

PROCEEDINGS 



OF THE 



AMERICAN ACADEMY 



OP 



ARTS AND SCIENCES. 



VOL. XXIII. 

 PAPERS READ BEFORE THE ACADEMY. 



Investigations on Light and Heat, made and published wholly or in part with 

 Appropriation from the Rumford Fund. 



I. 



CONTRIBUTIONS FROM THE PHYSICAL LABORATORY OF 

 HARVARD UNIVERSITY. 



OXYGEN IN THE SUN. 



By John Trowbridge and C. C. Hutchins. 



Presented March 9, 1887. 



Since the time when it was announced that hydrogen existed in 

 great abundance in the sun's atmosphere and was a controlling element 

 in its economy, there have been no more interesting questions in solar 

 physics than those touching the presence of other gases in the sun's 

 body and atmosphere ; and when we consider the important part 

 that oxygen plays in terrestrial affairs, the great variety of combina- 

 tions into which it enters, and its high constituent percentage in the 

 composition of the earth itself, a peculiar interest, second to that of no 

 other element perhaps, attaches to its probable presence in the sun. 



The investigation of the spectrum of oxygen as a research by itself, 

 and as connected with its presence in the sun, has occupied many emi- 

 nent physicists ; but the fact that the latest and most complete inves- 

 tigations have left the minds of scientific men still in doubt has 

 led the writers to take up the question again with more perfect and 

 powerful apparatus and increased facilities, in order if possible to 

 add something to the knowledge of the subject. 

 vol. xxiii. (n. s. xv.) 1 



