Measuring diffusion coefficients by Taylor's method of hydrodynamic stability

Diffusion coefficients for liquid solutions can be measured using a hydrodynamic stability criterion first derived by G. I. Taylor. This method is used in the present work to determine diffusion coefficients for a range of solutes from small molecules to colloidal particles, at infinite dilution and at finite concentrations. The method is simple and accurate and seems to have wide applicability. Taylor's stability criterion can also be used to establish known, linear concentration gradients of several different solutes in one column of fluid, and one solute can be used to create a desired gradient of a second solute.