This vague presentiment of the ancients has been verified in our own
times. “When electrum (amber),” says Pliny, “is animated by friction
and heat, it will attract bark and dry leaves precisely as the
loadstone attracts iron.” 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 Knopho, in the fourth century: “The magnet attracts
iron as amber does the smallest grain of mustard-seed. It is like
a breath of wind, which mysteriously penetrates through both, and
communicates itself with the rapidity of an arrow.”
Humboldt observed with astonishment on the woody banks of the
Orinoco, in the sports of the natives, that the excitement of
electricity by friction was known to these savage races. Children
may be seen to rub the dry, flat, and shining seeds or husks of a
trailing plant until they are able to attract threads of cotton
and pieces of bamboo-cane. What a chasm divides the electric
pastime of these naked copper-coloured Indians from the discovery
of a metallic conductor discharging its electric shocks, or a
pile formed of many chemically-decomposing substances, or a
light-engendering magnetic apparatus! In such a chasm lie buried
thousands of years, that compose the history of the intellectual
development of mankind.--_Humboldt’s Cosmos_, vol. i.