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)
“The history of persecution is a history of endeavors to cheat nature, to make water run up hill, to twist a rope of sand.”
—Ralph Waldo Emerson (1803–1882)
“Literary works cannot be taken over like factories, or literary forms of expression like industrial methods. Realist writing, of which history offers many widely varying examples, is likewise conditioned by the question of how, when and for what class it is made use of.”
—Bertolt Brecht (1898–1956)