an that
of the first.

In March 1831, Lyell had accepted the Professorship of Geology in King's
College, London. In addition to his desire to aid in the work of
scientific education, in which he had always taken so great an interest,
Lyell seems to have felt that the task of presenting his views in a
popular form would be aided by his having to expound them to a
miscellaneous audience. For two years, these lectures were delivered,
and attracted much attention; the favourable impressions produced by
them on a man of the world have been recorded by Abraham Hayward, and on
more scientific thinkers by Harriet Martineau.

The third volume of the _Principles_ was not completed till a second
edition of the second volume had been issued. This third volume,
appearing in May 1833, dealt with the classification of the Tertiary
strata, to which Lyell had devoted so much labour, studying conchology
under Deshayes, and visiting all the chief Tertiary deposits of Europe
for the collection of materials. The application of the principles
enunciated in the two earlier volumes to the unravelling of the past
history of the globe, constituted the chief task undertaken in this part
of the great work. But not a few controversial questions were dealt
with, and the famous 'metamorphic theory' was advanced in opposition to
the Wernerian hypothesis of 'primitive formations.' The volume was
appropriately dedicated to Murchison, who had been Lyell's companion in
the famous Auvergne excursion, which had produced such an effect on his
mind.

Within a twelvemonth, a third edition of the whole work in four small
volumes was issued, and in the end no less than twelve editions of the
_Principles of Geology_ were issued, in addition to portions separately
published under the titles of _Manual_, _Elements_, and _Student's
Elements of Geology_, of all of which a number of editions have
appeared. Lyell was always the most painstaking and conscientious of
authors. He declared 'I must write what will be read[59],' and he spared
no labour in securing accuracy of statement combined with elegance of
diction. His father, a good classical and Italian scholar, had done much
towards assisting him to attain literary excellence, and at Oxford,
where he took a good degree in classics, he was greatly impressed by the
style of Gibbon's writings, and practised both prose and poetic
compositions with great diligence.

Both Darwin and Huxley always maintained that the r