Spectra of the Stars and Planets. 491 
the aid of a quartz prism. At this time I did not happen to 
and accurate researches on the visible dBase of the spectra of 
e some attempts in this 
might be determined with precision. SOI 
the spring of 1873 I published a paper on the diffraction 
Pectrum of the Sun, illustrated by a photograph seas 
ue region from wave length 4350 near G to 3440 near O, an 
1 the fall of the same year took photographs of the spectra 
OF keveral non-metals, notably nitrogen, carbon, and oxygen. 
