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812 BROADWAY, NEW YORK 

 SIXTH EDITION. 



THE MICROSCOPE ^^crJirTST- 



By SIMON HENRY OAQE, Professor of Microscopy, His- 

 tology and Embryology in Cornell University and the 

 New York State Veterinary College, Ithaca, N. Y., U.S A. 

 Sixth edition, rewritten, greatly enlarged, and illustrated 

 by 165 figures in the text. Price, $1.50, postpaid. 



COMSTOCK PUBLISHING CO., Ithaca, N. Y. 



NEW CATALOGUE. 



We have recently issued a new edition, revised and en- 

 larged to 64 pages, of our catalogue of 



Books on Cliemistry, Chemical 

 Technology and Physics. 



It is arranged by subjects, and includes all the standard 

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 cent literature up to date. 



D. Van Nostrand Company, 



Publishers and Importers of Scientific Bool<s, 

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RARE MINERALS. 



THAUMASITE, from Paterson, N. J., a sulphate, silicate and 

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EKDEIWITE, bright yellow on red wulfenite, Arizona, 50c. 



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Collections for Schools. 



ALPHA COLLECTION, twenty-five specimens in trays, con- 

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CABINET COLLECTIONS, 100 specimens, small size, $5.00. 

 100 specimens, large size, $10.00. These specimens are 

 each accompanied by a label giving name, system of 

 crystallization, chemical formula, and locality, and make 

 a good working collection for a student. 



EXCELSIOR COLLECTION for high schools and colleges, 

 200 specimens, nicely mounted on wooden blocks, with 

 beveled fronts for receiving labels. Price, pacl^ed, 

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Loose Crystals. 



Small packages of free crystals for crystallographic study 

 may be sent for inspection by mail at small cost. Ap- 

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ROY HOPPING, 



MINERAL DEALER, 

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Horsford's Acid Phosphate." i] 



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Now Ready, 



Light, Visible and Invisible. 



By SILVANUS P. THOMPSON, D.Sc, 



F.R.S.f M.H.L, Pi'ineipal of, and Professor of Physics in^. 



the City and Guild's Technical College, 



Pinsbury, London. 



With Numerous Illustrations. 

 12ino. Cloth, pp. xii + 294. Price $1.50. 



CONTENTS OF THE VOLUME: 



Light and Shadows. 



The Visihle Spectrum and the Eye. 



Polarization o£ Light. 



The Invisihle Spectrum ( ttltra-violet part). 



The Invisible Spectrum (infra-red part). 



Eontgen Light. 



This volume brings up to date the late discoveries and- 

 theories, and it will be found invaluable both to the student 

 and to the general reader. The subject is treated in a sim- 

 ple, masterly, and, at the same time, popular way. 



THE MACMILLAN COMPANY, 



66 Fifth Avenue, New York. 



