OF ARTS AND SCIENCES. 9 



brighter than its neighbors ; and it must be admitted that the photo- 

 graph is the best of photometers in such a case. 



In regard to the other three spectra of oxygen of Schuster we 

 have nothing to say ; but as far as concerns the spark spectrum 

 in air and the solar spectrum from wave-lengths 3749.8 to 5033.85 

 we can safely affirm that there is no physical connection between 

 them. 



