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. XV. Twelve Directions how to separate Silver from Copper in the great Work.

[Section. 1] TO separate thus is a curious ART, which for many years the Refiners have kept as a great Secret, how the Precipitati∣ons are to be made right. But because the large Works are very great, there∣fore [Section. 2] * 1.1it could not remain secret, but is now known; yet there is still a difference, for in one Furnace it is better refined, and the prepared copper is made purer than in the other, also the Additions are not every where alike, and then many sorts of coppers can∣not be refined all in one way, therefore for their sakes, who either know nothing, or but a little of such things, I will write somewhat as a tendency to that Art.

[Section. 3] First, observe whether the black Copper be weak, deft, hard or brickle, for if they be weak and brickle before the refining, then the Silver will not come so soon out, but if one will give it its just due and heat, then the copper will flow under the lead through the Oven, and may cause hurt; therefore to the weak Coppers, there is no better way than to mingle other hard or brickle copper among it, that the one may hold the other.

[Section. 4] Secondly, one must be instructed how much the Cop∣per holds in Silver, by a diligent Proof, for according to it, the Copper must be mingled with lead. And if

the Contents be unequal as from 24 Loths, to 14, 8, or 10 Loths, then it must be made into a Cake by weight, near 27 pounds and an half of rich Copper, and 55 pound of poor Copper, upon this make your Account, how much Silver is in this 3 quarters of the Centners of Copper, and how much the Lead containeth which is to be used to the Addition, and then to every Loth of Silver which is in the copper and lead) 17 pound of [Section. 5] * 1.2lead is also to be counted; and thus, of the refined lead (which is to be parted from the copper) a Centner will not contain above six and a half, or at the highest seven Loths of Silver. But if the refined lead should contain more than 7 loths, it is a sign that the Cakes remain too rich, and that the silver is not all come forth of the cop∣per, and that there was not lead enough to the Addi∣tion.

[Section. 6] But, that one may know how 'tis with the Additions upon every Copper, and what is to be observed in the re∣fining Furnace, I shall demonstrate it by Examples.

[Section. 7] Take two Centners of lead, and three quarters of a * 1.3Centner of Copper (of a rich and poor Content) either weak, hard or brickle, one among another, if there∣in is not 12 or 12 and an half loths of Silver, then take lead Oar or other lead to it which is silvery, that you may have the above mentioned silver in the fresh piece, and then add Lead, or Littarge, as much that there may come to four pieces, 8 Centner of Lead, and three Centners of Copper, and of this there will come out in parting 6 Centners of refined lead; every Centner of which contains 6 Loths and a half of Silver, the other Silver and lead will remain in the cakes and lead, which will almost all come to profit again, as you will hear hereafter.

[Section. 8] Another Addition upon two and a quarter of a cent∣ner of Lead, viz. take three quarters of a centner of cop∣per,

and if there be not in it 15 or 16 loths of Silver, then take to it rich lead, which may enter in a fresh piece of such Silver: or, Take fresh and hard lead and Litarge, so that from 4 Pieces (upon an Oven) may come 9 cent∣ners of Lead, and 3 centners of copper, of this there will be 7 centners of refined Lead, of which a centner is to contain 6 loths and a half of Silver.

[Section. 9] Also, take two and three quarters of a centner of Lead, and three quarters of a centner of copper, and if there be not 18 or 19 loths of Silver, then take rich lead that it may reach the Silver and Litarge, and hard and fresh lead, so that (upon an Oven) in 4 fresh Pieces may come 11 centners of lead, and 3 centners of copper; and in di∣viding of this again, there will be 9 centners of fine lead, and one centner is to contain 6 loths and an half of Silver.

[Section. 10] Or take three Centners of Lead, and three quarters of a Centner of Copper, if there be not therein 20 or 21 loths of Silver, then take rich lead which came in a fresh Piece of the silver, viz. from 4 Pieces (in one Oven) 12 Centner of lead, and three Centner of Copper, and when this shall be separated, then 10 Centner of pure lead; and one Centner will contain seven loths of Silver in the Keinstocks and Thornells, and there will remain 15 or 16 loths of Silver, and they are further to be wrought, as hereafter will follow.

[Section. 11] But if there be very rich, or much other rich copper, and little of the light Contents, and that you cannot reach the right Addition, as above mentioned, then one must oft times add a rich fresh piece, viz. to three quar∣ters of a Centner of rich copper add three Centner of lead, and so the separating Work will prove rich: and although the Keinstocks may also remain rich to 4, 6 or 7 loths: yet they may further be added to the rich Copper, and the fresh pieces be so right, that the

refining lead may come out upon the true content, at six, or six and a half, or seven loths of Silver, at the highest.

[Section. 12] But, if there are poor contenty coppers (not to be re∣koned with the rich) yet you must do with them as be∣fore; but never take more than three quarters of a Cent∣ner of Copper to two or three quarters of a centner of lead, and if such black copper contains 8 loths, the cent∣ner of the separating work will contain two loths and an half of Silver: and the poor separating lead which comes from poor fresh may be added again to other fresh pieces, (as by the following Instructions may be seen) but there is no help for it, and, if possible, the poor fresh lead may be left alone.

Notes

• * 1.1

  One way of Preparati∣on doth most serve for Copper.
• * 1.2

  How much Lead to be used.
• * 1.3

  A profita∣ble Rule.