The photographic news

• Bandzählung: 13.1869
• Erscheinungsdatum: 1869
• 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-id1780948042-186900000
• PURL: http://digital.slub-dresden.de/id1780948042-18690000
• OAI: oai:de:slub-dresden:db:id-1780948042-18690000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Bemerkung: Heft 545 (S. 73-84), Heft 547 (S. 97-108), Heft 589 (S. 599-610) fehlen in der Vorlage. Paginierfehler: Auf Seite 444 folgt Seite 443
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

THE PHOTOGRAPHIC NEWS. [January 1, 1869. I shall not attempt to deal with the vcxata questio as to the various chemical changes that the impressionable paper has to undergo in the various stages of salting, sensitizing, toning, and fixing, or to tell what must be the effect of acids or alkalis at the different stages. -These are in course of investigation by abler chemists, and the best of them, as far as I can see, are only groping their way. But I will come at present to what has been considered one grand cause of early deterioration, viz., the difficulty of removing the hypo sulphite of soda from the paper. To effect this important desideratum of expunging from the paper all traces of the fixing agent, every sort of washing machine has been tried that ingenuity can devise. The papers have been swirled for hours in water hot and cold ; pressed and swirled again, till one might suppose that their very substance was crushed out of them; counteractive chemicals have been used to convert or pervert the hypo sulphite into another material altogether. And yet we have not heard, on reliable authority, that security has been attained. By all means let such experiments be tried, and let the experimental prints be dated and kept for the guid ance of posterity, if they will go down so far. But are we at present, for general work, to adopt any of these new plans on the mere probability or possibility of success, and wait another twenty years for the result ? Better, surely, to adopt some modification of known processes that will insure a good measure of success at present, although this may, perhaps, be attended with a little extra trouble. The plan that I would recommend, as it seems so difficult to get the hypo out of the paper, is, not to put it into it. Take the picture upon glass, and afterwards transfer it; or, if paper is used at all in the first instance, let it be as thin as possible. It is the thick body and spongy nature of the paper used that create the difficulty : the thicker the paper, the more the difficulty is increased- 1 never got finer silver prints in my life than some which I once tried on very thin tracing-paper; and these, I believe,would be more thoroughly washed by pinning them on a board, and pouring a few panfuls of water on them (it could be done through the rose of a watering-pan), first on one side and then on the other, than thick paper would be by sweltering a whole day in a washing-machine; for it must be remembered that the currents do not reach the heart of the paper ; amid external agitation all is quietness at the core. Inevertriedmanyof theabovekind of prints,partly because it involved the trouble of albuminizing my own paper, there being none of that kind sold, and partly because I got upon another hobby, and lost sight of that method altogether. But the hint may be found of some use to those who wish to persevere with printing on albuminized paper, viz., to use the thinnest fine paper they can get in the market. The albumen gives very thin paper considerable strength to bear handling. Following out the above idea a little further, I have said that the best plan is not to put the hypo, or fixing material, whatever it be, into the paper at all. It has often been re marked that collodion positives on glass have been found very lasting. I have them more than fifteen years of age, unvarnished, and showing no symptoms of decay.* This may partly arise from the composition of the image being different from that of a common print; but not entirely from that cause, as it is well known that ill-washed negatives and collodion positives do very quickly fade. The permanence of these greatly depends on their proper washing ; but one tenth of the washing suffices that is needed for a silver print upon paper. Can we not, then, take a hint from this ‘I Why not print our positives on glass—by preference opal escent glass—wash them thoroughly, and then transfer them to paper ? The film being very thin, and supported behind by the hard glass, a stream of water poured from a jug or tap for a short time drives the fixing material out of them ; * We have one in our possession taken by Dr. Diamond, in 1850, some months before the collodion process was published to the world. It shows no change whatever.—Ed. Photo. News. and even though a faint trace should be left, it does not afterwards exhaust its whole power upon the print, but will become absorbed and weakened by the dispersion within the clean paper to which the picture is transferred, or on which it is mounted. In an ordinary paper print the injurious chemical comes out from the heart of the paper, where it is lurking in greatest quantity, and attacks the print; but in a transferred picture such as I have mentioned, any injurious chemical left in the thin film must be very small indeed, and, by spreading partly within the paper, must become so weakened as almost to be harmless. The plan recommended is nonovelty, so far as the mere pro duction of pictures is concerned; but I have not noticed that its adoption has been urged upon the grounds which I have now mentioned. Having got a couple of beautiful collodio- chloride prints on paper sent me by Mr. G. Wharton Simpson, who mentioned at the same time that they would not keep, as he had not taken time to wash more than the first excess of hypo out of them, I gave them a further soaking and washing myself; but it occurred to me at the time how much easier it would have been to insure the expulsion of the hypo had they been on glass. I therefore throw out the above suggestion as deserving consideration upon the grounds stated. If a sheet of opal glass is slightly waxed, then well rubbed up, and coated with the prepared collodion or with salted albumen above ordinary plain collodion, it can be sensitized and as easily printed on as on paper ; and it is not difficult to lift it from the glass to clean paper by one or other of the methods that have long been known. Such a print will be found to possess the fine polish, though, perhaps, not the ivory-tone, of Mr. Burgess's Eburneum specimens, one ot which, recently sent me, I must characterize as a morsel of great beauty, and beside which any ordinary print looks coarse. While I think, however, that this method might be adopted with several advantages for small pictures, still, for those of a larger size and greater value, I am disposed to recommend the carbon. DRY BLATE WASHING BOX. BY A. SEELEY. As I have had a good deal of experience with tannin plates, and as that process is generally charged with a great tendency to pinholes, I venture to trouble you with one or two suggestions. At one time I never went out with a batch of plates with out feeling certain of having to spend much time on my return in touching up spots, or stoppingout skies; now the case is quite the other way. 1 tried all kinds of washing, distilled water being as bad as any. One day the thought struck me that if 1 put the plate into an upright dipping-bath, and caused a constant stream of water to pass over it, any formation of iodides or chlorides, &c., would be carried away. This led to the idea of a compound bath such as I have sketched below. B 5== OVERFLOW c M 144411// A is the inlet for water constantly flowing in a small stream. B a pipe from which is always dropping a dilute solution of common salt, with a small quantity of acetic acid. C, a half-inch pipe, to act as an overflow or waste. D a quarter inch pipe, to take off the heavy chloride of silver, and anything that goes to the bottom. Spaces 1 to 8,