The photographic news

• Bandzählung: 6.1862
• Erscheinungsdatum: 1862
• Sprache: Englisch
• Signatur: F 135
• Vorlage: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: SLUB Dresden
• Rechtehinweis: Public Domain Mark 1.0
• URN: urn:nbn:de:bsz:14-db-id1780948042-186200003
• PURL: http://digital.slub-dresden.de/id1780948042-18620000
• OAI: oai:de:slub-dresden:db:id-1780948042-18620000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Bemerkung: Seite 1-72 fehlen in der Vorlage. Vorlagebedingter Textverlust.
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

536 THE PHOTOGRAPHIC NEWS. on the same picture will be produced, which may be often used with advantage. In conclusion, I would remind the reader that the end of all fancy printing is to improve the print so that any designs used, must be kept quiet and sub servient. The flat tints should never be made very dark, as it would give a heavy effect to the whole. PHOTOGRAPHIC PRINTING ON WHITE SILK. BY HENRY COOPER, JUN. Since the publication of my last communication, I have printed some photographs on silk, by the aid of the resins used for preparing the paper for the new method of print ing ; and as the results have been much admired, and have excited considerable interest, I do not think a short account of the method used would be uninteresting to your readers; and I should be obliged if you could find space for these remarks in your valuable journal. I have tried several for mulae, and although Iceland moss gave very nice results, I prefer to use a small quantity of a resin to give a surface to the silk, to prevent the image sinking too much into its substance. A great deal depends upon the silk, so that the first point is to procure a suitable kind. It must be rather stout and opaque, and very perfect in the thread. The best French glace answers very well, if it be of really first-rate quality ; but I should think gros de Naples would do better. Ascertain which is the right side, and mark it. As the silk will require to be ironed once or twice during the preparation, some fine flannel must be obtained, and three or four thicknesses laid on a board; this is to form the material to iron upon. If there are any creases in the silk, lay it face downwards, and over the back place a sheet of fine filtering paper, and then iron it until they disappear. Then prepare the following solution:— Pure frankincense ... ... ... 4grs. Mastic 2 grs. or 3 grs. Chloride calcium ... ... ... 15 grs. Spirit 1 oz. Filter before use. Immerse the silk in the same manner as I directed for paper; but pin it up by two corners. To sensitize it, immerse in the silver bath, which should be CO grains to the ounce, and faintly acid. Several pieces of silk may be immersed at the same time, so long as they are put in separately. This will save time, as they must remain in the bath at least a quarter of an hour. Turn the batch over, and remove the pieces singly, and again pin up by two corners. When the silk is quite dry, it is to bo ironed, before exposure in the printing frame, in the same manner as I have described above. If this be neglected, the silk is very apt to cockle, rendering the prints misty in parts. The covering the back with clean filtering paper, both in the ironing and in the pressure frame, must on no account be omitted. Print deeply; wash quickly; and tone in a bath of acetate of soda and chloride of gold, rather strong. Tone to the required depth ; wash icell; and fix in new hypo; this should be also rather strong. Wash very carefully and thoroughly ; taking care that no impurities come near the prints, as the silk is easily soiled whilst wet. If the prints be small and are intended for book-markers, or things of that description, they may be simply dried and ironed; but should they be large, for screens, &c., they must be stretched, whilst wet, over a frame, and left to dry in a state of tension. Although the manipulations are rather tiresome, the photo grapher will be amply repaid by the results. The fruits are brilliant in the extreme ; the shadows are particularly deep and transparent, and every detail in the negative is perfectly rendered on the silk. The uses to which this style of print ing may be put, are almost numberless, and I would recom mend it to the attention of all photographers; hoping that all who try it may succeed. Note ox RESINIZED Paper.—I have recently made some [November 7,1862. improvements in the formula for resinized paper. By the new method, the paper will keep after sensitizing as long as albumenized paper; the prints possess greater transparency in the shadows ; and are free from the granular appearance to which I called attention in my last remarks. Immerse thin Rive (I used a negative paper) in a sufficient quantity of the following solution, which may be filtered through paper: Pure Frankincense ... ... ••• 10 grs. Mastic 8 grs. Chloride of Calcium 15 grs. Spirit ... ... ... ... ... 1 oz. The proofs are easily toned, and any tint may be obtained. The fact that the tone becomes bluer when the print is dry, must not be lost sight of. A slight application of Clausel’s encaustic paste is a wonderful improvement in some cases. By a judicious use of it, some parts of the picture maybe brought out more prominently than others. But I would not advise its use except as a last resource. H. C. • THEORY OF ALKALINE GOLD TONING. BY FRANCIS G. ELIOT. Dear Sir,—Perceiving that you have been for some time endeavouring to work out the faults of the’ alkaline toning bath, and that a correspondent under the title of “ Photo grapher’s Assistant,” has been writing some able articles on this subiect, and has lastly advanced a theory on its supposed nature, I beg to inform you, that having for some time been working in the same direction, I have at length hit upon what I believe will be found to be the correct solution of the difficulty, and if so, will greatly improve our knowledge of this hitherto troublesome part of our manipulation. Your correspondent has very nearly got upon the right track, when he says he believes a decomposition of the gold takes place, but I think he has a little missed the mark iu his explanation ; to go at once to the point then, I believe the gold solutions to exist in four states, and taking the chloride of gold as a simple terchloride, according to the English school of hydrogen being 1, not the Berzelius scale of 0'5, as your correspondent has it, we have, first, Au CL. plus free acid, the state in which the gold is usually sent out, and the state in which it was used by Le Gray and others, . for toning. Secondly, Au Cla. minus free acid, the state in which it exists in a bath in which any quantity, no matter how much, carbonate of soda is thrown in, and in this state a first batch of prints being immediately immersed: its action is as follows: the prints are very much reduced, a false colouring is given, which dissolves off in the hypo. If the prints arc kept long in, to get full toned, a nasty slaty colour is produced, and general mealiness is the result; it is not until the gold is nearly exhausted, that the prints begin to tone properly. Thirdly, Au CL, this is the state in which No. 2 becomes after a number of prints have been toned in it: it also comes by keeping the bath for some time, and also by heating, but it is best produced by adding one equivalent of soda carb, only, to No. 2, and allowing decomposition to proceed as far as it will go. Here we are met with a difficulty, the varying amount of free acid in different samples of chloride of gold. The atomic weight of chloride of gold is 303, and of crystallized carbonate of soda, 144, and the dry, as sold for effervescing draughts, containing 40 per cent, of alkali, about one-third less, so that if my theory is correct, one-third grain to every grain of gold would be enough. That the quantity generally used is more than necessary, is proved by the fact, that Mr. Thomas, the celebrated collodion maker, exhibited at at a meeting of the society, some separate toned prints, with only three-fourths of a grain of carbonate of soda to each grain of gold; probably with any other gold but his own that would completely fail. I believe, however, that the chief failures arc to be attributed to a, perfect decomposition, as far as the soda will allow, not having taken place. "I shall presently indicate a method of doing this quickly, and with certainty. N F< whic is ad vale wher then find ougl state alm< . N first gold unct add stro betv of 1 larg recc tryi fori will into grai pou ten gok mer folk No. incr not to 1 and any N slig and all. witl duc obt: wor ma; onl A : Ne eve dry Hi] ove its oft La wit mo the wh Th resi noi an * nen dou on <