honoured me.

And, lastly, let me say that I reprint the review of "The Origin of
Species" simply because it has been cited as mine by a late President of
the Geological Society. If you find its phraseology, in some places, to
be more vigorous than seems needful, recollect that it was written in
the heat of our first battles over the Novum Organon of biology; that we
were all ten years younger in those days; and last, but not least, that
it was not published until it had been submitted to the revision of a
friend for whose judgment I had then, as I have now, the greatest
respect.

Ever, my dear TYNDALL,

Yours very faithfully,

T.H. HUXLEY

LONDON, _June 1870_.

CONTENTS.

I.
PAGE
ON THE ADVISABLENESS OF IMPROVING NATURAL KNOWLEDGE.
(A Lay Sermon delivered in St. Martin's Hall, on the evening
of Sunday, the 7th of January, 1866, and subsequently published
in the _Fortnightly Review_) 3

II.

EMANCIPATION--BLACK AND WHITE.
(The _Reader_, May 20th, 1865) 23

III.

A LIBERAL EDUCATION: AND WHERE TO FIND IT. (An Address
to the South London Working Men's College, delivered on the
4th of January, 1868, and subsequently published in _Macmillan's
Magazine_) 31

IV.

SCIENTIFIC EDUCATION: NOTES OF AN AFTER-DINNER SPEECH. (Delivered
before the Liverpool Philomathic Society in April 1869,
and subsequently published in _Macmillan's Magazine_) 60

V.

ON THE EDUCATIONAL VALUE OF THE NATURAL HISTORY SCIENCES.
(An Address delivered at St. Martin's Hall, on the 22d July,
1854, and published as a pamphlet in that year) 80

VI.

ON THE STUDY OF ZOOLOGY. (A Lecture delivered at the South
Kensington Museum, in 1861, and subsequently published by the
Department of Science and Art) 104

VII.

ON THE PHYSICAL BASIS OF LIFE. (A Lay Sermon delivered in
Edinburgh, on Sunday, the 8th of November, 1868, at the request
of the late Rev. James Cranbrook; subsequently published in the
_Fortnightly Review_) 132

VIII.

THE SCIENTIFIC ASPECTS OF POSITIVISM. (A Reply to Mr. Congreve's
Attack upon the preceding Paper. Published in the _Fortnightly
Review._ 1869)