SCIENCE.— AD VER TISEMENTS. 



RARE MINERALS. 



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

 carbonate of calcium, pure white, 2Sc. 



EKDEMITE, bright yellow on red wulfenite, Arizona, SOc. 



Collections for Schools. 



ALPHA COLLECTION, tvventy-j3ve specimens in trays, con- 

 tained in a neat wooden box and accompanied by a 1,6- 

 page guide book (XIII., Guide for Science Teaching, Bos- 

 ton Society of Natural History), Price, complete, $1.00. 



CABINET COLLECTIONS, 100 specimens, small size, $S.OO. 

 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, packed, 

 $100.00. School Bulletin iusi ont. 



Loose Crystals. 



Small packages of free crystals for crystallographlc study 

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

 proval boxes of cabinet specimens by express or freight. 



ROY HOPPING, 



MINERAL DEALER, 



NEW YORK. 



504=506 Liberty Building, 

 Liberty and Greenwich Sts. 



Dec. 1, IS96. Just Published. Sixth Edition of 



THE MICROSCOPE ^SS^'^'fe^T^.l'bT" 



By SIMON HENRY GAQE, 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, greatlyenlarged, and illustrated 

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



COMSTOCK PUBLISHING CO., Ithaca, N. Y. 



The Thomas A. Scott Fellowship in Hygiene, 

 University of Pennsyivania. 



The Scott Fellowship in Hygiene at the University of Penn- 

 sylvania falls vacant October 1st, 1S',)7. Individuals desirous 

 of applying for appointment to the position can obtain de- 

 tails of the governing regulations by communicating with 

 Prof. A. C. Abbott, Director of the Laboratory of Hygiene, 

 University of Pennsylvania, Philadelphia. 



Popular Lect ures o n Astronomy 



MISS MARY PROCTOR 



(Daughter of the late Richard A. Proctor). 



SUBJECTS ... 



All Illustrated 



WITH STEREOPTICON 



Views. 



Other Worlds Than Ours 

 Flowers of the Sky. - - 

 An Eclipse Expedition. 



For circulars and terms, apply to 



Miss Mary Proctor, 



29 East 46th St., New York City. 

 Miss Proctor is now arranging dates for lectures during 

 the summer months, Chautauqua, etc. 



Horsford's Acid Phosphate 



Is the most effective and agreeable 

 remedy in existence for preventing in- 

 digestion, and relieving those diseases 

 arising from a disordered stomach. 



D. W. W. Gardner, Springfield, Mass., 

 says : "I value it as an excellent preventive of 

 indigestion, and a pleasant acidulated drink 

 when properly diluted with water and sweet- 

 ened." 



Descriptive pamphlet free on applit 

 Rumford Chemical Works, Providence, R. I. 



Bewarfc of Substitutes and Imitations. 



For sale by all Druggists. 



I will mail a finelv linished original photo, 

 cabinet size, of Sioux Indian Chief, SITTING 

 BULL, with his Signature. Have 200 sub- 

 jects, all different, of leading Western Indians. 

 First-class work. Cabinet Size for 10 cents each. Some sent 

 on selection. Give reference. After seeing sample you will 

 want others. - Indian Costume, Ornaments and Weapons. 

 15,000 Flint stone Ancient Indian Relics. 100,000 Mineral 

 and Fossil Specimens. Catalogue for stamp, loth year. 

 li. W. STIL"WELL,. Deadwood, Sonth Dak. 



HOUGH'S "AMERICAN WOODS" 



A publication illustrated by actual specimens. 



WOODS FOR THE STEREOPTICON 



Knabling you to show upon the screen characteristic 

 structures projected from nature itself. 



WOODS FOR THE MICROSCOPE 



Sections 1-1200 in. thick showing three distinct views of 

 grain under each cover glass. 



WOOD SPECIMENS FOR GLASS USE 



Nothing equals these for use in the class-room. 



VIEWS OF TYPICAL TREES 



From Nature, photographs and stereopticon views. 



WOODEN CROSS-SECTION CARDS 



Perfectly adapted to printing (with type or steel plate), 

 painting, India ink work, etc. 



If you are interested in wood or trees in any way send for 

 our circulars and sample specimens. 



Address R. B. HOUGH, Lowvllle, N. Y. 



