Mercury Photographs

Abstract

AN entirely novel method of photographic printing has just been discovered by M. Merget of Lyons. Although akin in some respects to the daguerreotype process, it differs essentially therefrom in the fact that exposure to light is not necessary to the formation of every separate image. It is difficult indeed just now to apply any distinguishing name to M. Merget's invention, for the methods hitherto discovered—and the number of these has, we all know, increased of late beyond all calculation — are all of them divisible into two very distinct classes. Thus we have those processes broadly termed chemical, in which every print is secured by the aid of light, as for instance, the nitrate of silver and carbon methods; and those again where a matrix, or printing block, having been prepared, the copies are struck off in the ordinary lithographic or printing press; photographs prepared in this latter manner are usually termed photo mechanieal prints. M. Merget's invention partakes singularly enough of the nature of both classes; for while the prints are undoubtedly formed by chemical action, the question of light is of no moment at all, and the manipulations involved are to some extent of a mechanical nature.