SCIENCE-ADVERTISEMENTS 



Biology 



Physics 



Have You Read 

 These Four Important Books 



The Electron : Its Isolation and 

 Measurement and the Determination 

 of Some of Its Properties. By Robert 

 A. Mil,l,iKAN, Professor of Physics in 

 the University of Chicago. Price 

 $1.50, postpaid $1.60. The volume 

 presents in a most interesting manner 

 the results of the author's extensive 

 research as a pioneer in this field. It 

 describes some of the most significant 

 properties of the elementary electrical 

 unit, the electron, and discusses the 

 bearing of these properties upon the 

 two most important problems of mod- 

 ern physics; the structure of the atom 

 and the nature of electro-magnetic 

 radiation. 



Problems of Fertilization. By 



Frank R. LilliE, Professor of Em- 

 bryology and Chairman of the Depart- 

 ment of Zoology, the University of 

 Chicago. Price $1.75, postpaid $1.85. 

 Its purpose is to concentrate on the 

 moment of fertilization itself, and to 

 give a critical statement of the pro- 

 gress of investigation on this subject 

 up to the present time. As the prob- 

 lem deals with the union of the male 

 and the female sex elements which 

 form the beginning of each individ- 

 ual's life-history, it has an important 

 bearing on the problems of heredity. 



The Origin of the Earth. By 



Thomas C. Chamberi,in, Head of 

 the Department of Geology, the Uni- 

 versity of Chicago. Price $1.50, post- 

 paid $1.60. The book sets forth the 

 disclosures that led to the rejection, 

 one after another, of the older views 

 of the origin of our planet, the futile 

 attempts then made to amend these 

 or to build others upon the same 

 foundations, the final rejection of 

 these, and the construction of a rad- 

 ically new view based on a new dy- 

 namic foundation. 



Food Poisoning. By Edwin 

 Oakes Jordan, Chairman of the De- 

 partment of Hygiene and Bacteriology, 

 the University of Chicago. Price 

 $1.00, postpaid Sl.lO. This book pre- 

 sents in an interesting and readable 

 manner the results of a thorough in- 

 vestigation into the extent of food 

 poisoning, various kinds of food 

 poisoning, articles of food most com- 

 monly connected with food poisoning, 

 causes and prevention of food poison- 

 ing. 



THE UNIVERSITY OF CHICAGO PRE5S 



5811 Ellis Avenue 



CHICAGO, ILLINOIS 



Geology 



Chemistry 



