Physics and Chemistry. 275 
at a tension a little less than that of the atmosphere. e line in 
or twenty-five miles per second, as part of its motion would be 
masked by the motion of the earth in the opposite direction. e 
coincidence of a second line in the spectrum of the great nebula 
hydrogen. The author could find no terrestrial line corresponding 
to the third line of the nebula. 
_ The great intensity of the light of Sirius and the four strong 
its spectrum, render it well suited for exammation. The 
m 
second. On examining the spectrum of a solar Spots the author 
found as he had previously done, that there was a distinct incre: 
in the thickness of Fraunhofer’s lines. There was no absorption 
ine in the spectrum of the umbra, which was not present In that 
- the sun’s normal surface, nor was any ordinary solar line want- 
The spectrum of the comet discovered by Winnecke and by 
uet on June 13th, 1868, was also examined. With two prisms 
By care 
of carbon under different ‘nbeseeinialcti Mr. Huggins believes t 
he has shown that the light of the comet II of 1868, is identical 
With that emitted by highly heated vapor of carbon,—PAil. Trans 
ations for 1868, p. 529. ‘ Ww 
