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:
“The history of American politics is littered with bodies of people who took so pure a position that they had no clout at all.”
—Ben C. Bradlee (b. 1921)
“What would we not give for some great poem to read now, which would be in harmony with the scenery,—for if men read aright, methinks they would never read anything but poems. No history nor philosophy can supply their place.”
—Henry David Thoreau (1817–1862)
“It is my conviction that women are the natural orators of the race.”
—Eliza Archard Connor, U.S. suffragist. As quoted in History of Woman Suffrage, vol. 4, ch. 9, by Susan B. Anthony and Ida Husted Harper (1902)