154 Bibliographical Notices. 
to ensure the fulness of beauty, aroma, and perfection that can be 
attained. The doctrine of Uniformity in the series of past changes 
in the animate.and the inanimate world, then, is the living thought 
that gives completeness of form and a charming spirit to Sir C. Lyell’s 
‘Principles of Geology.’ Every phenomenon of nature with which 
the geologist has to do, whether great or small, commonplace or 
wonderful, has its character and bearings studied fully and candidly, 
without the superstition and bonds of antiquity, on one side, leading 
us back to the mythic period of geology, and without the seeming 
cold-heartedness of ultra-positivism, on the other ; and all are made 
to show how long, how steadily, how ceaselessly, how perfectly the 
world’s work has been carried on. As the chief expounder of the 
disputed doctrine of Uniformity, Sir Charles stands on the highest 
point in the field of discussion, beyond, perhaps, most of his fol- 
lowers ; for some almost give up the hope of finding paleozoic mam- 
mals, some are weak in their belief in the absence of greater heat- 
agency in early times, and some begin to limit the earth’s age, as 
a cooled globe, to a hundred million years or so ; but it is well that 
his position should be clear to all good thinkers, if not perfectly in- 
controvertible ; and, indeed, he fairly uses all his facts for the sup- 
port of his view, without lessening their value to those who, think- 
ing differently, have to thank him for the conscientious care and 
painstaking labour by which he has brought together all that bears 
on the subject-matter of the ‘ Principles,’ from books, from people, 
and his own researches. The sources of information are indicated 
by many footnotes, and in the text too, or have been referred to in 
earlier editions ; and, indeed, it must be a matter of grave considera- 
tion to a geological writer now-a-days as to the extent to which 
references to published notions and descriptions should be introduced 
in the pages of a new work, unless he is anxious to leave popular 
writers and compilers no excuse for their careless habit of quoting 
opinions and statements at second hand, from such large and lead- 
ing works as that before us, and referring them to a wrong author- 
ship, instead of going to the fountain-heads in special memoirs and 
journals for the adopted facts and views. To those who take up a 
scientific subject for the first time, it is easy to refer details, princi- 
ples, and all to a favourite author, or perhaps to their only manual or 
book of study—anticipating the time when the science will be so far 
advanced that its accepted principles, formule, and practice will be 
universally applied, and pass, without reminder, as the result of the 
labours and thoughts of nearly forgotten men. Whilst, however, 
the science is still imperfect, let each geologist, be he gatherer of 
facts or builder of hypotheses, have the credit as well as the respon- 
sibility of his contributions to the general stock of knowledge. This 
is our author’s practice ; and hereby his work indicates the progress 
of modern geology among his contemporaries, as it supplies avowedly 
a history of geological thought and research in former times. 
The author himself supplies a list of the principal additions and 
corrections in this the tenth edition of the ‘ Principles.’ In vol. i., 
the ninth chapter, on the progressive development of organic life, 
