H. Draper—Discovery of Oxygen in the Sun. 91 
tive strength and the general aspect of the lines in each case is 
ar. Ido not think that in comparisons of the spectra of 
] th 
cyanogen. When these gases were in Pliicker’s tubes a double 
series of photographs has been needed, one set taken with and 
the other without Leyden jars. : 
to the spectrum of nitrogen and the existence of this 
est effect for oxygen, the character of the evidence appears. 
The triple band between 4240, 4227, if traced upward into the 
sun has approximate representatives. Again at 4041, the same 
thing is seen, the solar bright line being especially marked. In 
another photograph the heavy line at 3996, which ne this pic- 
: o 
ture is 5 mt an insufficiently ex the solar 
Spectrum shows a comparison band in the sun. 
