The present paper deals with the sedimentation of a liquid monodisperse system to define the physical parameters-size, volume, and density-of a single particle of the disperse phase in this system. The proposed physical and mathematical model is based on the use of the barycentric method by which the displacement of the mass center of the liquid disperse system is measured when it has reached the boundary, maximum sedimentation. Spherical form of the particles of the disperse phase is assumed as well as the most compact packing of the spheres in a state of maximum sedimentation at a constant temperature. An example of magnetic suspension of cobalt particles and water is discussed.