then pound it well,to a small white powder. This
salt so calcin'd, keep to make a Blew or Tur- cois colour. Put into a small or great pot of Crystal metall died with the colour of Sea- green ( made, as hath been said many ways.) But let the colour be fair and full (for this is of great importance to make a fair Skie colour ) according as you would have the Sea-green fair and excellent. To this metall so coloured, put of the said salt calcin'd into the pots, mixing it well with the metall, and this is to be put in by little and little until the Sea-green lose it's transparencie, and diaphanietie, and takes opacity,for the salt being vitrified makes the metall lose it's transparencie, and gives it a little paleness, and so by little and little makes the said Skie colour, which is the colour of a Turcois-stone;when the colour is enough it must be wrought speedily, for the salt will be lost and evaporated, and the metall returns again to be transparent and foul-coloured. But when the colour is lost in working add new burnt salt ( as be¬fore) that the colour may be reduced, and so you shall have your desired colour. Let. the Conciators well observe that this salt always crakcles when it is not well calci¬
ned, therefore let him have a care of his eyes and sight, for it endangers them. The quantity of salt must be put in by little and little, leaving some distance between each time , till he see the desired colour. But in this I used neither dose nor weight, but my eye onely. I have often made this colour, for it is very necessary in counting houses, and the most prised and esteemed colour that is in the art. Wherefore to make a Blew for counting houses, take the the Green of Crystal metall, and half Sea-green made of half Rochetta, which will become a fair colour, although it be not all Crystall metall.
End of the first book
The second Book, wherein are shown the true ways of making Calcidony of the colour of Agats, & oriental Jaspers, with the way to prepare all colours for this purpose, and also to make Aqua-fortis, and Aqua Regis necessary in this business.
And the Manner of calcining Tartar, and uni- tingit with Rosichiero, made Chap. 128. which produceth pleasant toyes of many colours with undulations in them, and gives it an opacity such as the Natural and Oriental stones have.
Since I am to shew the manner how to make Calcidonies, Jaspers and Oriental Agats, it is necessary first to teach the preparation of some mineral things ; for such compositions, and although some of them may be publiquely bought, yet not-withstanding, I being desirous that the work should be perfect judged it pertinent to my purpose to shew the most exquisite Chymical way, that the skilful may make every thing of themselves, both more perfect and with lesser charge. For there is no doubt that when the materials are well prepared, and the colour of the metals is well opened, and separated from their impurity and terrestriety which usually hinders the ingress of their tincture into glass, and their union in their smallest parts, that then they colour the glass with lively, shining and fair colours, which very far surpass those that are vulgarly, and usually made in the furnace. And because the colour of Calcidony , or rather it's compound (which is nothing else, but as it were a reuniting of all the colours, and
toyes that may be made in glass, a thing not common nor known to all) if they be not well prepared, and subtilised as is ne¬cessary, they give not the beauty and splendor to glass as is required. Wherefore it is necessary that the metalls be well calcined, fubtilifed, and opened with the beft Aqua-fortis, Sulphurs, Titriols , fal Armoniak, and the like materials * which in length of time, and at a gentle heat, are opened and well prepared, but a violent fire herein hurteth much. Tartar and Rofichiero ( be- fides their being very perfeft and well calcined ) muft be alfo put in proportion and in fit and due time, and you muft alfo obferve that the metall be well boiled, pu-rified, and perfected, and in working of it fome fuch care is to be ufed, as the diligent mafters are wont to ufe, and by thus doing the true fafper and Agat, and Oriental Calcidonies, with the faireft and bcauti- fulleft fpots of wavings, and toyes, with divers lively and bright colours. Hence it truly appears that nature cannot arrive fo high in great pieces, and although it is faid and may be made to appear true, that Art cannot attain to Nature, yet experience in many things fhows , and in particular in this art of the colours in glafs, that art doth ‘ not onely attain to and equal nature, but very fair furpaftes and excells it. If this were not feen, hardly would you believe the beauty, the toyes and wavings of divers colours, varioully disjoyned one from the other /other with a pleafing diftinction , which is feen in this particular of the Calcedony. When the medicine is well prepared, and the glafs wrought at a due time, the effect that cometh thence pafteth all imagination and conceit of man. In the three ways to make it, which I teach, I believe you may fee how far the art of glafs arifeth in this particular, where I demon-ftrate every particular fo diftinctly, that any pracitioner, and skilful perlfn, may underftand and work without errour, and he that works well may find out more than I fet down.
