on, Sedgwick, who was in the chair, was so far
influenced by the arguments brought forward by the young men, as to lend
some aid to those who had come to be called the 'Fluvialists,' in
contradistinction to the 'Diluvialists'; he went so far as to suggest
that, with regard to the floods which the Catastrophist invoked, it
would be wiser at present to 'doubt and not dogmatise[50].'

To what extent the MS. of the _Principles_, sent to the publisher in
1827, was added to and altered two years later, we have no means of
knowing; but that the work was to a great extent rewritten would appear
from a letter sent to Murchison by Lyell, just before his return to
England. In it, he says:--

'My work is in part written, and all planned. It will not pretend to
give even an abstract of all that is known in geology, but it will
endeavour to establish _the principle of reasoning_ in the science; and
all my geology will come in as illustration of my views of those
principles, and as evidence strengthening the system necessarily arising
out of the admission of such principles, which, as you know, are neither
more nor less than that _no causes whatever_ have from the earliest time
to which we can look back to the present, ever acted, but those that are
_now acting_, and that they never acted with different degrees of energy
from that which they now exert'; but in 1833, in dedicating his third
volume to Murchison, he refers to the MS., completed in 1827, as a
'first sketch only of my _Principles of Geology_[51].'

At one period, Lyell contemplated again delaying publication till he had
visited Iceland. In the end, however, after declining to act as
professor of geology in the new 'University of London' (University
College), he set himself down steadily to the task of seeing the book
through the press. It was at this time that Lyell experienced a singular
piece of good fortune, comparable with that which befel Darwin thirty
years afterwards, by his book falling into the hands of a very
sympathetic reviewer. John Murray, who had undertaken the publication of
the _Principles_, was also the publisher of the _Quarterly Review_, and
Lockhart, the editor of that publication, undertook that an early notice
of the book should appear, if the proof-sheets were sent to the
reviewer. Buckland and Sedgwick were successively approached on the
subject of reviewing Lyell's book, but both declined on the ground of
'want of time'; though I strongly suspec