HUMBOLDT LIBRARY 



or 



POPULAR SCIENCE LITERATURE. 



No. 24.] 



NEW YORK: J. FITZGERALD. 



[FIFTEEN CENTS. 



Entered at the New York Post-Officc u Second-Class Matter. 



$1.50 per Year, 

 (12 Numbers). 



PHC 



HDTOCOPfED BY 

 ^ .OVATION 

 i^SVICES j 



DATE. 



POPULAR 



SCIENTIFIC LECTTJBES, 



VIZ.: 



Off THE RELATION OF OPTICS TO PAINTING; ON THE ORIGIN OF THE. 



PLANETARY SYSTEM; ON THOUGHT IN MEDICINE; ON 



ACADEMIC FREEDOM IN GERMAN UNIVERSITIES. 



BY 



i 



H. HELMHOLTZ. 



?nOFESSOtt OK PHYSICS IN THE UNIVERSITY OF BKBUJT. 



ON THE RELATION OP OPTICS TO 

 PAINTING. 



KINO THE 6UBSTANCE OF A SERIES OF LEC- 

 TCBE3 DELIVERED IN COLOGNE, BEBLTN, AND 

 BONN. 



I FEAF. that the announcement of my inten- 

 tion to address yon on the subject of plastic 

 art may have created no little surprise among 

 some of my hearers. For I cannot doubt that 

 many of you have had more frequent oppor- 

 tunities of viewing works of art, and have 

 more thoroughly studied its historical aspects, 

 than I can lay claim to have done ; or indeed 



have had personal experience in the 

 practice of art, in which I am entirely want- 

 ing. I have arrived at my artistic studies by 

 a path which is but little trod, that i;by the 

 physiology of the senses ; and in referenoi 

 to those who have a long acquaintance with, 

 and who are quite at home in the beautiful 

 fields of art, I may compare myself to a trav 

 eller who has entered upon them by a stee 

 and stony mountain path, but who, in doi 

 so, has passed many a stage from whirV* 

 good point of view is obtained. If ther 

 I relate to you what I consider I ha ' 1C 

 served, it in with the tmderstandiaf ae . ' 



