380 On a Temporary Outburst of Light [July, 
dark lines ; between these and a line a little less refrangible than D, 
are a number of fine lines very near each other. About the place 
of solar D is a less strongly-marked line, and between’ that and the 
position of b in the solar spectrum there are numerous faint thin 
lines of absorption. Beyond 6, as far as the spectrum can be 
traced, are close groups of strong lines. This is the spectrum of 
the light of the photosphere interrupted by the special absorption 
of the cooler vapours which surround it. 
The spectrum of the light from a gaseous source consists of fine 
bright lines. These appear in the instrument, as they are repre- 
sented in the diagram, as if superposed upon the spectrum already 
described. The brightest of these lines was found by micrometric 
measures to coincide with Fraunhofer’s F. On the 17th, this ine 
was found by a simultaneous observation of it, with the lines of 
hydrogen, to agree exactly in position with the middle of the 
expanded line of hydrogen in the green. Another bright line 
occurs in the red, and appears to coincide with solar C and the red 
line of hydrogen. 
There are two bright lines more refrangible than TF’, and a fifth 
line was seen by glimpses near G of the solar spectrum. This may 
possibly comeide with the. blue line of hydrogen. 
The compound spectrum of the rapidly waning star was 
observed on several evenings up to May 28th. No important 
changes were noticed. From the 16th to the 20th the spectrum 
from the photosphere appeared to fade more rapidly than the 
bright lines from the gaseous source. 
The position of the groups of dark lines shows that the light of 
the photosphere, after passing through the absorbent atmosphere, 
is yellow. The light, however, of the green and blue bright Imes 
makes up to some extent for the green and blue rays (of other re- 
frangibilities) which have been stopped by absorption. To the eye, 
therefore, the star appears nearly white. However, as the star 
flickers, there may be noticed an occasional preponderance of yellow 
or blue. Mr. Baxendell, without knowing the results of prismatic 
analysis, describes the impression he received to be “as if the 
yellow of the star were seen through an overlying film of a blue 
tint.” 
These observations, with the prism, enable us to form the fol- 
lowing conclusions respecting the constitution of this remarkable 
star. There must be a photosphere of matter in the solid or liquid 
state emitting light of all refrangibilities. Surrounding this must 
exist also an atmosphere of cooler vapours, which give rise by 
absorption to the groups of dark lines. 
Besides this constitution, which it possesses in common with 
the sun and the stars, there must exist the source of the gaseous 
