Chapter XLI: Appendix: A

AGRICOLA'S WORKS.

Georgius Agricola was not only the author of works on Mining and allied subjects, usually associated with his name, but he also interested himself to some extent in political and religious subjects. For convenience in discussion we may, therefore, divide his writings on the broad lines of (1) works on mining, geology, mineralogy, and allied subjects; (2) works on other subjects, medical, religious, critical, political, and historical. In respect especially to the first division, and partially with regard to the others, we find three principal cases: (_a_) Works which can be authenticated in European libraries to-day; (_b_) references to editions of these in bibliographies, catalogues, etc., which we have been unable to authenticate; and (_c_) references to works either unpublished or lost. The following are the short titles of all of the published works which we have been able to find on the subjects allied to mining, arranged according to their present importance:--_De Re Metallica_, first edition, 1556; _De Natura Fossilium_, first edition, 1546; _De Ortu et Causis Subterraneorum_, first edition, 1546; _Bermannus_, first edition, 1530; _Rerum Metallicarum Interpretatio_, first edition, 1546; _De Mensuris et Ponderibus_, first edition, 1533; _De Precio Metallorum et Monetis_, first edition, 1550; _De Veteribus et Novis Metallis_, first edition, 1546; _De Natura eorum quae Effluunt ex Terra_, first edition, 1546; _De Animantibus Subterraneis_, first edition, 1549.

Of the "lost" or unpublished works, on which there is some evidence, the following are the most important:--_De Metallicis et Machinis_, _De Ortu Metallorum Defensio ad Jacobum Scheckium_, _De Jure et Legibus Metallicis_, _De Varia Temperie sive Constitutione Aeris_, _De Terrae Motu_, and _Commentariorum, Libri VI_.

The known published works upon other subjects are as follows:--Latin Grammar, first edition, 1520; Two Religious Tracts, first edition, 1522; _Galen_ (Joint Revision of Greek Text), first edition, 1525; _De Bello adversus Turcam_, first edition, 1528; _De Peste_, first edition, 1554.

The lost or partially completed works on subjects unrelated to mining, of which some trace has been found, are:--_De Medicatis Fontibus_, _De Putredine solidas partes_, etc., _Castigationes in Hippocratem_, _Typographia Mysnae et Toringiae_, _De Traditionibus Apostolicis_, _Oratio de rebus gestis Ernesti et Alberti_, _Ducum Saxoniae_.

REVIEW OF PRINCIPAL WORKS.

Before proceeding with the bibliographical detail, we consider it desirable to review briefly the most important of the author's works on subjects related to mining.

_De Natura Fossilium._ This is the most important work of Agricola, excepting _De Re Metallica_. It has always been printed in combination with other works, and first appeared at Basel, 1546. This edition was considerably revised by the author, the amended edition being that of 1558, which we have used in giving references. The work comprises ten "books" of a total of 217 folio pages. It is the first attempt at systematic mineralogy, the minerals[1] being classified into (1) "earths" (clay, ochre, etc.), (2) "stones properly so-called" (gems, semi-precious and unusual stones, as distinguished from rocks), (3) "solidified juices" (salt, vitriol, alum, etc.), (4) metals, and (5) "compounds" (homogeneous "mixtures" of simple substances, thus forming such minerals as galena, pyrite, etc.). In this classification Agricola endeavoured to find some fundamental basis, and therefore adopted solubility, fusibility, odour, taste, etc., but any true classification without the atomic theory was, of course, impossible. However, he makes a very creditable performance out of their properties and obvious characteristics. All of the external characteristics which we use to-day in discrimination, such as colour, hardness, lustre, etc., are enumerated, the origin of these being attributed to the proportions of the Peripatetic elements and their binary properties. Dana, in his great work[2], among some fourscore minerals which he identifies as having been described by Agricola and his predecessors, accredits a score to Agricola himself. It is our belief, however, that although in a few cases Agricola has been wrongly credited, there are still more of which priority in description might be assigned to him. While a greater number than fourscore of so-called species are given by Agricola and his predecessors, many of these are, in our modern system, but varieties; for instance, some eight or ten of the ancient species consist of one form or another of silica.

Book I. is devoted to mineral characteristics--colour, brilliance, taste, shape, hardness, etc., and to the classification of minerals;