SCIENCE— ADVERTISEMENTS 



Two New 

 McGRAW-HILL 

 Books- — 



LOEB— 



PROTEINS AND THE THEORY 



OF COLLOIDAL BEHAVOIR 



By Jacques Loeb 



Member of the Rockefeller Institute for Medical Research 



INTERNATIONAL CHEMICAL SERIES 



292 pages, 51^ X 8, illustrated, $3.00 



A book that furnishes the proof of the stoichiometrical 

 character of the reactions of proteins, and develops a mathe- 

 matical and quantitative theory of colloidal behavior on 

 the basis of Donnan's theory of membrane equilibria. 



BELL— 



THE TELESCOPE 



By Louis Bell, Consulting Engineer 

 285 pages, 6x9, illustrated, $3.00 



The first adequate book on the telescope since Sir 

 William Herschel's treatise, published a century ago. It 

 deals primarily with principles and their application to large 

 and small instruments. It traces the development of the 

 telescope, describes modern instruments in detail, discusses 

 specially such topics as eye-pieces, mountings, accessories, 

 hand telescopes and binoculars, and gives accurate instruc- 

 tions for the setting up, housing, testing and care of tele- 

 scopes. 



Send for copies of these nezv books on approval 



McGRAW-HILL BOOK CO., Inc. 



Penn Terminal Building 

 370 Seventh Avenue New York 



