Mix half an ounce of nitric acid, six drams of muriatic acid, and
two ounces of water; pour the mixture upon a piece of tin plate
previously made hot, and, after washing it in the mixture, it will
bear a beautiful crystalline surface, in feathery forms. This is the
celebrated _moirée metallique_, and, when varnished, is made into
ornamental boxes, &c. The figures will vary according to the degree of
heat previously given to the metal.