Of counterfeiting precious Stones, t 8 l

strain them , and dry the rust, and set icagain to the fire, till it be red hist, thenquench ic again with vinegar ; this they do three or four times: at length they boilthe vinegar away, and take the remaining Crocus from the bottom, Nextremairisto lhew

How to reduce Zaphara into Powder.

A little window is to be made out of the side of the fornace, high to which mustbe built a little cell or oven, so joyned to the mouth of the oven, that the flame maybe brought in through a little hole. Let this cell have a little door without, to ad-mit the workmins hand upon occasion. Let this cell be afoot in length and breadth.Set the Saffron upon a Potters tile, into the cell, and (hut the door: let it be red hot,and after six hours take it out and put it into water, so will it cleave into pieces; letit be dryed,stamped, and lo finely icirced , that ir may scarce be felt. But if it can-not be effected with a pestle and morter ; pour water upon the powder, and stir icwith your hand?, and let it settle for a while; then strain it into another vessel, andpour frefti water into the powder; and reiterate this so often , till that which set-leth, beingbea: and brayed, do pass through with water: then dry it, and it willbecome very fine powder.

How to burn popper.

Set the filings of Copper, with an equil quantity of salt mixt in an earthen pot, overthe fire, and turn it about three or four hours with an iron hook , that it may beburned on all fides: There let it burn a whole natural day : then take it out, and di-vide it into two parts; lay the one part aside, and set the other with salt on the fireagain, for an artificial day: do the same three or four times, that it may be more per-fectly calcined, always having a care that it be as hot as may be, but that it melt not.When it is burnt, it is black.

Chap. V.

How Gems are coloured.

A LI things being thus prepared ; there is nothing more, I think, remaineth tomake an end of this work , but to know how to colour them, And we willbegin with the way

How to dye a Saphire.

Artificers begin with a Saphire: for when it is coloured , unless it be presently re-moved from the fire, it lofeth the tincture; and the longer it remains in the fire,the bright er it grow e th. Put a little Zaphara, as they call it, into a pot of glass,two drachms to a pound of glass; then stir it continually from top to bottom with aniron hook : when it is very well mixed, make tryal whether the colour please youor no, by taking a little cut of the pot. If it be too faint, adde some mote Za-phara ; if too deep, put in more glass, and let it boil six hours. Thus you may

Colour Cjanuiy

or sea-water, another kind of Saphire. Beat your calcined brass into very fine pow-der, that you may scarce feel it; for otherwise it will mix with the Crystal, andmake it courser: the quantity cannot be defined : for there are lighter and deeper ofthat kind: for the most part, for one pound one drachm will be sufficient.

How to counterfeit the colour of the Amethift;

To a pound of Crystal, put a dram of that they call Manganese , and so the colour ismade. If the Gem be great, make it the paler; if small, make it deeper: for they usesuch for rings, and other uses.

To counterfeit the Topa&e. .