Wilhelm Pfeffer

Wilhelm Friedrich Philipp Pfeffer (9 March 1845 – 31 January 1920) was a German botanist and plant physiologist born in Grebenstein.

He studied chemistry and pharmacy at the University of Göttingen,[1] where his instructors included Friedrich Wöhler (1800-1882), William Eduard Weber (1804-1891) and Wilhelm Rudolph Fittig (1835-1910).

In 1877, while researching plant metabolism, Pfeffer developed a semi-porous membrane to study the phenomena of osmosis.

The eponymous "Pfeffer cell" is named for the osmometric device he constructed for determining the osmotic pressure of a solution.

He wanted to extend the chronophotographic experiments of Étienne-Jules Marey (1830-1904) by producing a short film involving the stages of plant growth.