Finsen Light Cure, invented by Prof. Niels R. Finsen of Copenhagen (died Sept. 24, 1904), is used for the cure of lupus, acne, erisypelas, and similar eruptions, and in combination with X-rays for deep-seated cancers. The Finsen Lamp consists of a powerful electric light focussing through telescopes of colored glass on the diseased surfaces requiring treatment.

Entry from Everybody's Cyclopedia, 1912.