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solidified on its exterior, owing to the cooling action of the 
surrounding air. The celebrated Laplace went still further, 
and, from a consideration of Herschel’s researches on nebulae, 
propounded his so-called nebulous theory of the earth’s origin, 
according to which our sphere owed its existence to the aggre- 
gation and condensation of nebulous matter. The state of the 
natural sciences of the period was not, however, sufficiently 
advanced to furnish means by which this theory of Laplace 
could be either confirmed or disproved, so that it was long 
looked upon as a visionary hypothesis which was never even 
imagined as likely to be so far confirmed by future discoveries 
in science, as to become at this moment the most plausible 
explanation of a beginning of our world which has as yet been 
put forward. 
This being the case, our chapter of genesis commences by 
assuming the nebulous theory of the origin of our globe as the 
starting-point ; and the first stage in the history of the earth is 
consequently the act of aggregating or segregating the nebu- 
lous matter in space or, in other words, of gathering together 
in a gasiform condition the chemical elements of which the 
earth, with its surrounding atmosphere, is actually com- 
posed of. 
The consequence of the coming together of these elements 
would, as chemistry teaches us, result in their reacting upon one 
another with intense energy, giving rise to the development of 
both light and heat, and forming numerous chemical combina- 
tions, the nature of which would be dependent upon the 
mutual affinities of the elements themselves, and the relative 
proportions in which they were respectively present in this 
admixture of gases and vapours. The more simple or binary 
compounds would naturally be formed first, such as the oxides, 
sulphides, chlorides, &c. ; but these in turn would combine 
inter se producing salts and other compounds, amongst which 
the silicates played a very prominent part. 
The final result of this great display of chemical energy 
would be to change entirely the nature and appearance of the 
original nebulous gathering of gasiform matter, for as soon as 
the chemical action had come to an end, by far the largest 
proportion of the newly-formed substances would no longer be 
able to retain the gasiform condition at the lower temperature 
which then ruled, and would be condensed into fluids, when 
the whole would assume the shape of a sphere of molten 
matter surrounded by an intensely heated atmosphere of . such 
of the other compounds and free elements as could still remain 
volatile at this temperature. 
This period might be termed the second stage in the history 
of the earth, and if examined into more closely, it would be 
