336 THEORIES OF ORE DISPOSITION HISTORICALLY CONSIDERED. 



RESULTS ACHIEVED. 



The wide divergence of vieAvs shown by these discussions to be held 

 by recognized authorities on the subject might lead one to conclude 

 that we are as far as ever from a universal agreement on accepted 

 theories. A more deliberate consideration of the progress of investi- 

 gation and verification during this last period, which has been but too 

 briefly and imperfectly set forth in the preceding pages, will show, 

 however, that the advance in this direction has been real and perma- 

 nent as far as regards the later stages of ore formation, which are 

 more susceptible of actual proof, and that the disagreement lies rather 

 with the ultimate or more theoretical sources of derivation, which 

 must always remain to some extent matters of opinion. 



UIBLIOGRAPHY. 



It being considered unadvisable to print a full list of works con- 

 sulted during the pre})aration of the preceding paper, titles of those 

 only that contain important bibliographies on ore deposition are 

 appended. 



A. G. Werner: Neiie Theorie von der Entstebung der GJlnge. Freiberg, 170 1. 



.1. Waldiiuf V. Waldenstehi : Die besonderen Lagerstatten der nutzbaren Min- 



eralien. Wien, 1S24. 

 K. A. Kiibn : Ilandlmeb der Geognosie. 11"" band. Freiberg, 183(1 



B. V. Cotta u. II. Miiller: (Jangstudien, I'" I)and. Freiberg, ISoO. 

 Jobann (irinnn : Die Lagerstiitten der nntzb;iren Mineralien. Prag, 18()0. 

 Gonzalo y Tarin : Memorias de la comite del niai)a geologico de Espaiia. Madrid, 



18S8. Tom. II. pp. 73-181. 

 E. Fuchs et L. De Lauuay : Traite des gites niinrraux et metallifi-res. I. Paris, 



1893. 

 K. A. V. Zittell : History of Geology and Paleontology. Translation by Airs. 



Ogilvie-Gordon. London, 1001. 

 Richard Beck : Lehre von den Erzlagerstiitten. Berlin, 1901. 2d ed., 1903. 



