BOOK VII. 



The method of assaying ore used by mining people, differs from 

 smelting only by the small amount of material used. Inasmuch as, by 

 smelting a small quantity, they learn whether the smelting of a large 



determining quantitative values, which is the fundamental object of the assayer's art, and 

 all their discussion is shrouded in an obscure cloak of gibberish and attempted mysticism. 

 Nevertheless, therein lies the foundation of many cardinal assay methods, and even of 

 chemistry itself. 



The first explicit records of assaying are the anonymous booklets published in German early 

 in the i6th Century under the title Probierbiichlein. Therein the art is disclosed well advanced 

 toward maturity, so far as concerns gold and silver, with some notes on lead and copper. We 

 refer the reader to Appendix B for fuller discussion of these books, but we may repeat here 

 that they are a collection of disconnected recipes lacking in arrangement, the items often 

 repeated, and all apparently the inheritance of wisdom passed from father to son over many 

 generations. It is obviously intended as a sort of reminder to those already skilled in the 

 art, and would be hopeless to a novice. Apart from some notes in Biringuccio (Book in. 

 Chaps. I and 2) on assaying gold and silver, there is nothing else prior to De Re 

 MetalUca. Agricola was familiar with these works and includes their material in this chapter. 

 The very great advance which his account represents can only be appreciated by comparison, 

 but the exhaustive publication of other works is foreign to the purpose of these notes. 

 Agricola introduces system into the arrangement of his materials, describes implements, and 

 gives a hundred details which are wholly omitted from the previous works, all in a manner 

 which would enable a beginner to learn the art. Furthermore, the assaying of lead, copper, 

 tin, quicksilver, iron, and bismuth, is almost wholly new, together with the whole of the 

 argument and explanations. We would call the attention of students of the history of 

 chemistry to the general oversight of these early i6th Century attempts at analytical 

 chemistry, for in them lie the foundations of that science. The statement sometimes made 

 that Agricola was the first assayer, is false if for no other reason than that science does not 

 develop with such strides at any one human hand. He can, however, fairly be accounted as the 

 author of the first proper text-book upon assaying. Those familiar with the art will be astonished 

 at the small progress made since his time, for in his pages appear most of the reagents and most 

 of the critical operations in the dry analyses of gold, silver, lead, copper, tin, bismuth, quick- 

 silver, and iron of to-day. Further, there will be recognised many of the " kinks " of the art 

 used even yet, such as the method of granulation, duplicate assays, the " assay ton " method of 

 weights, the use of test lead, the introduction of charges in leaf lead, and even the use of beer 

 instead of water to damp bone-ash. 



The following table is given of the substances mentioned requiring some comment, 

 and the terms adopted in this book, with notes for convenience in reference. The German 

 terms are either from Agricola's Glossary of De Re MetaUica, his Interpreiaiio, or the 

 German Translation. We have retained the original German spelling. The fifth column 

 refers to the page where more ample notes are given : — 



