The history of the discovery and investigation of ascending diffusion and the diffusion aftereffect is described. The role of V. S. Gorskii (1905--1941) in the discovery and study of these effects is discussed. A brief presentation of V. S. Gorskii's biography and the content of his pioneering work (1934--1935) on this problem is given. Diffusion inelasticity and equilibrium segregation are discussed within the framework of V. S. Gorskii's ideas. Kinetic segregation, which appears in situations when an alloy contains an active source of vacancies and the diffusion of the components of the alloy is directly proportional to the different partial diffusion coefficients is discussed in the concluding section.