A Qualitative Approach to Coupled Diffusion with Reference to Self- and Tracer-Diffusion in Soil

The processes of self- and tracer-diffusion have been examined from a kinetic (qualitative) standpoint. An attempt has been made to explain the cases of positive and adverse coupling. The findings have been critically compared with those of Gosling's treatment of the subject based on irreversible thermodynamics. The cases of self- and tracer-diffusion in soil, in particular, have been referred to, and the validity of the predictions regarding ionic (background) movement in tracer-diffusion has been put to an experimental test involving diffusion in sand.