After drying, the picture is put upon a marble slab, made very hot, taking care, however, that the print does not become brown by heating. By undergoing this operation of heating, the chromate salt is endowed with the property of readily attracting the printing ink. A piece of unsized paper, rather smaller than the picture, is now moistened, flattened upon a piece of patent plate, and the superfluous water removed by the aid of filter paper. Then the image is floated upon its back for a few seconds upon warm water until the water has moistened through the paper and wetted the coating of starch. The image is then taken out of the water and placed upon the sheet of moist paper lying upon the patent plate; in this position the two surfaces are placed in contact, and covered with a dry sheet of sized paper, the latter being rubbed over in all directions by means of a soft cloth, so that the moisture penetrates uniformly, and the whole becomes firmly adherent to the glass plate. The sheet is then taken away, and the image laid bare. In the meantime a stone is brought, such as lithographers employ, together with printers' ink, and litho. ink which is mixed by means of a little oil varnish.

With this ink, applied to a bit of flannel, a roller covered with fine cloth is coated as uniformly as possible; the roller is then carefully and without pressure rolled over the image, which soon becomes black, and rapidly assumes vigour as the rolling goes on, while the whites still remain perfectly white. The picture is then in a position to be transferred to stone; the application of the ink to the image must not be carried too far. While the paper is yet damp (so that the paste may adhere to the stone), it is laid upon a lithographic stone, and passed in this way through the press. If the paper holds too fast to the stone, so that it cannot be detached, a little damping of the paper soon brings this about. The image is then to be seen clear and sharp upon the stone, and the printing of copies can then be proceeded with in the ordinary manner in any lithographic workroom. The paper employed in the process for the transfer, being unsized, is easily penetrable by water. Portions, however, of the paper, where the light has acted upon the bichromate of potash covering it, do not become moistened.

These parts of the paper, indeed, when heated, will permit any ink to adhere at once.

Unsized paper upon which is formed a print in bichromate of potash, after being heated and moistened with water, behaves, in a word, exactly in the same manner as a lithographic stone; some portions of it attract the ink, while others repel it. Where the light has acted, there the surface becomes hard, and the ink adheres; whereas the other portions yet absorb water, and in this condition repel the ink. If the paper is covered on the image surface with starch, the transfer will have more solidity. ('Photog. Archiv.')

(36) Komaromy, of Budapest, paints a paper with the following solution: - 1 oz. gelatine, 5 oz. glycerine, 1/4 oz. Chinese gelatine, 1 oz. water. The manuscript is written with the following solution: 100 parts water, 10 of chrome alum, 5 of sulphuric acid, 10 of gum arabic. The manuscript is laid on the first paper, and the surface of the latter is thereby rendered incapable of taking up an aniline solution with which the first surface is then flowed. Excess of colour is absorbed with silk paper, and negative impressions are then taken on clean paper.