A study has been made of the factors affecting the migration of proteins during electrophoresis on paper strips held between glass plates. A major difficulty in interpreting results is caused by movement of liquid in the paper from anode to cathode, the rate of flow diminishing from the anode end to the cathode end. Even with non-uniform liquid flow of this type it is possible to choose a path such that migration of an ion is linear with respect to both time and potential gradient.

SummaryThe depilatory action of sodium sulphide on sheepskin has been investigated by measuring the pull required to remove wool from skin, the swelling of wool root shafts, and the mechanical strength of wool. The rate of action is augmented by increase in temperature, pH value, and concentration of sulphide in the solution employed up to 1.0M, but is reduced by increase to higher concentrations. The reciprocal action of the hydroxyl and hydrosulphide ions in digesting keratin is explained in Appendix I in terms of the ionization of sulphydryl groups.Solutions of l.OM sodium sulphide, partially oxidized with peroxide and adjusted to pH 12.8, completely loosen wool in 18 hours at 20°C. only if the oxidation-reduction potential is lower than -400 millivolts.Salts of various oxyacids of sulphur are less effective depilatories than sodium sulphide, the activity diminishing with increase in the number of oxygen atoms in the anion and approximately with the heat of formation.Sodium selenide and sodium telluride possess depilatory activity equal to that of sodium sulphide.