1871, for Scottish scientist Dr. Robert Brown (1773-1858), who first described it.
Brownian movement (brŏu'nē-ən)
The random movement of microscopic particles suspended in a liquid or gas, caused by collisions with molecules of the surrounding medium. Also called Brownian motion, molecular movement, pedesis.
The random movement of microscopic particles suspended in a liquid or gas, caused by collisions between these particles and the molecules of the liquid or gas. This movement is named for its identifier, Scottish botanist Robert Brown (1773-1858). See also kinetic theory.
Note: Brownian motion was first explained by the twentieth-century physicist Albert Einstein, who considered it direct proof of the existence of atoms.