an lakes; for Humboldt states that some of
them throw up quantities of fish. The author acknowledges, however, that
the hypothesis of the nucleus of the globe being composed of matter
liquefied by heat, offers a still more simple solution of the phenomena
of volcanic fires."[6]

We have hitherto spoken of Sir Humphry Davy as a philosopher. He was,
however, in every respect, an accomplished scholar, and was well
acquainted with foreign languages. He always retained a strong taste for
literary pleasures; and when his continued illness retarded his
scientific pursuits, he made literature his recreation. In this manner he
wrote _Salmonia: or Days of Fly-fishing_, in a series of conversations,
we gather from the Preface:--"These pages formed the occupation of the
Author during several months of severe and dangerous illness, when he was
wholly incapable of attending to more useful studies, or of following
more serious pursuits. They formed his amusement in many hours, which
otherwise would have been unoccupied and tedious." "The conversational
and discursive style were chosen as best suited to the state of the
health of the author, who was incapable of considerable efforts and long
continued exertion." The volume is dedicated to Dr. Babington, "in
remembrance of some delightful days passed in his society, and in
gratitude for an uninterrupted friendship of quarter of a century:" and
the likeness of one of the characters in the conversations to that
estimable physician abovenamed, has been considered well drawn, and
easily recognisable by those who enjoy his acquaintance.

The philosophical works of Sir Humphry Davy are written in a clear and
perspicuous style, by which means he has contributed more to the
diffusion of scientific knowledge than any other writer of his time. His
three principal works, "Chemical and Philosophical Researches," "Elements
of Chemical Philosophy," and "Elements of Agricultural Chemistry," are in
a popular and familiar style, and the two last are excellently adapted
for elementary study. His numerous pamphlets and contributions to the
Transactions of the Royal Society have the same rare merit of conveying
experimental knowledge in the most attractive form, and thus reducing
abstract theory to the practice and purposes of life and society. The
results of his investigations and experiments were not therefore pent up
in the laboratory or lecture-room where they were made, but by this
valuable mode of c