Messrs. Huggins and Miller on Spectra of Fixed Stars. 75 
line may be due to calcium, since the small difference between 
the position of the thallium line and that of one of the calcium 
lines very close to it, would not be distinguishable with the dis- 
persive power of the apparatus employed. 
In the spectra of the other elements which we compared with 
that of the star, no coincidences occur. There is no line coinci- 
dent with the red line C of Aydrogen ; but in the star are two 
strong lines, one on either side of the position of C: there is 
also no line coincident with F. It is strikingly confirmatory 
of this methed of analysis, that in all the stars hitherto ex- 
amined by us in which a line corresponding to C exists, that 
corresponding to F is also found. When F is absent, C is also 
wanting. In nitrogen three strong double lines were compared. 
In tin five lines, and in lead two bright lines were compared, 
but no coincidence was found. 
e€ star. : 
The spectra of iron and manganese were also compared with 
that of the star, but the state of the atmosphere prevented any 
certain conclusion. The lines in the spectra of nitrogen, tin, and 
mercury, were not coincident with any definite Jines in the star- 
tram. Neither of the hydrogen lines corresponding to C and 
was present. nae ; 
The absence in the spectrum of ¢ Orionis, and also in the spec- 
trum of ¢ Pegasi which so closely resembles it in character, of 
corresponding to those of hydrogen, is an observation of 
considerable interest. It is of the more importance since the 
doubt might be entertained, and it might be suspected that they 
