Protoplasm of living cell is in from of a colloidal suspension or colloidal system colloidal solutions age those solutions in which the solute particles neither broken into molecules or ions nor the solute particles neither broken into molecules or ions not settled down even after longer period and particles are in dispersed phase. This is a heterogeneous and stable system exhibit the properties like-filterability, adsorption and increased surface area. Tyndall effect coagulation and Brownian movement.

Among above properties of colloids, Brownian movement is a striking feature of colloidal particles. The suspended particles in colloids are in a continuous and rapid motion called as Brownian motion as the phenomenon was detected by the Robert brown who observed the movement of pollen grains in water with the help of a microscope.

Brownian movement in a colloidal solution results due to an unequal bombardment of the particles of dispersed phase by the molecules of the dispersion medium. With an increase in temperature the kinetic energy and activity of the molecules of the dispersion medium increases which results in increased. Brownian movement.

But the amplitude of Brownian movement becomes lesser with an increase in the size of the solute particle becomes lesser with an increase in the size of the solute particle because the chances of its unequal bombardment gradually diminishes. In more viscous colloidal solution also the Brownian movement become move sluggish. Usually the phenomenon of Brownian movement is more clearly exhibited by the micelles of hydrophobic sol than those of hydrophilic sols.