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226 THE PHOTOGRAPHIC NEWS. The improved method is based on the property, as yet practically unapplied, of gelatine, when prepared in a certain Way, not swelling from moisture in those parts in which it has been acted on by light, and not melting when any hot liquid substances are poured on it, such as tallow, compounds of gutta percha with wax, or any other substances capable of serving, whether directly or indirectly, the purpose of a matrix for obtaining a copper galvano-plastic plate. The method includes (a.) an application to litho and typography, (b.) an application to chromotype, and (c.) to printing from nature by means of gelatinous ink. The first part of the method consists of the following ten operations:—1. Covering plate glass with a layer of gelatine. 2. Drying the gelatine layer. 3. Preparing the gelatine layer; i.e., making it sensitive to light and incapable of dissolving when the gutta-percha is poured on it. 4. Exposing it to the light under a photographic negative or positive taken from an original, made with pen or pencil, in those cases when the drawing is to be on a reduced scale. When, however, the drawing is to be of the same dimensions as the original, I employ the original itself, if on thin paper. 5. Revealing the drawing by means of a moist surface, glue or gelatine. 6. Im pressing the drawing on gutta-percha. 7. Increasing the relief of the gutta-percha plate by hand. 8. Obtaining the copper matrix. Operations 7 and 8 are omitted in those cases when, in order to obtain the printing surface, I make use of the photographic positive, or of the original executed on thin paper. 9. Obtaining the copper plate or printing surface in relief (cliche). 16. Increasing the relief of the copper plate or the cliche by corroding the ground. The method as applied to chromotype consists of the follow ing operations:—1. Obtaining an outline plate in relief (cliche) from an outline original. 2. Printing on paper from the outline cliche by means of a blue or other non-photogenic colour. 3. Preparing the originals for the simple colour contained in the drawing. And 4. Preparing, according to the above described method, cliches for printing the simple colours separately. The Method as applied to Lithogbaphy and Typogeapiiy. 1. The Gelatine Layer.—I take 1 part of the best gelatine and wet it in 10 to 15 parts of water of the usual temperature, and at the expiration of a quarter of an hour I warm the water to 70° R. When the gelatine has cooled sufficiently, I add strong liquid ammonia, and cool it to a temperature of 30° R., and then pour a thin layer of gelatine on glass laid horizontally. The use of ammonia is indispensable in order to avoid a film when the drying of the glasses is produced very slowly, and also for the more convenient pouring of the gelatine on the glass. 2. The drying of the gelatine layer is performed in a dry air at the usual temperature, and is efected in one night. 3. Preparing the Gelatine.—In order to render the gelatine sensitive to light, and to make it incapable of melting when hot gutta-percha is poured on it, I wash the gelatine layer in a solution consisting of 1 part of bichromate of potass or ammonia, 3 parts of alum, and all this is dissolved in sufficient quantity of water. Previous to use the entire compound is diluted with 20 or 10 parts of water, and the gelatine layer is wetted during 1 or 2 minutes. 4. Exposing it to the Light.—The gelatine layer prepared in the above way is slowly dried in a dark room, and then, in order to obtain a printing surface, is exposed to the light under the original made on thin white paper, or under the photo graphic positive or negative, the use of the positive or the negative being dependent upon the circumstance that in order to obtain a copper plate the light must act on the drawing itself, and in order to obtain a cliche on the ground of the drawing. Care must be observed that there should be no dust between the gelatine and collodion layers, and after both the glasses have been placed in the printing frame and subjected to firm and equal pressure they are exposed to the light from one to twenty-five minutes, according to the strength of the light and the quality of the photographic glass. 5. Revealing the Drawing.—Those portions of the prepared gelatine which have been exposed to the action of light lose their capability of swelling from moisture, while the remaining portions preserve that capability. Therefore by dipping the glass with the gelatine layer in water it is possible to reveal the drawing, but by such means it is impossible to obtain any [May 7, 1869. thing fit for use, as the gelatine swells more in those parts where the drops of water adhere than in other places. This difficulty is completely obviated by pouring on the prepared layer of gelatine a thick layer of glue or gelatine simply dissolved in hot water and cooled to a temperature of 33° R., taking 1 ounce of gelatine to 4 ounces of water. When the gelatine thus poured on has cooled it can be easily taken of the prepared layer, when an excellent drawing is obtained, either in relief or hollowed out, according to which portion of the gelatine has swelled, i.e., the one corresponding to the ground or to the drawing. Independently of this action, the moist surface imbibes the bichromate of potass in the parts not acted on by light, so that after the drawing has appeared the glass may be kept in the light, and whenever a moist layer is poured on it the drawing will be revealed, or, in other words, the glass may serve several times for obtaining the gutta-percba plate. 6. Impressing or Transferring the Drawing on Gutta-percha. —As soon as the moist surface is removed the following com pound is to be poured on the glass, viz., 4 parts of wax, 1 part gutta-percha, and 1 or 3 wine glasses of oil. This is the most important point in the method. No one engaged in gelatine methods has been able to render the gelatine at the same time capable of swelling and incapable of melting from hot sub stances (and to make immediate use of the relief of the gela tine layer is impossible, as it quickly disappears entirely). This is why no one has practically availed himself of the non swelling of gelatine, but only of its indissolubility in water after the action of light. 7. Increasing the Relief of the Gutta-percha Plate.—The relief obtained on the gutta-percha is not sufficient to admit of its being applied to the printing-press and to chromotype pur poses ; I therefore first hollow out by hand those portions in the gutta-percha which correspond to the large white spaces in the drawing. 8. Obtaining the Copper Matrix.—I then carefully cover ths gutta-percha with blacklead, and plunge it into a copper bath, to obtain the copper matrix ; and when the 7 and 8 operations are omitted, I obtain, not a matrix, but directly a copper plate or a cliche. 9. Obtaining Copper Plates and Cliches.—After having covered the copper matrix with turpentine and allowing it to evaporate, I slightly cover the copper matrix with blacklead, and again plunge it into the bath, in order to obtain the copper plate or the cliche. When the copper has become deposited in a sufficiently thick layer, I detatch the plate from the matrix. In this state the cliche is still unadapted to typography, it being necessary somewhat to raise the relief. 10. Increasing the Relief by Corrosion.—For this purpose the entire plate is covered with asphalte varnish, or any other var nish non-conductible to electricity. I then clean the varnish with charcoal from the raised drawing, leaving it on the ground. The drawing is then gilt, silvered, or is covered with other suit able substance; the varnish is washed off with benzine or some other suitable substance, and the copper ground is corroded with the aid of the galvinism, nitric acid, or any other acid which does not act on the layer preserving the drawing. The cliche is then mounted in the usual way. The Method as Applied to CIROMOTYPE. 1. From a coloured original an outline drawing is prepared, and from it, by the above-described method, an outline cliche is made. 2. From this outline cliche an impression is taken on paper in blue or other non-photogenic colour. 3. On each such impression the portions corresponding to one of the several simple colours of the original are covered with indian ink, and thus originals are obtained consisting of spots. 4. From which cliches are made separately for each simple colour. I consider it necessary to add, that the above-described method is quite original, although other gelatine methods are in existence. In the process (a.) the operations marked Nos. 1, 3, 5, 7, 101 and the entire method of chromotype, have nothing similar in existing methods. If the substances entering into the solution in process No. 3 be taken in not suitable proportions, if tho drawing be not revealed in tho way described in No. 6, if tbs drawing be received on any other material but giease and gutta-percha as in No. 6, then tho entire process not only loses its adaptability to typography, but becomes perfectly useless for practical purposes.