348 Mr John Lubbock’s Address. 
has taught us so much, we have still even more to learn. Why 
should some substances give few, and others many, lines? 
Why should the same substance give different lines at different 
temperatures? What are the oo. between the lines and 
the ie daean or chemical properti 
e may certainly look for aa new knowledge of the 
hidden actions of atoms and molecules from future researches 
that #9 so-called simple substances are in reality complex, 
and that their constituents oceur separately in the hottest 
regions of the solar atmosphere. Lockyer considers oie his 
researches lend great probability to this view. e whole sub- 
ject is one of intense interest, and we may rejoice test it is 
occupying the attention, not only of such men as Abney, 
ewar, Hartley, Liveing, Roscoe ea carers in our own 
country, but also of many foreign obser 
hen geology so greatly extended our airore of past time, 
the continued heat of the sun became a question of greater 
interest than ever. Helmholtz has shown that, while adopting 
the nebular hypothesis, we need not assume that. the nebulous 
matter was originally incandescent; but that its present high 
shrinking it will continue to give out light and heat, with little, 
i any; diminution for several millions of years. 
the sands of the sea, the stars of heaven have ever been 
aise as effective symbols of number, and the improvements in 
our methods of observation have added fresh force to our 
original impressions. We now know that our earth is but a 
fraction of one out of at least 75,000,000 worlds. 
But this is not all. In addition to the luminous heaven! 
bodies, we cannot doubt that there are countless others, invisi- 
ble to us from their greater distance, smaller size, or feebler 
light; indeed we know that there are many dark bodies which 
now emit no light or comparatively little. Thus in the case of 
movement of the visible star. Again I may refer to the curi- 
ous phenomena presented by Algol, a bright star in the head 
of Me usa. is star shines without change for two days and 
thirteen hours; then, in three hours and a half, dwindles from 
a star of the second to one of the fourth magnitude ; ; and 
