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were improved in power and definition many of these objects 
which had formerly appeared diffuse were seen to be resolved 
into clusters of stars, and a presumption seemed to be raised 
that if several still resisted all attempts to resolve them it was 
only because the stars of which they were composed were so 
numerous within a given angular space, and individually so 
minute, as to baffle — hitherto at least — all attempts of opticians 
to construct telescopes powerful enough to resolve them. The 
magnificent speculations of Sir John Herschel are perhaps 
known to most of those here present. He regarded a nebula as 
something like the system composed of our own sun, and all the 
stars we can see with the naked eye, and even those more minute, 
placed at such an almost inconceivable distance that the whole 
subtends only a minute angle ; and that the individual stars, of 
which the system consists, can no longer be seen individually, 
even with telescopes, and we merely perceive a faint gleam of 
light emitted by the system as a whole. But a remarkable 
discovery made in recent years by Dr. Huggins rather leads us 
back towards the ideas of Laplace. Huggins found that, quite 
unlike the spectra of the sun and of the stars, the spectra of 
most of the irresolvable nebulae consisted of a very few bright 
lines, a character which laboratory experiments show to belong 
to the spectra of incandescent gases and vapours. This 
leaves little doubt that such must be the character of the 
matter of which these nebulae are formed. It would seem, 
a priori, that the matter of such masses must in time con- 
dense, and thus conceivably stars might be formed. And 
what strengthens this conclusion is, that many of these diffuse 
nebulae exhibit within them stellar points, so related to them 
that the chances are enormously against their being merely 
fixed stars casually situated in the same direction, and that 
these stellar points exhibit spectra of the same character as 
those of stars in general. 
Science, then, seems dimly to point to a fiery nebula as a 
condition of matter the most remote that we can go back to. 
Can we then deduce the existence of all that we see around 
us by the mere operation of self-acting laws from such a con- 
dition ? Or to take a starting-point not quite so far back, 
imagine our own earth to have cooled down to a temperature 
at which it would be possible for plants or animals, as we know 
them, to have existed ; can we imagine such springing into 
existence, so to speak, of their own accord ? Or to take a still 
later stage, supposing such forms of a low order once to exist, 
have we any scientific grounds for supposing that all that is 
required for the gradual formation of the higher forms, in- 
cluding man himself, is a slow process of natural evolution ? 
