The vibratory movement of microscopic particles of both organic and inorganic substances when suspended in water or other fluids. The movement is the result of the impact of the molecules of the fluid surrounding the particles. This phenomenon was first described by Robert Brown in 1827.
The oscillatory movement of small bodies suspended in fluid, due to molecular bombardment. Unlike bacterial motility. Brownian movement results in no change of position of a particle or organisms seen in a microscopical field.
The oscillatory movement of particles resulting from chance bombardment by other particles.