In the theoretical part of this work it is shown that the Lamm´s Differential Equation for polymer solutions can be extended to swollen polymer networks, if the phenomenological equations and the equation for the chemical potential of the polymer component in the network are taken into account. All differences for a transition from a polymer solution to a swollen polymer network can be assigned a "Elastically active coefficient E", which describes a deformation velocity with the same unit as the diffusion coefficient. In the practical part of this thesis some new improvements/developments regarding the Schlieren optical system are introduced and discussed. In the part "Results and Discussion" the results of the centrifugal measurements of gelatine gels are presented and discussed. The following evaluation of the centrifugal runs of polyacrylat gels (chemical networks) and the comparison with the results of the gelatine gels (physical networks) shows clearly that the new theory is suitable to describe the move ment of the polymer component in the network in a centrifugal field quantitatively as well as qualitatively.