426 
ME. W. HUGGINS AND DR. W. A. MILLER ON 
(3) Calcium. — Four lines of this metal were on two different occasions seen to be 
coincident with four lines in the spectrum of the star. 
(4) Iron. — The double line of this metal at E, and three other more refrangible bright 
lines, coincide with lines in the star-spectrum. 
(5) Bismuth. — In the spectrum of this metal also four lines were found to coincide 
with four in the stellar spectrum. 
Thallium. — The bright green line so characteristic of this metal appears to coincide 
with one of the lines seen in the star-spectrum ; but this 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 dispersive power 
of the apparatus employed. 
In the spectra of the other elements which we compared with that of the star, no 
coincidences occur. 
Hydrogen. — There is no line coincident with the red line C of hydrogen ; 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 method of analysis, that in all 
the stars hitherto examined by us in which a line corresponding to C exists, that corre- 
sponding 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. 
Gold. — The strongest of the gold lines approximates closely in position to one in the 
spectrum of the star, but it is probably not coincident. 
Three of the strong lines of cadmium , two of silver , four of mercury , two of barium , 
and one (the orange line) of lithium were observed to be not coincident with any of the 
lines visible in the star. In these comparisons, when barium was used, it was employed 
in the form of a nearly solid amalgam. 
The opening of the slit was maintained at the same width (not more than the -g-jjoth 
of an inch) for all the observations, both with Aldebaran and a Orionis. In the case of 
the fainter star which follows, it was very slightly widened. 
13. (3 Pegasi. — The colour of this star is a fine yellow. In the general arrangement 
of the groups, in the gradation of the strength of the lines composing the groups, and 
in the absence of the hydrogen lines, this spectrum, though much fainter, is closely 
analogous with the spectrum of a Orionis, as figured in the Plate. 
This star was carefully observed on many different occasions ; but the faintness of the 
star, and the unfavourable state of the atmosphere on many of the nights of observa- 
tion, did not permit the same number of lines to be measured, nor allow a comparison 
with an equal number of terrestrial elements. From November 10, 1862, when twelve 
lines were observed, to the present year, we have scrutinized the star carefully. 
Nine of the elements were compared with the spectrum of (3 Pegasi. Two of these, 
viz. sodium and magnesium , and perhaps a third, viz. barium , furnish spectra in which 
there are lines which coincide with lines in the spectrum of the star. 
