An Efficient Electro-Ultrafilter

Four rubber-stoppered alundum thimbles (6406 RA 360) were coated with a 10 per cent solution of parlodion in glacial acetic acid, utilizing a procedure similar to that described by Seibert (1928). The washed, coated thimbles were attached by short lengths of pressure tubing to a glass manifold and lowered into a container composed of 4 glas cylinders somewhat larger in diameter than the thimbles. The former were joined to each other by short lengths of Tygon tubing, 2 diagonal cylinders being connected, in addition, through a central 2-armed well as illustrated in figure 1. Each stopper contained, in addition to the glas tube connecting the thimbles to the manifold, a smaller peripheral tube leading to the bottom of the thimble through which distilled water was circulated around the electrodes. The anode may be an inexpensive pure carbon rod such as is used in a spectroscope, or platinum foil or gauze; 100-mesh brass strainer cloth serves for the cathodes. In operation, the coated thimbles are lowered into the container and the distilled water tubes connected through a small 4-way manifold to a flask of distilled