Resistance, Hittorf's.
A high resistance, often a megohm, composed of Hittorf's solution, q. v.
It is contained in a vertical glass tube near whose upper and lower ends
are electrodes of metallic cadmium attached to platinum wires. The
cadmium is melted in glass tubes, the platinum wire is inserted into the
melted metal and the tube is broken after all is solid. The resistance
should show no polarization current.