PbS holds the honor of being the first reported compound to be deposited by CD. In 1869, Puscher described a “new and cheap process, without using dyes, to coat various metals with splendid lustrous colors” [1]. This involved deposition from a thiosulphate solution of lead acetate (and also, in the same paper, from Cu and Sb salts to give presumably corresponding sulphides). These shiny, colored coatings prompted further studies in this process, both to expand the process to other metal sulphides and to understand the process. These studies are discussed in Section 5.2.1.