How to make call’d parting water, which dissolves silver and quick-silver, with a secret way
Take of Salt-peter refined one part, of Roch-alum three parts; but fifft exhale in pans all the humidity from it; to every pound of this stuff add an ounce of Crystalline Arfnick (this is a secret and no ordinary thing) which besides it's giving more strength to the water, helps to extract, better the spirits from the materials, which are the true nerves and strength of the Aqua-fortis, without which the water perhaps would be no better than well-water. Powder and mix them well together, adding thereunto the tenth pare in the whole of Lime, well powdred, mix-them well, and put so much of this stuff into glass bodies, that about three quarters of them may be full, let them be luted with strong lute, which I remit to the Artist as a common thing: but one not vulgar I will declare. Take some lime for example of the river Arnus (which is a fat earth known to all) one part, of sand 3 parts, of common wood-ashes well fisted, of shearings of woollen cloath, of each one half; mix them well together, and incorporate them into a past with common water, work them well together, for the more 'tis wrought the better 'tis, therefore see that your past be a little hard, to all these add a third of common salt, which incorporate well with the lute, 'tis a business of impor¬tance, tance, then-lute the glafics with this perfect lute, and fee them in wind furnaces, fitting to their bottoms, baked earth which will bear the fire. Under the bottom of thefe bodies, let there be four fingers of find, & thick Iron bars to bear the weight, & fill’d round about with fand , put receivers of glafs to them, large and capacious within, lute the joynts well with lute made of fine llowre and lime, of each a like quantity, powdred, mixed, tempered, and imparted with the whites of Eggs well beaten, with this lute, binde and lute the joynts with roulers of fine linnen, which , when well dryed and rould about three or four times, make a very ftrong lute, rouling but once at a time, and letting it dry a little before the fecond rouling. And then this will bear all the violence, fury, and force of the fpiritsof the Aqua-fortis, and to this end fit exactly a very large receiver to every glafs body. And when they are well dryed make a fire in the furnace onely with coal at firft, and that a very temperate one, for three hours, for in that time the windy moirture ‘diftilleth off ’, which endangers the breaking of the glaffes, and continue for fix hours a moderate fire , afterwards encreafe encreafe it gently, adding billets of dry oaken wood to die coals, and fo proceed by little and little, augmenting it for fix hours more, and then the head will be tinged with Yellow, a fign that the fpirits be¬gin to rife; continue this degree of fire un¬till the fpirits beginning to condenfate colour Red the receiver and head, which will always grow deeper colour’d like a Rubic. Then encreafe the fire for many hours, till the head and receiver become Red [increase the fire until the head becomes red, RB], which fometimes lafteth two whole days. Continue the fire by all means till all the fpirits of Aquafortis be d if til I’d off, which is known, when the head & receivers by little and little, begin to grow clear, and become white as at firft, and wholly cold ; yet notwithftanding continue the fire one hour more. Then let the furnace cool of it’s felf. Obferve, that when the head and re¬ceivers are Red , and the fire ftrong, you admit no wind, nor cold air into them, nor touch them with any cold thing, for then they will eafily crack, and your pains, coft and time will be loft, wherefore when they are in this ftate , let them be kept hot in the fire. Now, when all is cold, put ups on the head and receiver linnen cloaths F wetted.
wetted and well foaked in cold water, that the fpirits which are about the bead and receiver may the better fink intó the Aqua¬fortis., leave them thus for 12 hours, then bath the joynts and lutings with warm water, till they being moiftned you may take off the bandage, and the head from the receiver, which ufually are fafe. The bodies may be broke and thrown away, for they will ferve no more, powder the dregs and refidences of the Aqua-fortis* to wit, about their third part, and to every pound of them add four ounces of Salt-peter refined, and put them into another body luted, and pour on them the faid Aqua-fortis* lute and diftil them as before in everything. Keep the Aqua-fortis in earthen jugs well ftopt that the better fpirits may not evaporate. This parting water is good for the following ufes. Some there are that inftead of Roch Alume take as much more of the beft Vitriol, fuch as the Rowan or thé like is. The fign that Vitriol is good for this ufe, is, that being rub’d upon polifhed Iron it colours it with a Copper colour. This Vitriol purified after the following manner, will make a ftronger Aqua-fortis than Alume.
To yurt fie Vitriol to make the Jtrour- efi Aqua-fortis.
Moke the bed Vitriol (the better, the ftronger the aqua-fortis) in common warm water , let the folution ftand three days being impregnated with falt, then filtre and evaporate in glafs bodies two thirds of the water, and put the remainder into earthen pans glafed, which fet in a cold place, in 12 hours the Vitriol will fhoot into pointed pieces, appearing like natural Ctyftallof a fair Emerald colour. Dilfolve this fame Vitriol again and do as before, and repeat it thrice, at each folution there will remain at the bottom of the glafs a Yellow fubftance, which is it’s unprofitable Sulphur, and is to be caft away. At the third time the Vitriol will be purified, and fit to make a good and ftrong aqua-fortis^ much ftronger than the ordinary, cfpecially if the Nitre be well refined.
How to make Aqua Regis.
CHAP . XL.
To every pound of the said Aqua-fortis, put two ounces of sal Armoniack powdered, into a glass body, which set in a pan full of warm water, and let the Aqua¬fortis be often stirred, wch will soon (which will soon) dissolve the sal Armoniack with it's heat,wch will be (which will be) tinged with a Yellow colour, put in more, sal Armoniack, as long as the Aqua-fortis will dissolve any, when it dissolves no more let it settle a little, when it is clear decant it leasurely off, and in the bottom there remains the unprofitable terrestriety of the sal Armoniack. Now this, Aqua Regis is strong and fit to dissolve Gold, and other metalls; but silver it toucheth not at all.
