Magnetism is one of the manifold forms under which
electricity reveals itself. The ancient vague presentiment of the identity
of electric and magnetic attraction has been verified in our own times.
"When electrum (amber)," says Pliny, in the spirit of the Ionic natural
philosophy of Thales,* is 'animated' by friction and heat, it will attract
bark and dry leaves precisely as the loadstone attracts iron."
[footnote] *Of amber (succinum, glessum) Pliny observes (xxxvii., 3),
"Genera ejus plura. Attritu digitorum accepta caloris anima trahunt in se
paleas ac folia arida quae levia sunt, ac ut magnes lapis ferri ramenta
quoque." (Plato, 'in Timaeo', p. 80. Martin, 'Etude sur le Timee', t. ii.,
p. 343-346. Strabo, xv., p. 703, Casaub,; Clemens Alex., 'Strom.', ii., p.
370, where, singularly enough, a difference is made between [Greek words])
When Thales, in Aristot., 'de Anima', 1, 2, and Hippias, in Diog. Laert.,
i., 24, describe the magnet and amber as possessing a soul, they refer only
to a moving principle.
The same words may be found in the literature of an Asiatic nation, and
occur in a eulogium on the loadstone by the Chinese physicist Kuopho.*
[footnote] *"The magnet attracts iron as amber does the smallest grain of
mustard seed.
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