Sir John Lubbock’s Address. - 845 
of the chromosphere could be seen only on the rare occasions 
of a total solar eclipse. Janssen and Lockyer, by the applica- 
tion of the spectroscope, have enabled us to study this region 
of the sun at all times. 
It is, moreover, obvious that the powerful engine of investi- 
gation afforded us by the spectroscope is by no means confined 
to the substances which form part of our system. The incan- 
descent body can thus be examined, no matter how great its 
distance, so long only as the light is strong enough. That this 
method was theoretically applied to the light of the stars was 
indeed obvious, but the practical difficulties were very great. 
Sirius, the brightest of all, is, in round numbers, a hundred 
millions of millions of miles from us; and, though as big as 
sixty of our suns, his light when it reaches us after a journey 
of sixteen years, is at most one two-thousand-millionth part as 
bright. Nevertheless as long ago as 1815 Fraunhofer recog- 
nized the fixed lines in the light of four of the stars, and in 1868 
ler and Huggins in our own country, and Rutherfurd in 
beautiful and mysterious lights contain many of the material 
substances with which we are familiar. In Aldebaran, for in- 
stance, we may infer the presence of hydrogen, sodium, magne- 
mous masses of luminous gas or vapor. Hor it is from matter 
In a gaseous state only that such light as that of the nebulz is 
know i 4 ” So far as observation has yet gone, 
nebula may be divided into two classes: some giving a contin- 
uous spectrum, others one consisting of bright lines. These 
latter all appear to give essentially the same spectrum, consist- 
Ing of a few bright lines. Two of them, in Mr. Huggins’s 
