History
Psoralens have been known since ancient Egypt but have only been available in a chemically synthesized form since the 1970s.
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Famous quotes containing the word history:
“This is the greatest week in the history of the world since the Creation, because as a result of what happened in this week, the world is bigger, infinitely.”
—Richard M. Nixon (1913–1995)
“All history becomes subjective; in other words there is properly no history, only biography.”
—Ralph Waldo Emerson (1803–1882)
“The history of all hitherto existing society is the history of class struggles.”
—Karl Marx (1818–1883)