er by a magnet. Brugmans had shown that bismuth
repelled a magnetic needle. Here he stopped. Le Bailliff proved that
antimony did the same. Here he stopped. Seebeck, Becquerel, and
others, also touched the discovery. These fragmentary gleams excited
a momentary curiosity and were almost forgotten, when Faraday
independently alighted on the same facts; and, instead of stopping,
made them the inlets to a new and vast region of research. The value
of a discovery is to be measured by the intellectual action it calls
forth; and it was Faraday's good fortune to strike such lodes of
scientific truth as give occupation to some of the best intellects of
our age.

The salient quality of Faraday's scientific character reveals itself
from beginning to end of these volumes; a union of ardour and
patience--the one prompting the attack, the other holding him on to
it, till defeat was final or victory assured. Certainty in one sense
or the other was necessary to his peace of mind. The right method of
investigation is perhaps incommunicable; it depends on the individual
rather than on the system, and the mark is missed when Faraday's
researches are pointed to as merely illustrative of the power of the
inductive philosophy. The brain may be filled with that philosophy;
but without the energy and insight which this man possessed, and which
with him were personal and distinctive, we should never rise to the
level of his achievements. His power is that of individual genius,
rather than of philosophic method; the energy of a strong soul
expressing itself after its own fashion, and acknowledging no mediator
between it and Nature.

The second volume of the 'Life and Letters,' like the first, is a
historic treasury as regards Faraday's work and character, and his
scientific and social relations. It contains letters from Humboldt,
Herschel, Hachette, De la Rive, Dumas, Liebig, Melloni, Becquerel,
Oersted, Plucker, Du Bois Reymond, Lord Melbourne, Prince Louis
Napoleon, and many other distinguished men. I notice with particular
pleasure a letter from Sir John Herschel, in reply to a sealed packet
addressed to him by Faraday, but which he had permission to open if he
pleased. The packet referred to one of the many unfulfilled hopes
which spring up in the minds of fertile investigators:

'Go on and prosper, "from strength to strength," like a victor
marching with assured step to further conquests; and be certain that
no voice will