Geological Observations of Volcanic Islands | Page 5

a volcanic country is most delightful; besides
the interest attached to itself, it leads you into most beautiful and retired
spots. Nobody but a person fond of Natural History can imagine the
pleasure of strolling under cocoa-nuts in a thicket of bananas and
coffee-plants, and an endless number of wild flowers. And this island,
that has given me so much instruction and delight, is reckoned the most
uninteresting place that we perhaps shall touch at during our voyage. It
certainly is generally very barren, but the valleys are more exquisitely
beautiful, from the very contrast. It is utterly useless to say anything
about the scenery; it would be as profitable to explain to a blind man
colours, as to a person who has not been out of Europe, the total
dissimilarity of a tropical view. Whenever I enjoy anything, I always
look forward to writing it down, either in my log-book (which increases
in bulk), or in a letter; so you must excuse raptures, and those raptures
badly expressed. I find my collections are increasing wonderfully, and
from Rio I think I shall be obliged to send a cargo home."
The indelible impression made on Darwin's mind by this first visit to a
volcanic island, is borne witness to by a remarkable passage in the
"Autobiography" written by him in 1876. "The geology of St. Jago is
very striking, yet simple; a stream of lava formerly flowed over the bed
of the sea, formed of triturated recent shells and corals, which it has
baked into a hard white rock. Since then the whole island has been
upheaved. But the line of white rock revealed to me a new and
important fact, namely that there had been afterwards subsidence round
the craters which had since been in action, and had poured forth lava. It
then first dawned on me that I might perhaps write a book on the
geology of the various countries visited, and this made me thrill with
delight. That was a memorable hour to me, and how distinctly I can call
to mind the low cliff of lava beneath which I rested, with the sun
glaring hot, a few strange desert plants growing near and with living
corals in the tidal pools at my feet."

Only five years before, when listening to poor Professor Jameson's
lectures on the effete Wernerianism, which at that time did duty for
geological teaching, Darwin had found them "incredibly dull," and he
declared that "the sole effect they produced on me was a determination
never so long as I lived to read a book on Geology, or in any way to
study the science."
What a contrast we find in the expressions which he makes use of in
referring to Geological Science, in his letters written home from the
"Beagle!" After alluding to the delight of collecting and studying
marine animals, he exclaims, "But Geology carries the day!" Writing to
Henslow he says, "I am quite charmed with Geology, but, like the wise
animal between two bundles of hay, I do not know which to like best;
the old crystalline group of rocks, or the softer and more fossiliferous
beds." And just as the long voyage is about to come to a close he again
writes, "I find in Geology a never-failing interest; as it has been
remarked, it creates the same grand ideas respecting this world which
Astronomy does for the Universe." In this passage Darwin doubtless
refers to a remark of Sir John Herschel's in his admirable "Preliminary
Discourse on the Study of Natural Philosophy,"--a book which
exercised a most remarkable and beneficial influence on the mind of
the young naturalist.
If there cannot be any doubt as to the strong predilection in Darwin's
mind for geological studies, both during and after the memorable
voyage, there is equally little difficulty in perceiving the school of
geological thought which, in spite of the warnings of Sedgwick and
Henslow, had obtained complete ascendancy over his mind. He writes
in 1876: "The very first place which I examined, namely St. Jago in the
Cape de Verde Islands, showed me clearly the wonderful superiority of
Lyell's manner of treating Geology, compared with that of any other
author, whose works I had with me, or ever afterwards read." And
again, "The science of Geology is enormously indebted to Lyell--more
so, as I believe, than to any other man who ever lived...I am proud to
remember that the first place, namely, St. Jago, in the Cape de Verde
Archipelago, in which I geologised, convinced me of the infinite
superiority of Lyell's views over those advocated in any other work

known to me."
The passages I have cited will serve to show the spirit in which Darwin
entered upon his geological studies, and the perusal of the following
pages will