11 



SCIENCE.— AD VERTISEMENTS. 



The Universuxn Clock 



represents the Universe. It shows the earth revolving round 

 its axis, giving the time at the point passing the sun, the 

 stars in their proper position, and their rising and setting. 



The Northern Heznispliere Clock 



shows at a glance the time at every place between the North 

 Pole and Equator. 



UNIVERSUM CLOCK CO., 1 BEACON ST.. BOSTON, MASS. 



HOUGH'S "AMERICAN WOODS" 



A publication illustrated by actual, specimens. Prepaea 

 TioNS OF Woods fob Steeeopticon and Microscope, Speci- 

 mens OF Woods foe Class Use, Etc. If you are interested 

 in woods or trees in any way, send for our circulars and 

 sample specimens. Address 



R. B. HOUGH, LOWVILLE, N. Y. 

 An elementary treatise on 



THE CALCULUS, 



BY JOHN Graham, b. a., B. e. 



Spon & Chamberlain, 12 Cortlandt St., N. Y. 



The Physical Review. 



A JOURNAL OF EXPERIMENTAL AND 

 THEORETICAL PHYSICS. 



conducted by 



Edward L. Nichols, Ernest Merritt, and Frederick Bedell. 



XXI. 



November— December, 1896. 



TABLE OF CONTENTS. 



The Specific Heats of the Metals. F. A. Waterman. 

 Experimental Determinations of the Temperature 

 Geissler Tubes. R. W. Wood. 



The Viscosity of Mercury Vapor. 



Goodwin. 



A. A. NoYES and H. M. 



Minor Contributions: (1) An Example in Thermometry 

 A. 8. Cole and E. L. Durgan. (2) A Study of the Appar- 

 ent Capacity of Condensers for short-charge Periods H 

 V. Carpenter. (3) Note on the Osmotic Theory of the 

 Voltaic Cell. H M. Goodwin. (4) The Division of an 

 Alternating Current in Parallel Circuits with Mutual 

 Induction. F. Bedell. (5) On the Specific Gravity and 

 Electrical Conductivity of the Normal Solutions of So- 

 dium and Potassium Hydroxides, and Hydrochloric Sul- 

 phuric, Nitric, and Oxalic Acids. E. H. Loomis. 



Notes: (1) The Buffalo Meeting of the American Association 

 for the Advancement of Science. (2) The British Asso- 

 ciation for the Advancement of Science. 



Published Bi-monthly, Annual Subscription, $3.00. 

 PUBLISHED FOR CORNELL UNIVERSITY. 



THE MACMILLAN COMPANY, NEW YORK. 



Horsford's Acid Phosphate 



Overworked men and women, the 

 nervous, weak and debilitated, will find 

 in the Acid Phosphate a most agree- 

 able, grateful and harmless stimulant,, 

 giving renewed strength and vigor to 

 the entire system. 



Dr. Edwin F. Vose, Portland, Me., says: 

 ' ' I have used it in my own case when suffering 

 from nervous exhaustion, with gratifying results. 

 I have prescribed it for many of the 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. 



NEW CATALOGUE. 



We have recently issued a new edition, revised and 

 enlarged to 64 pages, of our Catalogue of 



Books on Chemistry, Chemical 

 Technology in Physics. 



It is arranged by subjects, and includes all the 

 standard books in Chemical and Physical Science, a» 

 well as the recent 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. 



in the country to-day offers so high a class of 

 Indian Stone Relics as I am now offering to- 

 advanced collectors, having recently bought 

 several collections, giving every type of Ar- 

 rov?' and Spear Heads from % inch to 7 inches. Drills, Axes, 

 Celts, Pipes, Mortars, Pestles, Hematites, Banner Stones, Amu- 

 lets, also, European Stone Relies. Nothing surpasses and few 

 approach my stock of 15,000 pieces. Goods sent on selection. 

 Catalogue for stamp. Also Catalogue, No. 8, Minerals, Fos- 

 sils, etc. L. W. STILWELL, Deadwood, South Dak. 



I 



COLLECTIONS OF MINERALS. 



Scientifically selected, arranged and labeled. Uneqalled for beauty and practical value. 



MINERALS FOR LABORATORY WORK. 



Sold by the pound at very low prices. 



CABINET SPECIMENS in greatest variety. 



124-page Illustrated Catalogue, 25c. in paper, 50c. in cloth. 

 44-page Illustrated Price-Lisis, 4c. ; Bulletins and Circulars Free. 



GEO. L. ENGLISH & CO., Mineralogists, 64 East 12th St., New York. 



