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; 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, touchstones, 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 et Causis Subterraneorum. This work also has always been published in company with others. The first edition was printed at Basel, 1546; the second at Basel, 1558, which, being the edition revised and added to by the author, has been used by us for reference. There are five "books," and in the main they contain Agricola's philosophical views on geologic phenomena. The largest portion of the actual text is occupied with refutations of the ancient philosophers, the alchemists, and the astrologers; and these portions, while they exhibit his ability in observation and in dialectics, make but dull reading. Those sections of the book which contain his own views, however, are of the utmost importance in the history of science, and we reproduce extensively the material relating to ore deposits in the footnotes on pages [43] to [52]. Briefly, Book I. is devoted to discussion of the origin and distribution of ground waters and juices. The latter part of this book and a portion of Book II. are devoted to the origin of subterranean heat, which he assumes is in the main due to burning bitumen—a genus which with him embraced coal—and also, in a minor degree, to friction of internal winds and to burning sulphur. The remainder of Book II. is mainly devoted to the discussion of subterranean "air", "vapour", and "exhalations", and he conceives that volcanic eruptions and earthquakes are due to their agency, and in these hypotheses he comes fairly close to the modern theory of eruptions from explosions of steam. "Vapour arises when the internal heat of the earth or some hidden fire burns earth which is moistened with vapour. When heat or subterranean fire meets with a great force of vapour which cold has contracted and encompassed in every direction, then the vapour, finding no outlet, tries to break through whatever is nearest to it, in order to give place to the insistent and urgent cold. Heat and cold cannot abide together in one place, but expel and drive each other out of it by turns".
As he was, we believe, the first to recognise the fundamental agencies of mountain sculpture, we consider it is of sufficient interest to warrant a reproduction of his views on this subject: "Hills and mountains are produced by two forces, one of which is the power of water, and the other the strength of the wind. There are three forces which loosen and demolish the mountains, for in this case, to the power of the water and the strength of the wind we must add the fire in the interior of the earth. Now we can plainly see that a great abundance of water produces mountains, for the torrents first of all wash out the soft earth, next carry away the harder earth, and then roll down the rocks, and thus in a few years they excavate the plains or slopes to a considerable depth; this may be noticed in mountainous regions even by unskilled observers. By such excavation to a great depth through many ages, there rises an immense eminence on each side. When an eminence has thus arisen, the earth rolls down, loosened by constant rain and split away by frost, and the rocks, unless they are exceedingly firm, since their seams are similarly softened by the damp, roll down into the excavations below. This continues until the steep eminence is changed into a slope. Each side of the excavation is said to be a mountain, just as the bottom is called a valley. Moreover, streams, and to a far greater extent rivers, effect the same results by their rushing and washing; for this reason they are frequently seen flowing either between very high mountains which they have created, or close by the shore which borders them.... Nor did the hollow places which now contain the seas all formerly exist, nor yet the mountains which check and break their advance, but in many parts there was a level plain, until the force of winds let loose upon it a tumultuous sea and a scathing tide. By a similar process the impact of water entirely overthrows and flattens out hills and mountains. But these changes of local conditions, numerous and important as they are, are not noticed by the common people to be taking place at the very moment when they are happening, because, through their antiquity, the time, place, and manner in which they began is far prior to human memory. The wind produces hills and mountains in two ways: either when set loose and free from bonds, it violently moves and agitates the sand; or else when, after having been driven into the hidden recesses of the earth by cold, as into a prison, it struggles with a great effort to burst out. For hills and mountains are created in hot countries, whether they are situated by the sea coasts or in districts remote from the sea, by the force of winds; these no longer held in check by the valleys, but set free, heap up the sand and dust, which they gather from all sides, to one spot, and a mass arises and grows together. If time and space allow, it grows together and hardens, but if it be not allowed (and in truth this is more often the case), the same force again scatters the sand far and wide.... Then, on the other hand, an earthquake either rends and tears away part of a mountain, or engulfs and devours the whole mountain in some fearful chasm. In this way it is recorded the Cybotus was destroyed, and it is believed that within the memory of man an island under the rule of Denmark disappeared. Historians tell us that Taygetus suffered a loss in this way, and that Therasia was swallowed up with the island of Thera. Thus it is clear that water and the powerful winds produce mountains, and also scatter and destroy them. Fire only consumes them, and does not produce at all, for part of the mountains—usually the inner part—takes fire."
The major portion of Book III. is devoted to the origin of ore channels, which we reproduce at some length on page [47]. In the latter part of Book III., and in Books IV. and V., he discusses the principal divisions of the mineral kingdom given in De Natura Fossilium, and the origin of their characteristics. It involves a large amount of what now appears fruitless tilting at the Peripatetics and the alchemists; but nevertheless, embracing, as Agricola did, the fundamental Aristotelian elements, he must needs find in these same elements and their subordinate binary combinations cause for every variation in external character.
Bermannus. This, Agricola's first work in relation to mining, was apparently first published at Basel, 1530. The work is in the form of a dialogue between "Bermannus," who is described as a miner, mineralogist, and "a student of mathematics and poetry," and "Nicolaus Ancon" and "Johannes Naevius," both scholars and physicians. Ancon is supposed to be of philosophical turn of mind and a student of Moorish literature, Naevius to be particularly learned in the writings of Dioscorides, Pliny, Galen, etc. "Bermannus" was probably an adaptation by Agricola of the name of his friend Lorenz Berman, a prominent miner. The book is in the main devoted to a correlation of the minerals mentioned by the Ancients with those found in the Saxon mines. This phase is interesting as indicating the natural trend of Agricola's scholastic mind when he first comes into contact with the sciences to which he devoted himself. The book opens with a letter of commendation from Erasmus, of Rotterdam, and with the usual dedication and preface by the author. The three conversationalists are supposed to take walks among the mines and to discuss, incidentally, matters which come to their attention; therefore the book has no systematic or logical arrangement. There are occasional statements bearing on the history, management, titles, and methods used in the mines, and on mining lore generally. The mineralogical part, while of importance from the point of view of giving the first description of several minerals, is immensely improved upon in De Natura Fossilium, published 15 years later. It is of interest to find here the first appearance of the names of many minerals which we have since adopted from the German into our own nomenclature. Of importance is the first description of bismuth, although, as pointed out on page [433], the metal had been mentioned before. In the revised collection of collateral works published in 1558, the author makes many important changes and adds some new material, but some of the later editions were made from the unrevised older texts.