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. XXVIII. How Black or white Silver is to be burnt clean, and how the Tests for it are to be made right.

[Section. 1] SILVER-burning is to burn Silver pure and clean and deft upon a Test, and this * 1.1is to be done to the Blink Silver (which is not yet clean enough) by two ways; one way under the wood, before the Bellows) the other under the Muffle, and is only done with Coales.

But I intend to write first of the Tests in which the Silver is to be burnt clean; they are to be made and [ 2:] * 1.2prepared thus, Take Ashes from which Lees hath been made, which are not sharp or salt: wash them and let them be dry, and keep them for your use, and when you do intend to make a Test, first get an earthen unglazed test such as the Potters use to make in their frames, and so large as thou wouldst have them, pour water in it, and make it wet all over, that the Ashes may stick the better, then put some Ashes into it, which must first be moistned like unto the Copel-Ashes, put it two fingers high in the Test, press it together with a woo∣den Pestel, which hath about eight Angles: then put more Ashes after it, press them also down, do it so long till the Test be full, then stroke off the superfluous Ashes with an Iron made on purpose from the test, and turn it about the Brim (with a round wooden Ball) so as the Ashes may lye smooth doon upon the test, after∣wards cut it, with a round sharp bent Iron, according to the bigness of the Silver that is to be burnt upon it, and when the test is cut out, then must you have a small hair

Seeve, and put ground Bone-Ashes in it, and swigle or strew it over the test, that it may be white all over, and then turn the Ball over it, that it may lye smooth upon the test, so is the test ready.

[ 3:] * 1.3When you intend to use such test, and to burn in it, then first make a Small-coal fire upon it, that it may be dry, then set it before the Bellows very even, so that the Bellows may blow just into it, which is to be known thus, hold a shovel over the test, and if the blowing of the Bellows do go off from the shovel and blows off all the Ashes and dust out of the test, it doth stand right, and then beat the piece of Blink-silver into bits, but first put a little straw into the test, and the bits of silver up∣on it; Give it fire and coals that the test and the silver may be well covered, then begin to blow, so the silver will melt easily, and begin to drive, then put away with an iron-hook all the Coals from the silver, and stroak the silver also clean off, yet so that nothing may be lost, then lay split wood, or other wood for fire, and fit for the purpose, and cause the Bellows to blow under [Section. 4] * 1.4the Wood upon the silver, so the silver will begin to drive under the wood, and that lead which did remain among the silver will be drawn into the test: only con∣sider▪ when such split wood is burnt upon the test, then put more wood by or upon it, that still the silver may be burnt with a fresh flame, and so will it be sooner clean, while the silver doth yet go upon the test, and it must be stirred about with a round bowed Iron-hook, and made glowing hot, whereby the silver may be clean, or else it will retain some lead underneath.

[Section. 5] * 1.5But that the Silver may not be Burnt so much, but may have a right and true content, namely, fifteen loth, and three drams, (which commonly the burnt Silver is to have) then you may in the mean time once or twice, with a well pointed Iron, (thrust a little into the Silver)

and take a proof out (which will hang easily about it) then beat it off, and see if it hath much yellow Litharge, or beat it upon an Anvile, and if it be Deft, then the Silver is well burned, if not put the proof in again, and let the Silver drive longer upon the Test, until you do find the proof upon the Iron, white and deft, but the Silver upon the Test cannot be overdone, because the Test grows soft from superfluous heat, and take more Silver to it than it ought; all which is well to be observed, and di∣ligent exercitation or use is needful, if one will burn blinck Silver upon a certain content.

[Section. 6] * 1.6And if by negligence, the Silver (before it is done) doth become cool, put again Coals upon it, begin it a∣gain and burn it that it may be right, for the hard burnt Silver do (in Coyning) hurt: of which afterwards a great dammage will follow.

[Section. 7] * 1.7Some of the Refiners in the burning of Silver do put upon every Mark of Silver a half Loth or Dram of good Copper that the Silver may not come too high, but upon their just content, not that it remaineth with the Silver, but because it goes together with the Lead in the Test, that the same burnt Silver (as we have heard) may not become of such a high content; this is a good intention in such places, where the Silver for Payment up∣on a certain content are given in, and, without proving, accepted, and there reasonable dilligence in burning may be so observed, that none of the parts may be wronged and hurt.

[Section. 8] * 1.8Whole Coppery blinck Silvers, such as they make in the Refining Houses, may be burnt very Deft, but they will remain too light on the Content, to the same must be put a little Lead, (as much as it will permit) as some∣times likewise may be done to the Silvers which are mel∣ted of speizy and Cobolt Oars for their Wildness and uncleanness sake.

[Section. 9] Now when the Burning is finished, and the Silver ta∣ken out of the Test, then is it to be fully quenched, where∣by the Ashes will fall easily away, which stick about * 1.9it, and the rest of the Ashes must be taken away cleanly, with a strong Brush, and let the Silver be dry, and when the Thornels (if there be any) and the Silver hath ta∣ken hold on the Ashes, they must be beaten down with a Hammer, that the piece on all sides may be smooth.

But that the Reader may have a larger understanding of the Silver Burning, also how the France, and Test, with all other things appertaining to them, are to be formed, is clearly to be seen by the following Sculpture, which is thus

[illustration]

Deciphered.

• 1. The Burning Furnace.
• 2. The Test which is put into it.
• 3. How the Silver is burnt on the Test.
• 4. The Bellows blowing.
• 5. The Iron-plates Luted over with Clay and used against the heat.
• 6. A Fork and Hook to stir the Melted stuff or Me∣tals, as also for Iron-proofs.
• 7. An un-used or unwarmed Test.
• 8. A Test that is in warming.
• 9. A Roaster or Iron, on which the burnt Silver is made dry.
• 10. The Water-Tub over which the burnt Metals is brusht and cleansed.
• 11. The Ball and Pestle for making Tests.
• 12. The Block upon which Silver is beaten with an Hammer.
• 13. The split-wood for the Silver burning.
• 14. A Test that hath been used and Broken.
• ...

[illustration]

• 15. A three footed stool for several uses.
• 16. A Tankard to put Water, into Fig. 11.

Sculpture. IX.

Notes

• * 1.1

  Deft or neat
• * 1.2

  To prepare the Tests.
• * 1.3

  The manner of this Burn∣ing.
• * 1.4

  Wood for the burning of Silver.
• * 1.5

  The content of burnt Sil∣ver.
• * 1.6

  How the Silver doth cool.
• * 1.7

  Silvers that are not burnt too high.
• * 1.8

  Coppery Blinck Sil∣vers.
• * 1.9

  When the Silver bur∣ning is fi∣nished.