Fleta minor the laws of art and nature, in knowing, judging, assaying, fining, refining and inlarging the bodies of confin'd metals : in two parts : the first contains assays of Lazarus Erckern, chief prover, or assay-master general of the empire of Germany, in V. books, orinally written by him in the Teutonick language and now translated into English ; the second contains essays on metallick words, as a dictionary to many pleasing discourses, by Sir John Pettus ... ; illustrated with 44 sculptures.

CHAP. XX. How to separate Gold and Silver, and how to burn or distil Aqua fort. and prepare Instruments and Clay for the Work.

[Section. 1] HOW, in respect that to the Burning of A∣qua fort▪ there belong many Preparations, it is necessary that of such I write some∣what, and signify the same: Where∣fore, I will first speak of the Clay where∣with they use to Lute the Helms and Receivers, and to coat the Separating Glass which ought to be prepared thus; Take good sound and substantial Clay, wash it in water that the stones and the course sand may come off, make it into Balls, and dry it well in the Sun; Of such wash'd Clay take ten parts, and two parts of wash'd Ashes, three parts of clean Stone-Horse-dung, one part of the scales of Iron, and two parts of Cow-hair beaten well, and min∣gle all these together, and moisten it with warm Oxen or sheeps-blood, and whilst it is warm, work it with an iron Instrument: one might also take, among this Clay, Venetian Glass beaten small, but not too much: and with this Clay one may lute-over the separating Glasses and the great Glasses, in which the Aqua fort. is to be distilled, such as will hold in the fire: it may also serve to joyn together the Ovens which are called Athanors,

because it holdeth fast, and doth neither break nor crack.

[Section. 2] But the Clay and thin mixture with which one useth to lute over the Joynts of the Helmets and Receivers, is is to be made thus, Take the white of Eggs, as many as you think fit, beat them well, in a Peuter dish, and take a clean spunge, and press the clear of the Eggs into it, by squeesing it out of the spunge into the dish, and do this until it becometh clear like Well-water, then take Mill∣dust, 4 Loths, Bole Armoniak, one Loth, white dryed Cheese without Crust or rind, two Loths, and of Sanguis Draconis, one Loth; Grind all these very small, and sift them through a hair Seeve, mingle these with the whites of the Eggs, and with it, Lute over the Joynts, which you must understand thus, That such Joynings be first with the above-mentioned Clay luted over and dryed well again, then this thin mixture is to be put upon a little cloth and laid over it, and let it dry of it self, but this ought to be done before you bring it into the warmth, or makest a fire to it, then such mixture will hold fast, and the spirits will not go through, but if the Joynings should afterwards let the spirits go out, then do it over in the heat with Tallow, vvhereby the Clay will become hard and fast.

[Section. 3] Here followeth another Clay wherewith to lute or glaze-over the Culbs or bottles, which will endure the fire, Take a good wash'd dry Clay, a little Dragons blood and Bole Armoniak, and add to it a third part of Potters clay, & a third part of a half part of Calx vive, make each apart into Pouder, and moisten it with the white of Eggs, as is taught above, or with warm Ox or Sheeps-blood, add to it so much flox of woollen Cloth or wooll shav'd or shorn, as of the Bolus, mingle all well together with a stick or wand, and with it lute over the Glasses, but▪ not thick, also lute over the joynts with it, and this vvill

hold fast in the fire. Likevvise other Clays are to be used to lute-over, which do also hold well: But because these now mentioned do suffice, I have omitted for bre∣vity sake to set down others: therefore every one may try which are the most serviceable unto him.

[Section. 4] The Glasses or Bottles in which one useth to separate, and in which they put Aqua fort. are to be made of good Venetian Glass, of an equal thickness in the midst, for if they be made too strong or thick of Glass, they will not hold well, but they which have a right equal thickness, and are not strong will endure the fire the bet∣ter, but if the Glasses be made of other Glass, then the Aqua fort. will work on them, and they are subject to break the sooner, by which there cometh dammage, and they will be also dark and pale.

[Section. 5] One may also cause Juggs of Potters-work to be made for Distilling Aqua fort. or mixing Clay with Bran or clean fine Sawdust, this therefore is done, That when the Juggs are made and burnt raw, that the Bran or Saw-dust may burn out, and then to glaze such over with Venetian glass within and without, that the Glass flow into the holes, out of which the Bran and Sawdust is burnt away, whereby they will prove very firm and hold very well in the fire, of such stuff very good Re∣torts are made, which will not break in the fire, but are much better to use than the over-luted Glass bottles, therefore such stuff is very convenient to use for Retorts: But how great the Juggs, Glasses or Bottles must be, I conceive, that every ones Work will teach what he may make according to it, for if one hath much Aqua fort. to burn at once, then it will require a great Jug or Re∣tort for it, in which the stuff is to be put, and also the Recipient must be the bigger.

[Section. 6] Also 'tis in use to burn Aqua fort. in Iron Jugs which are of two pieces, and can be done asunder, whose form

you will see in the next Sculpture. In such a Jug one may set in more at one time than in a glass-bottle; also they need not fear the breaking of such Jugs, or that the stuff will be spoil'd in it; and the Gold hath been of a better colour by such Aqua fort. made in Iron.

For this and other Reasons, I judge it to be better alwayes to burn Aqua fort. in such Iron Jugs, than in glaz'd Bottles, which can but once be used, the bigness of which must be as one may put in near 20 pounds of stuff at once, but if one would burn less, the Opportu∣nity will shew it self, how to proportion it, but for strength it must be the thickness of a finger, so it will en∣dure the longer.

[Section. 7] If now one will burn Aqua fort. in such Jugs then must the joynings be well luted over, that no spirits may go out, lute-over also the Jug without, with thin Clay, that the fire may the less hurt it, and lay before it a Reci∣pient of Glass, but of such a bigness that the mentioned spirits may have room enough in it, and that such may not break out of necessity or force, by which there will be dammage.

[Section. 8] After the vvork is finished then must the Jug be suffe∣red to cool, and put water in it, then will it mollify the Caput Mort. put it out gently with an Iron, and so the Jug will become clean again.

The form and likeness of such separating Glasses and earthen Juggs you may see in the following Sculpture, thus

[illustration]

Deciphered.

• 1. A luted glass-bottle covered with an Helm.
• 2. A luted glass-bottle without an Helm.
• 3. Another sort of Glass-bottle.
• 4. The Form of an Helm.
• 5. An half Glass, or half Pipkin with one Ear, and a Mouth.

[illustration]

• 6. A Receiver with a Pipe.
• 7. A Receiver without a Pipe.
• 8. An earthen Retort.
• 9. An earthen Jug or Culb to burn Aqua fort.
• 10. Other kind of Bottles, Glasses, half-Glasses, Tunnels.

Sculpture XX.

Notes

• The Clay.
• To lute the joynings.
• Another Clay to bodies.
• Venetian Glass.
• To prepare Jugs and Retorts with saw∣dust.
• ☞
• Iron jugs.
• Luting the Jug.
• To gain the Caput. mort out of the Jug.
• Absuzchal