The examples that I have the honor of presenting are the first results of my extensive research on the manner of fixing the image of objects by the action of light.
Light acts chemically upon bodies. It is absorbed, it combines with them, and communicates new properties. Such, in a few words, is the principle of the discovery.
Numerous experiments made by the author prove that light cannot fall upon a body without leaving traces of decomposition on the surface upon which it impinges.