406 
THE GEOLOGIST. 
survey there has been fouiideil a startling generalization. Tlie intcUeetual 
races, if they did exist, must have lived at a distance from the ferocious animals 
that may have occupied tiie seas or jungles of the ancient world, and conse- 
quently their remains could not have been found in the ordinary fossUiferous 
strata. Theh dwelling-places may have been in one or more of the numerous 
localities of our continents not yet explored, or in those immense regions of the 
earth which are now covered by the great oceans of the globe ; and tiU these 
oceans have quitted their beds, or some great convulsions have upheaved and 
laid bare the strata above wliich the races in question may have lived and diedj 
■we are not entitled to maintain it as a demonstrated truth that the ancient 
earth was under the sole dominion of the brutes that perish." I confess I do 
not see that if intellectual races have existed prior to man, they must, as a 
matter of necessity, have lived at a distance from the ferocious animals which 
then peopled the world : they may have built habitations and fabricated instru- 
ments of defence. But as we find traces neither of these nor of themselves, 
and yet discover remams of pre-adamite animals, it must be concluded that the 
supposed mtellectual races could not have resided amongst them. Yet I agree 
with Dr. Brewster that the generaUzation is hasty and unfounded ; although 
far more probable than the forn\er assumption, it is equally illogical. As a 
deduction it is quite as unsound. 
As an illustration of the shutting-out of causes, if I may use such a term, 
and the reducing of all phenomena to a few, Avliich has rightly been said to be a 
passion with philosophers, geologists have rather cut short the origin of springs 
and lakes. 1 think that the following explanation has never received a place 
among others: they may arise from cavil ics running iidaud from below the 
level of the sea, and terminating either upon or below the surface of the land, 
thus forming either sprmgs or lakes. Accordmg to this hypothesis the depth 
of such a lake, for it is not said that all lakes and springs are thus formed, 
would be determined by the height of the land where the cavity or sandy 
passage reached its surface, and the height of springs would vary in the same 
mamier ; according to the depth of the sandy cavity below the level of the sea 
would be depth or height of lakes or spruigs thus formed, supposing this hy- 
pothesis be received as correct. 
Proceeduig to the third question, there is little difficulty in discovering that 
after convulsions have ruptiu'cd the once orderly arrangement of the sedi- 
mentary and igneous rocks, it is easy to perceive that mountain ranges have 
been caused by upheaval. This species of geolog'ical power produces flaws in 
the shape of contortions and faults, which volcame power can alone bring to 
pass ; the gradual enlargement and duuinutiou produced by present stratifica- 
tion and disintegration produces regular series of rocks, wherein occur no 
faults or other imperfections. It is probable that when the earth was formed, 
the igneous rocks cooled so as to allow the materials of our present aqueous 
rocks to be gradually precipitated upon them. Hence regular strata would be 
the result, and for once assuming an hypothesis to be true, from this it must 
be that the various mountain-ranges were called into existence after this event, 
and that the defective strata which form them, and all which occur, are the 
work of after volcanic agency. It may be thought that I here condemn myself 
by assuming that which ought to be absolutely proved. But I would urge 
that such an uifereuee as this is hi the highest degree probable, and thus may 
be assumed as demonstrated, in wliicli it differs, although only in degree, yet 
\ immeasurably from the inferences already noticed. 
The development of this latter question has lead many to theorize altogether 
apart from experience, when no real advancement of knowledge has, from the 
\ nature of such a course of conduct, ensued. Logic has been separated from 
experience ; men have argued metaphysically instead of physically ; and thus. 
