“…However, for the inner square this dependence on time is so weak that i.e., for the same initial concentration of one of the precipitating components, the critical concentrations should be reached at the same distances from the middle of the trough, without respect to the initial concentration of the other precipitating component. Film negative of the precipitation of the CuCI2-K2Cr04 system under conditions of two-dimensional double diffusion in a one-cross, according to the schematic representation in Figure 1 Component A, CuCI2; component B, K2Cr04; initial concentrations, 1 mol dm-3; dilution factors, n* = ne = 5; stabilizing medium, 1 % agar; time of diffusion, 90 min; temperature, 20 °C. The precipitate acts as a membrane, permeable in the case of excess of CuCI2.…”