History
Psoralens have been known since ancient Egypt but have only been available in a chemically synthesized form since the 1970s.
Read more about this topic: PUVA Therapy
Famous quotes containing the word history:
“It’s a very delicate surgical operation—to cut out the heart without killing the patient. The history of our country, however, is a very tough old patient, and we’ll do the best we can.”
—Dudley Nichols, U.S. screenwriter. Jean Renoir. Sorel (Philip Merivale)
“Man watches his history on the screen with apathy and an occasional passing flicker of horror or indignation.”
—Conor Cruise O’Brien (b. 1917)
“A man will not need to study history to find out what is best for his own culture.”
—Henry David Thoreau (1817–1862)