When colloidal solutions are viewed under
a powerful ultra microscope, the colloidal particles appear to be in a state of continuous zig-zag motion all over the field of view. This motion was first observed by the British botanist, Robert Brown, and is known as Brownian movement.
This motion is independent of the nature of the colloid but depends on the size of the particles and viscosity of the solution - smaller the size and lesser the viscosity faster is the motion.
