
Recent Scientific Publications 

HicciNs' Lessons in Physics. 
Conn’s Bacteria, Yeasts, and Molds in the Home. 
Young’s Manual of Astronomy. 
BERGEN’s Botany Note-book. 
BERGEN’s Elements of Botany. Revised Edition now ready. 
MxiER's Herbarium and Plant Description. 
With Directions for Collecting, Pressing and Mounting Specimens, 
McGrecory’s Manual of Quantitative Chemical Analysis. 
MILLIKAN’s Mechanics, Molecular Physics, and Heat. 
MILLER’s Laboratory Physics. 


GINN & COMPANY PUBLISH LEADING TEXT-BOOKS IN ALL 
DEPARTMENTS OF SCIENCE. CORRESPONDENCE WILL RECEIVE 
PROMPT ATTENTION. 
GINN & COMPANY Publishers 
BOSTON. NEW YORK, CHICAGO, LONDON. 


THE 
| PHYSICAL REVIEW 
A JOURNAL OF EXPERIMENTAL AND 
HEORETICAL PHYSICS 
American Physical Society 
WARD L. NICHOL 
ERNEST MERRITT, AND F iré CPGE ERBEN 

Twentieth Volume eus JANUARY 1905 
PUBLISHED MONTHLY ANNUAL SUBSCRIPTION $5.00 | 
SAMPLE COPY UPON REQUEST : 
THE MacMILLAN COMPANY, 
66 FIFTH AVENUE, NEW YORK : 






