CHLORINE GAS AND SODA BY THE ELECTROLYTIC PROCESS. The decomposition of a solution of common salt, and its conversion into chlorine gas and caustic soda solution by means of an electric current, has long been a study with electro-chemists. Experimentally it has often been effected, but so far as we are aware, the success of this method of production has never until now been demonstrated on a sound commercial basis. The solution of this important industrial problem is due to Mr. James Greenwood, who has been engaged in the development of electro-chemical processes for many years. The outcome of this is that Mr. Greenwood has now perfected an electrolytic process for the direct production of caustic soda and chlorine, as well as other chemical products, the operation of which we recently inspected at Phoenix Wharf, Battersea, London. One of the special features in connection with Mr. Greenwood's new departure is the novel and ingenious method by which the electrolyzed products are separated, and their recombination rendered impossible. This object is attained by the use of a specially constructed diaphragm which is composed of a series of V-shaped glass troughs, fitted in a frame within each other with a small space between them, which is lightly packed with asbestos fiber. Another important feature of the apparatus is a compound anode which consists of carbon plates, with a metal core to increase the conductivity. The anode is treated in a special manner so as to render it non-porous and impervious to attack by the nascent chlorine evolved on its surface. No anode appears ever to have been invented that is at all suitable for working on a large scale, and the successful introduction of this compound anode, therefore, constitutes a marked advance in the apparatus used in electrolytic methods of production.