6 S. F. EMMONS — THEORIES OF ORE DEPOSITION 



Among the ideas current in his time, Agricola, as a result of his obser- 

 vations, promptly rejected the views that veins were formed contempo- 

 raneously with the primary rocks of the globe, and that the planets had 

 an influence in the formation of the metals ; but he seems to have had 

 very few positive ideas of his own as to their origin, though inclining 

 to ascribe vein-filling to material brought in by circulating waters. He 

 still entertained the idea of a lapidifying juice which he conceived as 

 giving to water the power of absorbing earth and of corroding metals, 

 and which might have formed fossil casts as well as minerals. His use 

 of the term a fossilia " for both minerals and petrifications, which was 

 retained by subsequent geological writers, especialty those of the Wer- 

 nerian school, is often a cause of misconception among modern readers 

 who have occasion to consult the older works on geology and mineralogy. 



For over a century after Agricola there appears to have been little 

 written that had any special bearing on ore deposits, but toward the 

 close of the seventeenth century there was an apparent awakening of 

 interest in regard to their origin among reflective men who had to do 

 directly or indirectly with mines, which may probably have been 

 prompted by the theories of the Cosmic philosophers, so that by the 

 close of the eighteenth century there had accumulated considerable 

 speculative literature on this subject. 



The following is a list of the more frequently quoted works that ap- 

 peared during this period, with the approximate dates of their pub- 

 lication: 



"Speculum Metallurgise politissimum," by Bergmeister Balthasar Rosier (1700). 



" Physica subterranea," by J. J. Becher. Commentated by G. S. Stahl. Second 

 edition (1703). 



" Pyritologia," by J. F. Henkel, professor of chemistry and mineralogy, Freiberg 

 (1725). 



" Obersachsiche Bergakademie," by C. F. Zimmermann, councillor of mines (1749). 



11 Markscheidekunst," by Von Oppell, vice-director of Saxon mines (1749). 



" Abh. v. d. Metalmuttern," etcetera, by D. J. H. Lehman, director of Prussian 

 mines (1753). 



" Elementa Metallurgiae Chemicse," by W. J. Wallerius, Stockholm (1768). 



"Ursprung d. Gebirge u. Erzadern," etcetera, by C. F. Delius, professor of metal- 

 lurgy at Schemnitz (1770). 



" Mineral. Geograph. d. Kursachsische Lander," by J. F. W. de Charpentier, director 

 of Saxon mines (1778). 



"Unterirdische Geographie," by I. G. Baumer, Giessen (1779). 



"Gesch. d. Metallreichs," by C. A. Gerhard, councillor of mines (1781). 



"Erfahr. ii. d. Innern d. Gebirge," by F. M. H. v. Trebra, vice-director of Han- 

 overian mines (1785). 



"Beobacht. ii. d. Hartz Gebirge," by Lieutenant G. O. S. Lasius, engineer on land 

 survey of Hanover (1787). 



