BxLibria 

 C. K. OGDEtf 



POPULAR LECTURES 



ON 



SCIENTIFIC SUBJECTS. 



BY 



H. HELMHOLTZ, 



PROFESSOR OF PHYSICS EST THE UMVEliSITT OF BERLIN. 

 TRANSLATED BY 



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



PROFESSOR OF EX PE RIMKNT A I, SCIENCE, STAFF COLLEGE. 



FIRST SERIES. 

 WITH AN INTRODUCTION by PROFESSOR TTNDALL 



(fcbitian. 



LONDON : 

 LONGMANS, GREEN, AND CO. 



1881. 



All rights reserved. 