To burn Tartar.
CHAP , X L I.
Ut Tartar of Red-wine which is in great pieces, and appears full of spots (lay by that which is in powder, for it is not good) into new earthen pots, and let it burn in kindled coals until it smoaks no more, and when it is calcin'd, and in lumps of a black purplish sustance then it is burned and prepared.
How to make a Calcidony in Glafs
Put of Aqua-fortis* two pound, into a glafs body not very great, but with a long neck, four ounces of fine filver, in fmall and thin pieces, and fet them near the fire, or in warm water, which as foon as the Aqua-fortis begins to be hot ’twill work and diffolve the filver very quickly, and continue fo until it hath diffolved, and taken it up, then take a pound and a half of Aqua-fortis* and in it diffolve ( as you have before done with filver) fix ounces of Quick-filver* when all is dilfolved let thefe two waters be well mixed in a greater body , and powr upon them fix ounces of fal Armoniack* and diffolve it at a gentle hear, when it is diffolved put into the glafs one ounce of Zafier * and half an ounce of Miwanefe, each prepared, and half an ounce of Feretto of Spain [Feretta] * a quarter of an ounce of Crocus At art is calcin'd with Brimftone., thrice calcin’d Copper, Blew fmalts of the Painters, and Red-lead, of each half an ounce, powder all t’nefe well, and put one after another into the body, which then ftir gently that the Aquafortis may be incorporated well with the faid powder, keep the body clofe Roped for ten days, every day ftirring it well fevcral times, and when they are well opened, then put it into a furnace on fand, and make a moft temperate heat, fo that in 24 hours all the Aquafortis may be evaporated. Obferve that at laft you give not a ftrong but a gentle heat, that the fpirits of the Aqua¬fortis may not evaporate, and in the bottom e there will remain a Lion colour, which being well powdered , keep in a glafs veffel. When you would make a calcidony, put into a pot very clear metall and made of broken pieces of Cryftall veftels, and Cryftalline, and white glafs . which hath been ufed. For with the Virgin Britt which hath never been wrought, the Calcidony can never be made, and the colours ftick not to it, but are con-fumed by the Britt. To every pot of a- bout 20 pound of glafs, puc two ounces, or two ounces and a half, or three ounces of this powder, or medicine, at three times, and incorporate, and mix them, that the glass may take in the powder, in doing whereof it raiseth certain Blew fumes, as soon as it is well mixed let the glass stand an hour, then put in another mixture, and so let it alone 24 hours, then let the glass be well mixed, and take there of an essay, which will have a Yellowish Azure colour, this proof being returned many times into the furnace, and taken when it begins to grow cold, will shew some waves, and divers colours very fair.
Then take Tartar eight ounces, soot of the Chimny well vitrified two ounces, Crocus Martis calcin'd with Brimstone half an ounce, put by little and little all these well powdered and mixed into this glass at six times, expecting a little while at each time, still mixing the glass that the powder may be well incorporated. As soon as all the powder is put in, let the glass boil, and settle 24 hours at least, then make a little glass body of it, which put in the furnace many times, and see if the glass be enough, and if there be on the outside toyes of Blew, and Sea-green, Red, Yel¬low, and all colours with toys, and it hath /hath fome waves 3fuch as Calcidony* Jafpers, Oriental rigats have, and that the body kept within be as to the fight as red as fire. Now as foon as it is made and perfeded it is wrought into veffels always variegated, which are not to be remade, for they do not arife well. Thefe veflels may be made of divers forts, and drinking glafles of many fafhions , broad drinking cups, falts, flower pots, and the like toyes, ftill obferving that the matter workman pinch off well ye glafs (that is wrought) with pincers, and anneal it fufficiently, that it may nuke waves and toyes of the faireft colours. You may alfo make with this pot difhes, pretty large in Oval, triangular* quadrangular form, as you will, and after¬wards work it ac the wheel ( as jewels ) for it rakes polifhing, and a fine luftre, and it may ferve for little tables, and cabinets ; fo that thofc little Jewels will reprefent the Oriental Agat* Jofper, and Oriental Calcidony, and when it happens that the colour tadeth, and the glafs becomes tran fparent, and no more Opacous as it ought to be for thefe works, then ceafe from working,put to it new Tartar calcin’d, foot and Crocus ,for thus (as before) it takes a body and Opacoufnefs, and makes the colours appear; fet ic then to purine many hours, that the new powder put in may be incoporated, as’tis ufual, then work it. This was my way to make Calcidony in the year 1661 in Florence, at Cafino in the glafs furnaces; at which time I caufed to work in the furnace, the brave Gentleman Nicolao Landiamo my familiar friend, and a man rare in working Enamels at the lamp, in which furnace I made many cups of Calcidony at the fame time, which always were fair to all eflays, never departing from the a-forefaid rules, and having the materials well prepared.