Hutton, on the
other, went to the wildest extremes in opposing each other's peculiar
tenets. Darwin tells us that he actually heard Jameson "in a field
lecture at Salisbury Craigs, discoursing on a trap-dyke, with
amygdaloidal margins and the strata indurated on each side, with
volcanic rocks all around us, say that it was a fissure filled with
sediment from above, adding with a sneer that there were men who
maintained that it had been injected from beneath in a molten
condition." ("L.L." I. pages 41-42.) "When I think of this lecture,"
added Darwin, "I do not wonder that I determined never to attend to
Geology." (This was written in 1876 and Darwin had in the summer of 1839
revisited and carefully studied the locality ("L.L." I. page 290.) It is
probable that most of Jameson's teaching was of the same controversial
and unilluminating character as this field-lecture at Salisbury Craigs.

There can be no doubt that, while at Edinburgh, Darwin must have become
acquainted with the doctrines of the Huttonian School. Though so young,
he mixed freely with the scientific society of the city, Macgillivray,
Grant, Leonard Horner, Coldstream, Ainsworth and others being among
his acquaintances, while he attended and even read papers at the local
scientific societies. It is to be feared, however, that what Darwin
would hear most of, as characteristic of the Huttonian teaching, would
be assertions that chalk-flints were intrusions of molten silica, that
fossil wood and other petrifactions had been impregnated with fused
materials, that heat--but never water--was always the agent by which
the induration and crystallisation of rock-materials (even siliceous
conglomerate, limestone and rock-salt) had been effected! These
extravagant "anti-Wernerian" views the young student might well regard
as not one whit less absurd and repellant than the doctrine of the
"aqueous precipitation" of basalt. There is no evidence that Darwin,
even if he ever heard of them, was in any way impressed, in his early
career, by the suggestive passages in Hutton and Playfair, to which
Lyell afterwards called attention, and which foreshadowed the main
principles of Uniformitarianism.

As a matter of fact, I believe that the influence of Hutton and Playfair
in the development of a philosophical theory of geology has been very
greatly exaggerated by later writers on the subject. Just as Wells
and Matthew anticipated the views of Darwin on Natural Selection,
but