Magneto-electric machine, late 19th century.
© Science Museum / Science & Society Picture Library
In the late 18th century, Luigi Galvani (1737-1798) discovered 'animal electricity'. Nerves and muscles in animals function by tiny electrical currents, and can be stimulated by outside electricity. Soon electrical treatments were in great fashion, and were believed to be able to cure all manner of complaints, from gout to paralysis.