104 
THE GEOLOGIST. 
been myself, suggesting, as they do, ideas out of the beaten track. Indeed' 
from the editorial remarks which have appeared in several of the recent 
numbers, I perceive that to turn aside from the footprints of the Schools, 
and to tread in the stranger paths that point towards discovery, is an idio- 
syncrasy of your mind. 
But my object in addressing you is not to point out that which must be 
patent to all your readers, but rather to offer some remarks on the ideas 
which the articles referred to express. My remarks are principally made 
with reference to the note on " Ancient Climates." 
Before I come to a consideration of your own more immediate views upon 
the subject, as contained in the latter part of the paper, perhaps I should 
explain my opinions as regards what you rightly term one of the enigmas 
of geology — the maintenance on the earth's surface of a high temperature. 
Let us for a moment carry ourselves back in imagination to those early 
stages of the earth's existence to which science is unable to assign even a 
proijable date, and endeavour to appreciate, in the mind's eye, some of the 
conditions under which it laboured, when, glowing hot, it was first projected 
from the anvil of nature into those regions of the illimitable which were 
destined to be the scene of its career. I say glowing hot, because, although 
you imply that there is some reason to doubt its ever having suffered any 
great degree of heat, I for one have never entertained any opinion but 
that such was its state at one period. 
From the burning, seething mass arises a dark and dense atmosphere, of 
which carbon and carbonic acid formed the great ingredients, presenting 
as effectual a screen against the entrance of the sun's rays as it did to the 
escape of heat from the body of the planet it surrounded. Though the 
sun occupied its place as the centre, its attributes — light and heat — as far 
at least as our planet was concerned, were not experienced, " and darkness 
was upon the face of the deep." 
Gradually the external surface of this cloud-mantle radiated its heat 
into space — a very slow process, and one that might, have taken ages to 
get rid of five degrees of temperature — and allowed the large overplus of 
carbonic acid to be deposited in the forms of limestone and mineral coal. 
The earth was now no longer " without "form," but void. 
Let us suppose so long a time to have elapsed that already the fervid 
body of our globe has cooled down to a comparatively low temperature — 
the dense mantle that once shrouded her has partially dissipated itself, 
but a gloomy obscurity still hangs over her, calculated to hold heat in an 
eminent degree. Water appears next as water, that before formed an ele- 
ment of the atmosphere only ; in short, the waters were divided from the 
waters. The " firmament," as the early historian describes it, was not 
the cerulean expanse we are accustomed to see, but one of cloud scenery, 
through which the struggling sunbeams can with difficulty penetrate earth- 
wards, obedient to the mandate of the Creator, " Let theee be Light." 
After the appearance of land from out the waters which had been preci- 
pitated over the entire surface, vegetation made its way ; but was it at all 
like the vegetation of the present day ? I am inclined to think not. The 
part in nature that the vegetable world was to play had not been called 
on ; other scenes were taking place on the great stage from which the cur- 
tain had but just gone up ; the Deus ex mac/rind of creation had not 
come on, and the full strength of the company was not yet required. I 
conceive this early vegetation to have been of a very luxuriant, though, 
generally, of a/ri^i^Zc^s character, making up in mass of leaf and limb what 
it lacked in flower and fruit. This the large proportion of carbonic still 
in the atmosphere, and the dampness of the air, together with its high 
