Photography on Copper

Abstract

DURING a metallographic examination of some copper alloys it was observed that certain etching reagents produced a surface which was light sensitive, to such a degree that the illuminated area of the specimen turned black during a few seconds' examination under the microscope. The phenomenon has been investigated, and found to depend upon the well-known light-sensitivity of cuprous chloride. The process affords a simple and rapid method of obtaining a sharp photographic image on the surface of plates of copper and copper alloys, including white alloys like German silver. It appears, however, to have escaped observation, and a brief description may therefore be of interest. It seems possible that the process may have some technical application, although I do not know of any, and I should be glad to give further information to anyone interested.