Excerpt from History and Development of the Deposition of Copper Ferrocyanide Membrane by the Electrolytic Method In the original article of Morse and Horn, they state the object they had in mind in the following words: It occurred to the authors that if a solution of copper salt and one of potassium ferrocyanide are separated by a porous wall which is filled with water, and a current is passed from an electrode in the former to another electrode in the latter solution, the copper and the ferrocyanogen ions must meet in the interior of the wall and separate as copper ferrocyanide at all the points of meeting, so that in the end there should be built up a continuous membrane well supported on eitherside by the material of the wall. Such were the first con ceived ideas in the progress of the methods of membrane formation. The first problem which confronted the efi'orts of this early work was a method of effectively removing the air from the porous cups which, in themselves, furnished but a poor means of supporting the copper ferrocyanide mem brane. The purpose of removing the air from the walls of the cell is obviously to overcome the interference in the formation of a sound and homogeneous membrane. The investigators made use of the strong endosmose which ap pears, when a current is passed through a porous wall, sepa rating two liquid substances. The morse-horn method of removing the air from the walls of these porous cups, consisted in the use of a boiled solution of potassium sulphate containing about five-tenths of a gram Of salt in a liter of water. This sulphate solution is placed both in the interior of the porous cup and in the jar in which the cup sits. On passing the current between the electrodes in, the direction of the electrode within, the liquid in the cup rises with a sufficient rapidity to increase with the dilution of the solution and with the intensity of the current. As the liquid is carried along by the electric current, the air is bodily swept along with 'the water to the interior of the cell and thence out of the siphon. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.