EVOLUTION AND THEISM. 397 



after another of the nebulce, which Herschel regarded as con- 

 sisting of unconsolidated " fire-mist," has been resolved by the 

 superior power of modern telescopes into clusters of stars ; and 

 the mathematical reasoning of Laplace has been found not to 

 stand the test of a rigorous scrutiny. This may be freely granted ; 

 and yet the general doctrine that the material universe has come 

 into its present condition by a process of immense duration, and 

 not by a single creative act, has received such a vast amount of 

 support from new and unexpected sources, that I have no hesita- 

 tion in affirming it to be accepted by all who are most qualified 

 to judge, as having been now placed beyond the reach of dis- 

 cussion. Instead of starting from a hypothetical postulate, modern 

 science reasons backwards, — in astronomy as in geology, — from 

 phenomena presenting themselves to our own observation ; and I 

 shall briefly notice the orders of fads ^ilrich. seem to me of the 

 greatest evidentiary value. 



First in importance among these, is the certain distinction 

 which the Spectroscope now enables the astronomer to draw, 

 between the nebulae which are clusters of stars, and those which 

 consist of glowing gas. To the latter class belongs that great 

 nebula of Orion, which was long considered a sort of " crucial 

 instance " whereon the fate of the nebular hypothesis was to 

 turn. The prolonged and minute study which the late Lord 

 Rosse had made of this nebula, with the unequalled power (for 

 that particular object) of his six-foot reflector, had previously led 

 him to this conclusion ; but spectrum-analysis has placed it 

 beyond doubt ; and the fact acquires a new importance when the 

 doctrine of the Conservation of Energy is brought to bear upon it. 

 For " a nebulous body, in order to shine by its own light, must be 

 "hot, and must be losing heat through the very radiation by 

 " which we see it. As it cools, it must contract ; and this con- 

 " traction cannot cease, until it becomes either a solid body, or a 

 "system of such bodies, revolving round each other " (Newcomb). 



Another fact of supreme importance, resting not only on the 

 indications given by the spectroscope, but on chemical analysis 

 of the Meteorites, which have now been ascertained to be plane- 

 tary bodies revolving in regular orbits round the Sun, but to be 

 deflected from these by the Earth's attraction when we cross their 



