Marcasit dissolved in Aqua Regia, precipitated with the liquor of flints, edulcorated and dryed, whereof from one to five grains, to ℥ j. of the mass, give a Saphire, but not comparably so polite as one made with gold.
But being unwilling to calcine Marcasite, let him take Zafora, and mingle to ℥ j. from five to ten grains; Granates of Bohemia, or Oriental pulverised, add from six grains to ℈ j. to ʒ j. of the mass, for little green stones like to the natural smaragd or emrald: other things which remain of the mixture of the colours, are to be learned by experience.
To what uses coloured flints and crystals are appointed, is not here to be treated of; one use excepted, which I set down for the eyes, which are weakened by too much watching, the heat of fire and smoak; see thou have a waxen mold circularly round, of the bigness of a dish or trencher; (the Optiques are wont to call such lentes) to which, put the best clay well mixed with hair: anoint the waxen type with oyl, and exactly apply the best prepared earth of crucibles (and durable in the fire) the thickness of a finger; which being dryed, perforate in some part, that the wax being melted by the fire, may flow forth: afterward burn the mold in an earthen furnace; being burnt, fill it with prepared glass, and place it in a wind furnace till the glass melt; which at length being cooled, take off the type by attrition, and there shalt thou have the crystal resembling the form of the type; which afterward thou must make and polish like spectacles in an iron dish on both sides; and take it out with a strong iron wier, and thou shalt have a good crystalline lent for a small price, which otherwise is scarce made of crystal of so great a bigness. And if thou wilt, thou maist colour the glass green, very pleasant to the sight, and fit a foot to it for greater benefit. And the glass doth not only serve for the Multiplication of light in the night time, that you may see a thing a far off in a chamber, but also for the fixing and calcining minerals by the Sun-beams, and melting of Metals, and multiplying of Pictures, like an hollow glass, and also for other uses it may be compared with an hollow looking-glass, which doth the same of an equal bigness with the hollow glass; nor is there any other difference of them but reflexion. This glass-instrument is made likewise another way, and by less cost and labor, if it be of a polisht looking-glass, if two great orbes are cut out with a diamond, and if they are somewhat softned with Fire, and are left there so long in the heat, until they shall stick like wax very close to the stone, which done, let them be cooled again, which afterward taken out, will represent the form of an hollow glass; to which, it behoves to fix a leaf on the convex part. And the glasses do the same that an hollow metallick looking-glass doth, the reflexion excepted, which is not so strong as of the hollow glass: And although the glasses are sooner broke, yet they are very fit for the making of the following Instrument.
And they are bound together with a strong wier, applyed across on the concave part, and an hole is cut in the brim with a diamond on one side, of the bigness of a pea, then the crevises are exactly closed in every place with the best lute; which done, a silver or copper ring is to be tyed about it, holding those glasses straightly, so that the Instrument may be fitted to the foot, all which well done, those strong wiers are separated or cut off, with which the glasses were bound at first, namely, near the copper ring: afterward very pure Aqua vitæ is to be put in through a funnel, as much as is required for the filling it up; the Instrument being filled, the hole is shut up, which is to be kept for use; and this Instrument is better than the hollow glass; especially, if it have in its diameter the breadth of one foot, and may be applyed to prospective pictures, it doth excellently represent and multiply them.
Behind which, if you place a candle in the night, it gives so much light in the Chamber, that you would think it came from the Sun. It doth also many other things which are here omitted as superfluous. And you may gather the dispersed light in the aire in the night time with it, so that you may read the smallest writing. Such and others of the like things may be done by this furnace, all which to set down, would swell the Book too much. Other things of the metals examination and purification by fusion, in another place.
Take this, Reader, which is given to thee, in good part, at another time thou shalt have better; and do not mistake my writings, as if I did reprove the examinations of metals by the Ancients, fusions and separations, who only would communicate my opinion, and yield my assistance for further proceeding; for I know that dealers in metals giving too much credit to their small proof when they find nothing, do, contemn oars as barren, often abounding with gold and silver; when nevertheless, John Mathes. says expresly in his Sarepta, that minerals oftentimes tryed in a small quantity do yield no gold and silver, which in a great quantity, yield a great deal, wherefore credit it is not always to be given to such tryals, often deceiving, as experience testifies.
And this not only in those minerals which are digged out of the earth; but also in those clayie and sandy minerals, abounding with silver and golden flames; out of which neither by the less nor greater proofs, nor ablution nor Mercury is drawn with gain that thin and fiery dispersed gold: which by some waters is done without fire easily; for I know such mines are found neer many rivers of Germany, and many places in other Nations of Europe, out of which honest gain without much cost and labor may easily be gotten. Neither are they dreams, which I have spoken parabolically of the perfection of metals, for it is possible by art to help nature in the perfecting things. There is therefore no more need of any thing than of knowledge; therefore the nature of metals being known, and their properties, they are easily separated, purged and perfected.
But what I have written of the universal medicine, I have done for the aforesaid causes, which have made me believe the thing, not as professor of the Art. The other things of coloured red glasses and looking glasses I have added, because they are easily prepared by this furnace, as sometimes necessary in some works. Other things of the handling metals are not without cause now omitted, which happily may be sometime delivered in another place, wherefore now we end.
FINIS.
