594 APPENDIX A 



De Natura FossiUum. 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 (i) " 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) " com- 

 pounds " (homogeneous " mixtures " of simple substances, thus forming 

 such minerals as galena, pyrite, etc.). In this classification Agricola en- 

 deavoured 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 four- 

 score 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 ; Book II., 

 " earths " clay, Lemnian earth, chalk, ochre, etc. ; Book III., " solidified 

 juices " salt, nitrum (soda and potash), saltpetre, alum, vitriol, chrysocolla, 

 caeruleum (part azurite), orpiment, realgar, and sulphur ; Book IV., camphor, 

 bitumen, coal, bituminous shales, amber ; Book V., lodestone, bloodstone, 

 gypsum, talc, asbestos, mica, calamine, various fossils, geodes, emery, touch- 

 stones, pumice, fluorspar, and quartz ; Book VI., gems and precious stones ; 

 Book VII., " rocks " marble, serpentine, onyx, alabaster, limestone, etc. ; 

 Book VIII., metals gold, silver, quicksilver, copper, lead, tin, antimony, 

 bismuth, iron, and alloys, such as electrum, brass, etc. ; Book IX., various 

 furnace operations, such as making brass, gilding, tinning, and products such 

 as slags, furnace accretions, pompholyx (zinc oxide), copper flowers, litharge, 

 hearth-lead, verdigris, white-lead, red-lead, etc. ; Book X., " compounds," 

 embracing the description of a number of recognisable silver, copper, lead, 

 quicksilver, iron, tin, antimony, and zinc minerals, many of which we set 

 out more fully in Note 8, page 108. 



De Ortu el Causis Subterraneorum. This work also has always been 

 published in company with others. The first edition was printed at Basel, 



1 See footnote 4, page i. *System of Mineralogy. 



