The photographic news

• Bandzählung: 24.1880
• Erscheinungsdatum: 1880
• 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
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• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Bemerkung: Exemplar unvollständig: Seite 1-82 in der Vorlage nicht vorhanden
• Strukturtyp: Band

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• Strukturtyp: Ausgabe

150 THE PHOTOGRAPHIC NEWS [March 25, 1880. Uge 2gotograpkir 8ebs. Vol. XXIV.N0.1125-MARCH 25, 1880. CONTENTS. page Photography In and Out of the Studio 145 On the Reduction of Collodion and Gelatine Emulsion Residues. By Captain W. do W. Abney, R.E., F.R.S 14G At Home.— The Woodbury Permanent Printing Company at Kent Gardens, Ealing 146 Art and Nature as Represented by the Camera and the Brush. By W. H. Davies 148 Are Gelatine Plates Suited for Landscape Work ? By II. Man field 149 Fixing and Washing Silver Prints 150 Notes 151 Topics of the Dav.—Unhealthy Dark Rooms. By G. Bradforde 152 On Converting Old Negative Bath in Printing Bath. By G. 153 Rapid Dry Plates. By H. W. Bevan 154 Lateral Spread of the Image During Alkaline Development. By Captain Abney, R.E., F.R.S 155 Correspondence 155 Proceedings of Societies 155 Talk in the Studio 156 To Correspondents 156 Patents. Compiled by Mr. Des Vux 156 FIXING AND WASHING SILVER PRINTS. Mr. Marshall Wane’s able paper on the subject of wash ing prints, which was read at a recent meeting of the Edinburgh Photographic Society, is likely to call attention once more to a very important matter. There are many who profess a firm belief in the stability of silver prints, if only properly washed, but none, unfortunately, can say how perfection in this respect is to be secured. Mr. Mar shall Wane, like Mr. England, and several others who have recently favoured us with a description of their method of washing, is an agitator ; he believes in prints being kept in constant motion during washing, and not simply sub jected to a quiet stream of running water. Mere sodden- ing for hours together does not meet his views, and we may take it that the majority of photographers are in accord with him. At the same time we must not forget that sometimes all the washing in the world will not prevent pictures from going yellow. Mr. Wane spoke, and with good cause, against the yellow and buff cards that are so much in vogue just now, and which, there is every reason to believe, have a good deal to do with the fading of photo graphs ; but we do not think he made good his complaint against evil-smelling albumenized paper. Material of this kind may be suspicious, objectionable, and altogether un trustworthy, but we do not think chemists would pro nounce bad odour to be evidence of its likelihood to yield unstable prints. But, unfortunately, a thorough washing will not always give stable prints; as photographers know very well, albu menized prints fade every day upon which the greatest pains have been taken in the washing trough, while others that are known to have been scamped, or but hastily rinsed, retain their freshness and vigour for years. There is, in a word, something even more important than wash ing to be considered by photographers, if they hope to secure permanent silver prints. The fixing in many estab lishments is done without due care ; it is relegated to a boy who has not been on the premises three months, or to a careless girl who objects to the dipping of her fingers continually in the soda solution. The hyposulphite gets exhausted, or the prints are not sufficiently separated in the fixing operation, and the consequence is, that the in genuity and trustworthiness of the washing apparatus are all in vain. Many photographers have an idea that photo graphs printed in the winter are more permanent than those produced in summer, for the reason that the fixing is usually done by candlelight, and this brings to our mind a communication which was made to the Photo graphic Society, six or seven years ago, by Dr. E. J. Gayer, of the Indian army, and which has never had the attention it deserved. Dr. Gayer not only recommended the fixing of prints by candle-light, or in the dark, but further insisted on the employment of a very strong solu- ' tion of hyposulphite. To his mind, as much as six ounces of hyposulphite of soda should be used in fixing a single sheet of albumenized paper. A print, say eight inches square, required for its perfect fixation one ounce of hypo sulphite of soda dissolved in eight ounces of water. Dr. Gayer took his print into the dark room, immersed it in the fixing solution for ten minutes, and not until after it was rinsed in water did he bring it back into the light, to go through the usual operation of washing. He threw away the fixing solution after it had been used once, and fixed the next print in a fresh supply. Unless the process of fixation was carried out in this way, Dr. Gayer averred that an insoluble silver salt remained in the whites, which sooner or later must be acted upon by light, while prints treated in the manner he described were proof against an Indian sun for ten years at least, as he vouched by his own experience. Although we can hardly expect photographers to follow Dr. Gayer’s example in its entirety—the amount of hypo sulphite prescribed is extraordinarily high—it is still be yond a doubt that many photographic chemists believe in the plan of fixing in the dark and employing strong hypo sulphite solution. Mr. Spiller, who has given the subject of faded silver prints considerable attention, attributes the circumstance in a great measure to the formation of an insoluble compound in the whites of the picture, which may be termed an albuminate of silver. This compound once formed is not to be removed by any amount of wash ing, and it changes colour on being continually exposed to the action of light. We do not know if Mr. Spiller has found out whether albuminate of silver is formed when the fixing of the prints is conducted in the dark, but few photographers will deny that the employment of a very strong solution of hyposulphite is a measure to be recom mended. Indeed, we may safely go further, and say that a good deal of fading is brought about by the carelessness of photographers in employing spent solutions, which but imperfectly dissolve out the chloride from their prints. One other cause of fading, beyond that of the mounts, must be borne in mind, however, in discussing the stability of silver prints, and this cause is independent of the ope rations of fixing, washing, and mounting: we mean a vitiated atmosphere. In a coal and gas consuming country like this, the air of our towns and cities must always be more or less contaminated with sulphur. An ordinary sample of coal contains about one per cent, of sulphur, and coke, unless it is very good, contains the same. Therefore, for every hundred tons of coal or coke consumed in our cities, one ton of sulphur is given off into the air in the form of sulphurous acid, from whose attack few objects are safe. In our apartments, again, the gas burning in dining-room or library contains plenty of the destroying sulphur, and when we remember that the photograph is, after all, but a thin film of metallic silver, and silver is of all metals one of those most prone to suffer from the action of sulphurous acid, the picture must indeed be well protected if it is not to sustain injury. Th us, to render the silver print permanent we have not only to eliminate all the hyposulphite by washing, and prevent the formation on the film of an insoluble com pound sensitive to light, but we must also take care, when we have secured this end, to mask the image in such a way that fumes and vapours are without effect upon its surface. The mounting of photographs against glass is, perhaps, the most efficient protection, but varnish, collo dion, and even a polish of wax, are valiant defenders of the silver photograph. Many, in framing photographs, place a card mount between print and glass, thus leaving a space into which vitiated air is not long in penetrating. Such a frame is no protection whatever. But defend silver prints as you may, it is the operations of fixing and washing upon which their permanence mostly depends ; these should at least get as much atten tion from the photographer as he gives to the perfection of his negatives.