ng the character and cause of the
former. Combining duly the two factors, all the previous
irregularities disappeared, every result obtained receiving the
fullest explanation. On studying the account of this masterly
investigation, the words wherewith Pasteur himself feelingly alludes
to the difficulties and dangers of the experimenter's art came home to
me with especial force: 'J'ai tant de fois eprouve que dans cet art
difficile de l'experimentation les plus habiles bronchent a chaque
pas, et que l'interpretation des faits nest pas moins perilleuse.'
[Footnote: Comptes-Rendus,' lxxxiii. p. 177.]

********************

XIV SCIENCE AND MAN.

[Footnote: Presidential Address, delivered before the Birmingham and
Midland Institute, October 1877; with additions.]

A MAGNET attracts iron; but when we analyse the effect we learn that
the metal is not only attracted but repelled, the final approach to
the magnet being due to the difference of two unequal and opposing
forces. Social progress is for the most part typified by this duplex
or polar action. As a general rule, every advance is balanced by a
partial retreat, every amelioration is associated more or less with
deterioration. No great mechanical improvement, for example, is
introduced for the benefit of society at large that does not bear
hardly upon individuals. Science, like other things, is subject to
the operation of this polar law, what is good for it under one aspect
being bad for it under another.

Science demands above all things personal concentration. Its home is
the study of the mathematician, the quiet laboratory of the
experimenter, and the cabinet of the meditative observer of nature.
Different atmospheres are required by the man of science, as such, and
the man of action. Thus the facilities of social and international
intercourse, the railway, the telegraph, and the post-office, which
are such undoubted boons to the man of action, react to some extent
injuriously on the man of science. Their tendency is to break up that
concentrativeness which, as I have said, is an absolute necessity to
the scientific investigator.

The men who have most profoundly influenced the world from the
scientific side have habitually sought isolation. Faraday, at a
certain period of his career, formally renounced dining out. Darwin
lives apart from the bustle of the world in his quiet home in Kent.
Mayer and Joule dealt in unobtrusive retirement with