  Many studies on microscopic systems deal with Brownian particles embedded in
media whose densities are different from that of the particles, causing them
either to sink or float. The proximity to a wall modifies the friction force
the particle experiences, being, instead of the Stokes force assumed by
Einstein and Langevin, a function of the separation distance, as described by
Faxen. In this work we present a thorough analysis of bidimensional Brownian
motion using monodisperse suspensions of latex beads with controlled
temperatures. By means of Langevin's model and Faxen's correction, we calculate
the mean separation distance between the spheres and the bottom of the
confining vessel.
