him by these two volumes of Von Hoff's work, but, unlike
that author, he was able to visit the various localities referred to,
and to draw his own conclusions as to the nature of the changes which
must have taken place. It is pleasant to be able to relate that the
debt which he owed to Von Hoff was fully repaid by Lyell; for the
learned German's third volume appeared after the issue of the
_Principles of Geology_, and as Zittel assures us 'its influence on Von
Hoff is quite apparent in the third volume of his work[39].'

At this period, too, Lyell had the advantage of travelling both on the
continent and in various parts of Great Britain with the eminent French
geologist, Constant Prevost, who had shown his courage by opposing some
of the catastrophic teachings of the illustrious Cuvier himself.

Still more important to Lyell were the opportunities he enjoyed for
comparing his conclusions with those of Scrope, who had joined the
Geological Society in 1824, and became a joint secretary with Lyell in
the following year. From both of them, in their old age, I heard many
statements concerning the closeness and warmth of their friendship, and
the constant interchange of ideas which took place between them at this
time.

From Scrope, Lyell heard of the occurrence of great beds of freshwater
limestone in the Auvergne, on a far grander scale than in Strathmore,
with many other facts concerning the geology of Central France, which so
greatly excited him as in the end to alter all his plans concerning the
publication of his own book. As soon as Scrope's great work on Auvergne
was published, Lyell undertook the preparation of a review for the
_Quarterly_--and this review was a very able and discriminating
production.

Although Lyell did not derive his views concerning terrestrial evolution
directly from Hutton, as is sometimes supposed, there were two respects
in which he greatly profited when he came to read Hutton's work at a
later date.

In the first place, he was very deeply impressed by the necessity of
avoiding the _odium theologicum_, which had been so strongly, if
unintentionally, aroused by Hutton, of whom he wrote, 'I think he ran
unnecessarily counter to the feelings and prejudices of the age. This is
not courage or manliness in the cause of Truth, nor does it promote
progress. It is an unfeeling disregard for the weakness of human nature,
for it is our nature (for what reason heaven knows), but as _it is_
consti