These Are Wiley Books 



READY OCTOBER 1st. 

 Elements of Optical Minerals 



An Introduction to Microscopic Petrography. 



By N. H. WlNCHELL and A. N. WlNCHELL. Second Edition. En- 

 tirely Rewritten and Much Enlarged by ALEXANDER N. WlNCHELL, Doct. 

 Univ. of Paris, Professor of Mineralogy and Petrology, University of Wisconsin. 

 Part I. — Principles and Methods. 



The treatment given in this first Part of the second edition, taking up 

 Principles and Methods, is adapted to the microscopic study of Minerals, both 

 in thin sections and in powdered form immersed in liquids, 

 the latter method permitting an accurate quantitative measurement of the index 

 of refraction. 



(Now going through the press — ready October 1st.) 



The Famous 'Dana' Mineralogies 



Textbook of Mineralogy System of Mineralogy 



With an Extended Treatise on 

 Crystallography and Physical Miner- 

 alogy. Third Edition, Ee vised and 

 Enlarged by WILLIAM E. FORD. 

 720 pages, 6 by 9, 1050 figures, $5.00 



Manual of Mineralogy 



Thirteenth Edition, entirely Ee- 

 vised and Eewritten by WILLIAM E. 

 Ford. 



460 pages, 6 by 9, 357 figures, 10 plates. 

 Cloth, $3.00. Flexible binding, $3.50. 



(Descriptive Mineralogy.) Sixth 

 Edition, with Appendices I and II, 

 completing the work to 1909. 

 1323 pages, 6fby 10, over 1400 figures; 

 half leather, $15.00. 



(Third Appendix to "System," 

 completing the work to 1915, by WlL= 

 LI AM E. FORD, issued in separateform. 

 87 pages, 6f by 10, cloth, $2.00.) 



Minerals and How to 

 Study Them 



A Book for Beginners in Miner- 

 alogy. 

 380 pages, 5 by 7, 319 figures, $2.00. 



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