SCIENCE.— AD VEB TISEMENTS. 



RARE MINERALS. 



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

 carbonate of calcium, pure white, 25c. 



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



Collections for Schools. 



ALPHA COLLECTION, twenty-flve 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, $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, packed, 

 $100.00. /School BuUetmiasl out. 



Loose Crystals. 



Small packages of free crystals for crystallographic 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. 1,1896. Just Published. Sixth Edition of 



THE MICROSCOPE ^SlTe^t^hI'LT- 



By SIMON HENRY QAQE, 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. 



A large collection of Upper 

 Mississippi Cambrian fossils 



from the St. Croix (Potsdam) sandstone for sale. Mostly 



Trilobltes. Send for low prices. 



W. A. FINKCLNBURG, WiNONA, MiNN. 



Cambrian Fossils. 



NEW CATALOGUE. 



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

 larged to 6-1 pages, of our catalogue of 



Books on Chemistry, Cbemical 

 Teclinology and Pliysics. 



It Is arranged by subjects, and includes all the standard 

 books in Chemical and Physical Science, as well as the re- 

 cent literature up to date. 



A copy of this Catalogue will be sent free by mail to any 

 address. 



D. Van Nostrand Company, 



Publishers and Importers of Scientific Books, 

 23 Murray St. and 27 Warren St., New York. 



Horsford's Acid Phosphate 



with water and sugar only, makes a 

 delicious, healthful and invigorating 

 drink. 



Allays the thirst, aids digestion, and 

 relieves the lassitude so common in 

 midsummer. 



Dr. M. H. Henrj'. New York, says : "When 

 completely tired out by prolonged wakefulness 

 and overwork, it is of the greatest value to me. 

 As a beverage it possesses charms beyond any- 

 thing I know of in the form of medicine. 



Descriptive pamphlet free. 



Rumford Chemical Works, Providence, R. 1. 



Beware of Substitutes and Imitations. 



X*c>3r 12 CJexrtEt 



I will mail a finely finished 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. Alter 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. 13tb year. 

 li. W. STILWEIili, Deadwood, South Dak. 



HOUGH'S "AMERICAN WOODS" 



A publication illustrated by actual specimens. 



WOODS FOR THE STEREOPtlCON 



Enabling 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 oi 

 grain under each cover glass. 



WOOD SPECIMENS FOR CLASS USE 



Nothing equals these ior 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 worij, etc. 



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

 our circulars and sample specimens. 



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



