s 



1 



POPLLAR LECTUEES 



SCIENTIFIC SUBJECTS, 



BY 



H. HELMHOLTZ, 



PROFESSOR OF PHYSICS IX TUB UNIVERSITY OF BEUU.V. 



TEANSLATED BY 



E. ATKINSON, Pu.D. F.C.S. 



I'BOPKSSOR Off EXPERIMENTAL SCIENCE, STAFF COLLKOU. 



WITH AN INTRODUCTION 



BY \.-VvO; 

 PROFESSOR -TYND ALL. 



A 



NEW YOEK: 

 D. APPLETON AND COMPANY, 



1, 3, AND 5 BOND STREET. 



1885. 



