il SCLIENCE.—ADVERTISEMENTS. 
NEW SCIENTIFIC BOOKS—Just Ready or in Press 
The Liquefaction of Gases 
Just Ready. Irs RisE AND DEVELOPMENT. Cloth, 12mo, $1.50. 
By WILLerT LePLEY HARDIN, Harrison Senior Fellow in Chemistry in the University of Penn- 
sylvania. 
A complete history of the development of the methods employed in the liquefac- 
tion of gases, as the following clipping from the preface will show : 
Popular “Recent developments in the liquefaction of air and the recent liquefaction of hydro- 
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Scope of “The object of this little volume is to present a complete history of the development 
the Book of the methods employed in the liquefaction of gases. Sufficient theory has been given to 
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Industrial The various forms of apparatus are shown in illustrations. In addition to the history 
Application of the development of the methods, the condition of matter at the critical point, the theory 
of the gaseous and liquid states of matter, and the theory of the regenerative method of 
refrigeration are also considered. In the conclusion, a brief outline is given of researches 
at low temperatures and of the industrial application of liquefied gases. 
THOMPSON—Light Visible and Invisible. ; SUTER—-Handbook of Optics. For Sru- 
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nus P. THompson, D.Sc., M.R.I., F.R.S., author woop SuTER, M.D., Professor of Ophthalmology, 
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the usual text-books on Refraction of the Eye. 
BURBURY—A Treatise on the Kinetic 
Theory of Gases. By S. H. Burpury, M.A., 
F.R.S., late Fellow of St. Johns, Cambridge. 
8vo, Cloth. Price, $2.00 net. 
LANGE—Our Native Birds. How To PRo- 
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By D. LANGE, Instructor in Nature Study in the 
Schools of St. Paul, Minn., author of a ‘‘ Manual 
Cambridge University Press. of Nature Study.” Cloth, 12mo. Nearly Ready. 
MACBRIDE—The Slime Moulds. A HAanp- LENGFELD—Inorganic Chemical Prepa= 
BOOK OF NORTH AMERICAN MYXOMYCETES. By rations. By FreLix LENGFELD, Assistant Pro- 
THOMAS H. MACBRIDE, Professor of Botany, Uni- fessor of Inorganic Chemistry in the University of 
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A list of all species described in North America This book gives directions for making about fifty 
including Central America. Each description is ac- | substances, and is intended for college students with 
companied by annotations. some knowledge of analytical chemistry. 
Blowpipe Analysis 
By Freperick Hurron German, Instructor in Chemistry in Stamford High School. Cloth, 
16mo. Just Ready. 60 cents net. 
This little book is designed for use in high Sete and also to serve as an aid to college students in 
the study of qualitative analysis. 
THE MACMILLAN COMPANY, Publishers, New York. 
