Some experimental results (1) show that hydrodynamical
The current passage through a binary electrolyte solution conflows with periodical structure result in the region close to tained in a plane-parallel cell is considered. The cell is formed by the limiting current regime. It is shown in (1) that gravitation two identically ideal selective ion-exchange membranes. Nonethemechanisms are not responsible for this type of convection. less, the solution of the problem can also be employed for a cell One of the possible alternative mechanisms can be associated made by two uniformly reversible electrodes. Using the correwith electrokinetic phenomena (electro-and capillary osmosponding boundary conditions it is taken into account that the sis) which can occur when tangential gradients of the elecsolution can be involved in an electro-and capillary osmotic sliptrolyte concentration or of the electric potential appear in ping at the membrane (electrode)/solution interface provided the the solution regime adjacent to the interfaces. It is obvious tangential gradients of the electrolyte concentration and/or the potential are close to the interface. The analysis of the stability of that gradients do not exist in the plane-parallel cell with the well-known one-dimensional solution corresponding to linear ''one-dimensional'' distributions of electric field and elecconcentration distribution in the cell is carried out. The analysis trolyte concentration. However, such gradients caused by shows that the slipping gives rise to a hydrodynamic instability of ''three-dimensional'' periodically structured flows can crethe one-dimensional solution when coions have sufficiently low ate electro-and capillary osmotic slipping of the solution diffusion coefficients in the order of about 10 06 cm 2 s 01 . Under near to the interfaces thereby supporting the flows and themthis condition convective flows with periodical structure may arise selves during a period of time. Such a situation can take when current approaches the limiting value.