il SCIENCE.— AD VERTISEMENTS. 
Scientific Apparatus 
“ Bowboin”? X-RAY Focus TUBE. 
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age Batteries; Electrical Measuring Instruments ; Phys- 
ical and Optical Apparatus; Pyschological Apparatus, 
ete. 
‘¢ Duty Free’’ Importations from all prominent 
European makers. 
Correspondence requested. 
JAMES G. BIDDLE, 
Dealer, Manufacturer’s Agent and Importer, 
909 Drexel Building, PHILADELPHIA. 
Exhaustion 
Horsford’s Acid Phosphate. 
Overworked men and women, the 
nervous, weak and debilitated, will find 
in the Acid Phosphate a most agree- 
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giving renewed strength and vigor to 
the entire system. 
Dr. Edwin F. Vose, Portland, Me., says: 
“¢T have used it in my own case when suffering 
from nervous exhaustion, with gratifying re- 
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various forms of nervous debility, and it has 
never failed to do good.” 
Descriptive pamphlet free on application to 
Rumford Chemical Works, Providence, R. I. 
Beware of Substitutes and Imitations. 
For sale by all Druggists. 
Dec. 1, 1896. Just Published. Sixth Edition of 
THE MICROSCOPE AND MICROSCOPI- 
CAL METHODS, 
By SIMON HENRY GAGE, 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 figuresin the text. Price, $1.50, postpaid. 
COMSTOCK PUBLISHING CO., Ithaca, N. Y. 
Hi H A large collection of Upper 
Cambrian Fossils. Mississippi Cambrian fossils 
from the St. Croix (Potsdam) sandstone for sale. Mostly 
Trilobites. Send for low prices. 
W. A. FINKELNBURG, WINONA, MINN. 
NEW CATALOGUE. 
We have recently issued a new edition, revised and en- 
larged to 64 pages, of our catalogue of 
Books on Chemistry, Chemical 
Technology and Physics. 
It is arranged by subjects, and includes all the standard 
books in Chemical and Physical Science, as well asthe 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. 
EFor 12 Cents 
I will mail a finely finished original photo, 
cabinet size, of Sioux Indian Chief, SITTING 
BULL, with his Sibnetire Have 200 sub- 
jects, all different, of leading Western Indians. 
First-class work. Cabinet Size for 10 centseach. Some sent 
on selection. Givereference. 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. 13th year. 
L. W. STILWELL, Deadwood, South Dak. 
HOUGH’S “AMERICAN WOODS” 
A publication illustrated by actwal specimens. 
WOODS FOR THE STEREOPTICON 
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 of 
grain under each cover glass. 
WOOD SPECIMENS FOR CLASS 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, ete. 
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. 
