Lippmann made use of this phenomenon by projecting an image onto a special photographic plate capable of recording detail smaller than the wavelengths of visible light. The light passed through the supporting glass sheet into a very thin and nearly transparent photographic emulsion containing submicroscopically small silver halide grains. A temporary mirror of liquid mercury in intimate contact reflected the light back through the emulsion, creating standing waves whose nodes had little effect while their antinodes created a latent image. After development, the result was a structure of laminae, distinct parallel layers composed of submicroscopic metallic silver grains, which was a permanent record of the standing waves. In each part of the image, the spacing of the laminae corresponded to the half-wavelengths of the light photographed.