From the time of the ancients, electricity was always an astonishing and almost miraculous phenomenon. Any number of superstitions and myths attended the natural occurrence of lightening, and early Vikings believed that this phenomenon originated from a magic hammer thrown to earth by Thor, the god of thunder. In the latter part of the eighteenth century, Benjamin Franklin established the relationship between lightening and electricity with his famous kite experiment.
Nikola Tesla was one of the greatest inventors of modern times, and his early landmark discoveries include the radio and alternating current. He was able to transform household electricity into high voltage, high frequency, low amperage energy. His development of high frequency current in 1891 was picked up by the medical community as manufacturers incorporated this discovery in a variety of medial devices.
Electricity could be produced in a number of ways, and entrepreneurs were eager to capitalize on a growing and unregulated industry. Faradic, galvanic, wet and dry cell batteries, and static electricity produced direct current for home devices before indirect current was available to power larger machines in doctors’ offices.