INFLUENCE OF GEOLOGICAL STRUCTURE. 215 
remarks is too self-evident to need support ; for it is 
a matter of daily observation, that, other things be- 
ing equal, such individuals of any given population 
who live by labour requiring constant skill, ingenu- 
ity, and judgment, will exhibit far greater powers of 
reasoning and thought, and will, in fact, be in every 
respect mentally superior to those who merely fol- 
low some routine occupation that requires no exer- 
cise of the rational faculties. De la Beche, speak- 
ing of the inhabitants of Cornwall, in England, re- 
marks, " The variation in the mental condition of 
the people in this district is remarkably striking. 
This variation is, no doubt, due to many local causes, 
but among them the geological structure of the coun- 
try would appear to hold a more important place 
than might at first sight, perhaps, be anticipated. 
The chief contrast would probably be found between 
the labourers on the poor lands of the carbonaceous 
series of northwestern Devon and the miners of 
Cornwall, both considered in the mass. While the 
former are thinly distributed over the country, full 
of prejudices against improvement, and still often 
firm believers in witchcraft, ghosts, &c., the miners 
are thickly congregated in the neighbourhood of the 
working beds, abound with intelligence, and, /row 
the constant exercise of their judgment^ upon which, 
indeed, the living of a large population entirely de- 
pends, able to take correct and enlarged views of 
many other subjects than those immediately con- 
nected with their ordinary occupations. The mi- 
ners, nevertheless, in Cornwall and Devon, labour 
under considerable disadvantages as regards educa- 
tion, when compared with those of many other 
countries, where mining colleges or schools are 
founded. But the necessity of studying the vary- 
ing condition of their lodes has, nevertheless, so 
est there must be the greatest moral power. It is the manual 
labour required in the one case, and not the other, which makes 
all the dijference. 
