SCIEN CE,. 



New Series 'R'rttiav AiTr'TTCTlO 1Q91 SfnocE Copies, 15 Cts. ''v-, '; 



VOL. LIV, No. 1389 FRIDAY, AUGUST XA, iVAi ^^^^^^ Subsckiption, $6.00 <? 



P' 





JENSEN. Dairy Bacteriology 



A new, practical work of great value and interest to all whVA,"^ ' with milk and milk 

 products in any capacity. \s ^ 



By Orla Jensen, Ph.D., Prof, of Technical Biochemistry, Polyu^rr, College, Copenhagen; 

 Formerly Director of the Swiss Experimental Dairy Station. Tra^^»^ d from the Danish 

 with Additions and Revisions by P. S. Arup, Sc.B. (Lond.), with 70 I. lustrations, Cloth, $3.00. 



The scientific character of this work as a whole renders it of international interest. It 

 has already been translated into several languages. The present edition may be considered 

 an entirely new one as Prof. Jensen has spared no time nor pains in correcting and adding 

 to the text, bringing it thoroughly up to date. 



COPAUX. Introduction to General Chemistry 



30 Illustrations, Cloth, $2.00. 



By H. CoPAux, Professor of Mineral Chemistry, School of Indicstrial Physics and Chemistry, 

 Paris. Translated by and with Appendix by Henry Leffmann, A.M., M.D., Member 

 American Chemical Society. 



An exposition of the principles of modern chemistry. 



CHAMBERLAIN. Textbook of Organic Chemistry 



Cloth, $4.00. 



By Joseph Scudder Chamberlain, Ph.D., Professor of Organic Chemistry, Massachusetts 

 Agricultural College. 



Attention has been centered upon Organic Chemistry during the recent progress in the 

 field of chemistry. This book meets the newer requirements. 



HACKH. Chemical Reactions and Their Equations 



Cloth, $1.75. 



By Ingo W. D. Hackh, Ph.C, A.B., Professor of Biochemistry, College of Physicians and 

 Surgeofts, San Francisco. 



It will enable anyone to balance any chemical equation rapidly and correctly. 



ROUGIER. Philosophy and the New Physics 



Cloth, $1.75. 



By Louis Rougier, Professeur Agrege de Philosophic, Docteur is Lettres. Authorized 

 Translation from the Author's Corrected Text of "La Materialisation de I'Energie." By 

 Morton Masius, M.A., Ph. D., Professor of Physics, Worcester Polytechnic Institute; Trans- 

 lator of M. Planck's " Theory of Radiation." 



BOOTH. Radiant Energy and the Ophthalmic Lens 



With 230 Illustrations. Cloth, ^2.25. 



By Frederick Booth. Introduction by Whitefield Bowers, A.B., M.D. (Indiana). 



Takes into account the newer theories of light. 



P. Blakiston^s Son & Co., Publishers, ''itZZ'T 



