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January 16, 1863.] THE PHOTOGRAPHIC NEWS. 33 mission, so that a wet plate was ready at any moment the artist might require it. Mr. WALL thought that the commercial interests of photo graphy should be subservient to its art progress. Some conversation followed, in which the Chairman, Mr. Fry, Mr. Leake, and others, thought that no advantage would be gained by the use of dry plates in the studio, and that portrait ists would never abandon the wet process. A desultory con versation on the possibility of keeping wet plates for twenty minutes or half an hour in the dark slide, during the arrange ments of portraiture, followed, many precedents being quoted in support of the practice. The Bov. F. F. Statham made some interesting remarks on the phases of photography, illustrated at the International Exhibition. He referred to the variety of style which might be introduced into portraiture—referred, for example, to the pro ductions of the Dutch painters, in which portraits were produced as character pictures, so that they were interesting and valuable as works of art long after the individuals portrayed were for gotten. Mr. Simpson had been reminded, by some remarks of Mr. Statham, in reference to card pictures of landscapes, of one he had just received from an anonymous correspondent, which he wished members to examine as one of the most perfect small pictures ho had ever seen. It was a view of Edinburgh, from Calton Hill, in which every part of the foreground was most per fectly and brilliantly defined, and yet fine natural clouds were secured in the sky. He had no information as to how it was produced, except that it was on a Fothergill plate. He did not know by whom it was produced; but, from collateral evidence, he was disposed to attribute it to Mr. Archibald Burns, of Edin burgh, a well-known skilful Fothergill manipulator. After some further conversation, Mr. Fry, at the call of the Chairman, said, that the able remarks of Mr. Statham had quite cut the ground from under him for further comment. There was first one subject to which he would refer. It Would be within the recollection of members that, two years ago, ho read a paper before this society, on printing in skies, and other forms of double printing, with a view to artistic effect. It met with some opposition, and was, in fact, mani festly a premature paper—one which photographers were not then ready for. He was very happy in being able to call attention to many prints in the Photographic Exhibition (which would open in a few days), in which photographers, of un doubted skill and reputation, had adopted the system referred to, and with manifest advantage to their pictures. The Chairman proposed that Mr. Simpson bo requested to ascertain the artist who had produced the charming little card landscape they had been examining, and the terms at which a sufficient number could be procured, in order that each member of the society might have in his possession a picture which might serve as a standard for imitation. This was carried by acclamation. Mr. Leake called attention to two pieces of lead pipe, quite eaten through by the vapours of acetic acid. Mr. Statham suggested that the society should keep a Desideratum Paper, on which should be entered, from time to time, a note of all the especial wants which occurred in the art. Such a memorandum would preserve a record before the eye, of things which would often otherwise be forgotten. It was announced that, at the next meeting, Mr. George Price would read a paper on the Theoretical Principles of Positive Printing. The proceedings then terminated. • Uhe Unternational Gxhibition. REPORT of the jury on photography and PHOTOGRAPHIC APPARATUS* THE PRINTING COMMITTEE. Circular letters were addressed by the committee to photographers of expe rience and reputation, asking them to assist in the purposes of the inquiry by information and suggestions, and also by contributions of prints, with particulars of the method of producing them, in order that the fullest experi ment and examination might be made. The results of this inquiry were furnished in the following Report " Evidence of Permanence. " The Committee have unquestionable evidence of the existence of Photo * Continued from p. 21. graphs which have remained unaltered for more than ten years, prepared by salting plain paper with a chloride, afterwards making it sensitive with either nitrate of ammonio-nitrate of silver, fixing with a freshly-made solution of hyposulphite of soda and washing in water; also of positives produced by Mr. Talbot’s negative process. " They have not been able to obtain evidence of photographshaving been prepared at all upon albumenized paper, or coloured with a salt of gold or fixed with “ old hypo ” so long ago as ten years. “They have, however,ample evidence of the existence of unaltered photo graphs so prepared, five, six, and seven years ago. " They have not found that any method of printing which has been commonly followed, will necessarily produce fading pictures, if certain pre cautions be adopted, nor have they evidence that any method which has been adopted, will not produce fading pictures unless such precautions are taken. “ Causes of Fading. « The most common cause of fading has been the presence of hyposul phite of soda, left in the paper from imperfect