sion or series of facts. Each one of these headings is
again enlarged and often transferred before I begin to write in extenso.
As in several of my books facts observed by others have been very
extensively used, and as I have always had several quite distinct
subjects in hand at the same time, I may mention that I keep from thirty
to forty large portfolios, in cabinets with labelled shelves, into which
I can at once put a detached reference or memorandum. I have bought many
books, and at their ends I make an index of all the facts that concern
my work; or, if the book is not my own, write out a separate abstract,
and of such abstracts I have a large drawer full. Before beginning
on any subject I look to all the short indexes and make a general and
classified index, and by taking the one or more proper portfolios I have
all the information collected during my life ready for use.

I have said that in one respect my mind has changed during the last
twenty or thirty years. Up to the age of thirty, or beyond it, poetry
of many kinds, such as the works of Milton, Gray, Byron, Wordsworth,
Coleridge, and Shelley, gave me great pleasure, and even as a schoolboy
I took intense delight in Shakespeare, especially in the historical
plays. I have also said that formerly pictures gave me considerable, and
music very great delight. But now for many years I cannot endure to read
a line of poetry: I have tried lately to read Shakespeare, and found
it so intolerably dull that it nauseated me. I have also almost lost
my taste for pictures or music. Music generally sets me thinking too
energetically on what I have been at work on, instead of giving me
pleasure. I retain some taste for fine scenery, but it does not cause me
the exquisite delight which it formerly did. On the other hand, novels
which are works of the imagination, though not of a very high order,
have been for years a wonderful relief and pleasure to me, and I often
bless all novelists. A surprising number have been read aloud to me, and
I like all if moderately good, and if they do not end unhappily--against
which a law ought to be passed. A novel, according to my taste, does not
come into the first class unless it contains some person whom one can
thoroughly love, and if a pretty woman all the better.

This curious and lamentable loss of the higher aesthetic tastes is all
the odder, as books on history, biographies, and travels (independently
of any scientific facts which th