James Henry Eastman, a Detroit inventor who held several patents for violet ray machines, established the RenuLife Electric Co., in Detroit, in 1917. The device was a hand-held Tesla coil with glass tubes to (theoretically) protect the user:
“Treatment with a violet ray machine involved attaching one of a various set of evacuated glass tubes to a handle, holding it to whatever part of your body was troublesome, and then switching it on. This caused a high voltage, high frequency, low electrical current to run through the body. Similar technology is actually still used today in TENS machines that zap low currents into a targeted area of the body to relieve pain through nerve stimulation, though modern machines are safer and their use is monitored by trained professionals who use them only for specific types of pain. A violet ray machine, on the other hand, was capable of creating a powerful electric arc that could cause serious skin burns.”
[History and images found here.]
Tacky Raccoons 