These various alloys, as well as the _phosphorus bronze_, of which we make no mention here, are at present very largely used in the manufacture of technical machines, as well as for supports, valves, stuffing-boxes, screws, bolts, etc., which require the properties of resistance and durability. They vastly surpass in these qualities the brass and like compounds which have been used hitherto for these purposes.--_Bull. Soc. Chim., Paris_, xxxvi. p. 184. * * * * * THE ECONOMICAL WASHING OF COAL GAS AND SMOKE. In a recent number of the _Journal des Usines a Gaz_ appears a note by M. Chevalet, on the chemical and physical purification of gas, which was one of the papers submitted to the Societe Technique de l'Industrie du Gaz en France at the last ordinary meeting. This communication is noticeable, apart from the author's conclusions, for the fact that the processes described were not designed originally for use in gas manufacture, but were first used to purify, or rather to remove the ammonia which is to be found in all factory chimneys, and especially in certain manufactories of bone-black, and in spirit distilleries. It is because of the success which attended M. Chevalet's treatment of factory smoke that he turned his attention to coal gas. The communication in which M. Chevalet's method is described deals first with chimney gases, in order to show the difficulties of the first class of work done by the author's process. Like coal gas, chimney gases contain in suspension solid particles, such as soot and ashes. Before washing these gases in a bath of sulphuric acid, in order to retain the ammonia, there were two problems to be solved. It was first of all necessary to cool the gases down to a point which should not exceed the boiling-point of the acid employed in washing; and then to remove the solid particles which would otherwise foul the acid. In carrying out this mechanical purification it was impossible, for two reasons, to make use of apparatus of the kind used in gas works; the first obstacle was the presence of solid particles carried forward by the gaseous currents, and the other difficulty was the volume of gas to be dealt with. In the example to which the author's attention was directed he had to purify 600 cubic meters of chimney gas per minute, or 36,000 cubic meters per hour, while the gas escaped from the flues at a temperature of from 400 deg. to 500 deg. C. (752 deg. to 932 deg. Fahr.), and a large quantity of cinders had frequently to be removed from the main chimney flues. After many trials a simple appliance was constructed which successfully cooled the gases and freed them from ashes. This consisted of a vertical screen, with bars three mm. apart, set in water. This screen divided the gases into thin sheets before traversing the water, and by thus washing and evaporating the water the gases were cooled, and threw down the soot