The Columbia Encyclopedia, Sixth Edition. 2001-07.
Pfeffer, Wilhelm
(vl´hlm pf´fr) (KEY) , 18451920, German plant physiologist. He was professor of botany successively at the universities of Bonn, Basel, Tübingen, and Leipzig (from 1887). With Julius von Sachs, he was a leader in systematizing the fundamentals of plant physiology. Pfeffers experiments in osmotic pressure were fundamental to modern physical chemistry. He wrote a standard work, Physiology of Plants (1881, tr. 19001906).