For casting iron or steel plates with nearly pure lead, the material to be treated is subjected to a series of five baths. The first is in a pickle, through which a weak current of electricity is passed. This bath removes the scales from the surface of the metal, and the electricity is said to greatly expedite matters. The second bath is in lime water, which neutralizes the acid. Then comes the bath in clear water. The fourth bath is in a neutral solution of zinc and stannic chlorides. The drying process, which follows, leaves on the surface of the plates a deposit of the mixed metallic chlorides, which protects the plates from oxidation. The next process consists in passing the plates through a bath of molten deal, and when taken from here the metal is found to be coated with an adherent layer of lead, which, though thin, is uniformly spread. It is said this process has no decreasing effect on the ductility or strength of the iron, and that a plate may be bent, closed and opened again without cracking the coating.