washing after fixing. “ The Committee think it right to state, that they have been unable to find any test to be relied upon, which can be used to detect a minute portion of hyposulphite of soda, in the presence of the other substances which are obtained by boiling photographs in distilled water, and evaporating to dry ness ; yet they have no doubt of the truth of the above statement, from the history given of the mode of washing adopted. “ The continued action of sulphuretted hydrogen and water will rapidly destroy every kind of photograph ; and as there are traces of this gas at all times present in the atmosphere, and occasionally, in a London atmosphere, very evident traces, it appears reasonable to suppose that what is effected rapidly in the laboratory, with a strong solution of the gas, will take place also slowly, but surely, in the presence of moisture, by the action of the very minute portion, in the atmosphere. “ The Committee find that there is no known method of producing pic tures which will remain unaltered under the continued action of moisture and the atmosphere in London. « They find that pictures may be exposed to dry sulphuretted hydrogen gas for some time with comparatively little alteration, and that pictures in the colouration of which gold has been used, are acted upon by the gas, whether dry or in solution, less rapidly than any others. “ They also find that some pictures which have remained unaltered for years, kept in dry places, have rapidly faded when exposed to a moist atmosphere. “ Hence it appears that the .most ordinary cause of fading may be traced to the presence of sulphur, the source of which may be intrinsic from hypo sulphite left in the print, or extrinsic from the atmosphere, and, in either case, the action is much more rapid in the presence of moisture. « Mode of Mounting Photographs. The Committee find that, taking equal weights, dried at a temperature of 212°, of the three substances most frequently used, viz.: gelatine, gum, and paste, the latter attracts nearly twice as much moisture as either of the former; and, as in practice, a much smaller weight of gelatine is used than ot gum, gelatine appears to be the best medium of these three ; and the Committee have evidence of fading having, in some cases, been produced bv the use of paste. J " In illustration of some of the circumstances alluded to above, the Com mittee think it well to mention some instances of prints at present in their possession. “ Out of several prepared together in 1844, three only are unaltered, and these were varnished soon after their preparation with copal varnish. “ Half of another print of the same date was varnished, and the other half left; the unvarnished half has faded, the varnished remains unaltered. Three pictures were prepared in 1846, all at the same time, with the same treatment: when finished, one was kept unmounted ; the other two were mounted with flour-paste at the same time, one of these latter having been first coated with Canada balsam ; at present, the unmounted one and the one protected with the balsam are unchanged, whereas the other has faded. “A picture prepared in 1846 was so exposed that the lower part of it became wetted with rain ; at present the part so wetted has faded, while the rest of it remains unaltered. Several pictures were prepared and mounted about ten years ago, and kept in a dry room for about three years without any change, after which they were placed in a very damp situation, and then faded decidedly in a few months. “ The Committee propose very shortly to actually test the durability of the various modes of printing, by exposing pictures to different treatment, and they have been fortunate enough to obtain a grant of space for this purpose from the Crystal Palace Company. “ The Committee make the following suggestions, arising out of the above Report:— “ 1. That the greatest care should be bestowed upon the washing of the prints after the use of hyposulphite of soda, and for this purpose hot water is very much better than cold. “ 2. The majority of the Committee think that gold, in some form, should be used in the preparation of pictures, although every variety of tint may be obtained without it. “ 3. That photographs be kept dry. “ 4. That trials be made of substances likely to protect the prints from ai and moisture, such as caoutchouc, gutta-percha, wax, and the different varnishes.” CARBON PRINTING—THE DUC DE LUYNES’ PRIZE. The methods of printing, toning, and fixing photographic pictures had up to this period not undergone much modification since their original dis covery. An image formed by the action of light upon paper prepared with the chloride of silver and fixed by means of a solution of hyposulphite of soda was found to be tolerably permanent, but its colour, a reddish brown, was unsuited to the purposes of pictorial effect. The addition of chloride of gold to the fix ing solution aided in producing a variety of purple black ami neutral tints, which were much more agreeable and satisfactory. This addition, however, introducing an element of decomposition in the fixing solution, was thought by many to increase the chances of fading. To avoid this difficulty a new method has been proposed, in which the toning of the print by means of a solution of gold is conducted prior to the process of fixing by means of hypo-