"Carbon Arc" lamps were the first commercial electric light source, and are still considered the most efficient source of true white light.
The are virtually a sustained welding arc in open air that produces an intense blinding light across the entire visible spectrum.

"Ultra-Violet Quartz Irradiation" lamps were early forms of sunlamps with intense germicidal properties.  Most also generated copious amounts of ozone in addition to ultraviolet radiation.   

"Phototherapy" was a field that used light and UV radiation to treat diseases.  It was pioneered by Danish physician Niels Finsen in his groundbreaking work with lupus cases.  Over the years it was unfortunately reduced to various shades of quackery with semi-bogus (but amusing) "colored light" therapy machines.



Click here for the Phototherapy Photo Gallery