the SCEPSIS SCIENTIFICA, published in 1665, Joseph Glanvil wrote, 'to
confer at the distance of the Indies by sympathetic conveyances may be
as usual to future times as to us in literary correspondence.' [The
Rosicrucians also believed that if two persons transplanted pieces of
their flesh into each other, and tattooed the grafts with letters, a
sympathetic telegraph could be established by pricking the letters.]

Dr. Gilbert, physician to Queen Elizabeth, by his systematic researches,
discovered the magnetism of the earth, and laid the foundations of the
modern science of electricity and magnetism. Otto von Guericke,
burgomaster of Magdeburg, invented the electrical machine for generating
large quantities of the electric fire. Stephen Gray, a pensioner of the
Charterhouse, conveyed the fire to a distance along a line of pack
thread, and showed that some bodies conducted electricity, while others
insulated it. Dufay proved that there were two qualities of
electricity, now called positive and negative, and that each kind
repelled the like, but attracted the unlike. Von Kleist, a cathedral
dean of Kamm, in Pomerania, or at all events Cuneus, a burgher, and
Muschenbroek, a professor of Leyden, discovered the Leyden jar for
holding a charge of electricity; and Franklin demonstrated the identity
of electricity and lightning.

The charge from a Leyden jar was frequently sent through a chain of
persons clasping hands, or a length of wire with the earth as part of
the circuit. This experiment was made by Joseph Franz, of Vienna, in
1746, and Dr. Watson, of London, in 1747; while Franklin ignited spirits
by a spark which had been sent across the Schuylkill river by the same
means. But none of these men seem to have grasped the idea of employing
the fleet fire as a telegraph.