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670 THE PHOTOGRAPHIC NEWS. [October 16, 1885. AProceedings of Sorieties. London and Provincial Photographic Association. A meeting of this Society was held on Thursday, the 8th inst., W. E. Debenham in the chair. The employment of tin foil separating clips for packing gela tine dry plates was again discussed, and opinions favourable thereto expressed; but A. Haddon thought that strips of para ffine paper of similar thickness would answer as well. This was not the experience of A. L. Henderson, whose plates packed in that manner showed marks either from pressure or chemical action. J. Barker then showed some negatives exhibiting green fog round the margins only. The plates, which belonged to a friend, had been packed for two years with tissue paper between them, and he supposed that a damp atmosphere had decomposed the unprotected gelatine. The covered portions yielded perfect negatives. The Chairman pointed out the distinction between ordinary green fog and the iridescent kind resulting from an impure atmosphere. A very small quantity of sulphur would, he said, in two years produce a similar result. A. Mackie spoke of the deleterious effect of house gas upon plates even when kept in a moderately dry room, and he noticed they became less sensitive. A. L. Henderson remarked that negatives which appeared in development to have cleat shadows, often turned out to be bad cases of green fog. Some gelatines were liable to decompose, but speed and quality could be got with them, which was not attainable by other means. The Chairman had attained the highest speed with hard gela tine, and he did not find that hardening with chrome alum altered the result. This led to a short discussion on frilling, in which Messrs. Cowan, Henderson, and the Chairman took part. W. H. Hislop showed a negative of the S. S. liepublic, steam ing out of New York Harbour. It was an Eastman film, taken from the deck of the Urania, about three minutes previous to the recent collision. The following question was then read: —“ Can anyone explain why salicylic acid, when mixed with water and methylated alcohol, discolours when exposed to light ? ” A. Cowan had long noticed this, and attributed it to the methyl. Some samples of spirit had turned it deep red without exposure to strong light. The subject was further discussed, but nothing new elicited. Another question :—“ Shall this Association henceforth call the usual fixing salt by its proper name, and adopt the decimal system of weights and measures ? ” was then dealt with. A. Cowan saw no reason for changing familiar words like “ hypo ” and “ pyro,” but advocated giving formulae in parts as being easier than the metric system. The Chairman considered a dual decimal system preferable to any. W. H. Harrison, A. Haddon, and others spoke in favour of the question, which was adopted, they said, by all scientific bodies, and was universally understood. W. K. Burton thought there was a good deal to be said in favour of the dual system ; and after some further discussion the matter dropped. “ What is the best strength of fixing solution for plates which have been more than ten minutes in developing or other solu tions immediately before ? ’’ was then discussed. W. K. Burton could not see that length of soaking would make much difference ; and A. L. Henderson pointed out that gelatine could not absorb more water than it originally contained at the time of coating. The Chairman said that one part of the fixing salt to four of water would be a useful strength, whether the plates had much or little soaking. C. H. Cooke had some plates which gave pinholes if soaked in water before development. W. K. Burton thought water would have no effect in producing pinholes unless some substance had been put into the emulsion which was soluble in water. Several members offered suggestions, but, as the mode of preparation was not given, it could not be settled. A. L. Henderson had suggested the possibility of an impure sample of alcohol causing the spots above alluded to, and he had, on a former occasion, added naphtha to a perfect emulsion, the effect of which was to cause spots like fine sand dusted over the plates. Methods of purifying alcohol then became the subject of discussion, the usual plan of shaking it up with quicklime meeting with general favour. The Chairman, having drawn attention to a statement made in one of the journals by a member, that silver citrate gave cold tones for printing out, he desired to say that, in his hands, it was quite the contrary ; he did not get either blue-black or blue tones, but warm colours, which was the characteristic of the citrates. North Staffordshire Amateur Photographic Association. The fortnightly meeting was held on Wednesday, October 7th, the President occupying the chair. It was decided that the proposed exhibition of the work of amateurs, to be held shortly, be confined solely to this Society, and that the co-operation of other societies be solicited another year. F. Leek showed some photographs taken by himself in Dove dale, &c. J. Burgess showed a negative taken on sensitive flexible tissue. After some discussion upon the respective merits of paper and glass as a support for the sensitive film, the opinion of the majority of the members was expressed, that until the former was shown to be practically better, or at least equal to the latter, then double-backs would not be laid aside. The Honorary Secretary having at the request of some members promised to give a demonstration of the carbon pro cess at the next meeting, the proceedings terminated. Derby PHOTOGRAPMIC Society. The monthly meeting of this Society was held on Wednesday, October 7th, in the Mechanics’ Institute, Richard Keene occu pying the chair. The proceedings began with a show of cameras. Among those exhibited were Scott’s, McKellen’s, and a new one just published by Marion and Co. (shown by Mr. Keene). H. Bolden also exhibited two cameras of curious construction. R. Keene then) gave a short address to beginners on “What to Photograph.” Among other things he remarked that those who lived in Derby had no need to wander far abroad to find suitable subjects. Within a radius of five miles there was an almost inexhaustible supply of charming views to be obtained, and of great variety. H. Bolden followed with advice on “ How to Take the View.” He recommended the use of good apparatus, and said the best size of camera for general use was the half-plate, 74 inches by 44 inches, or 7J inches by 5 inches. It was important that the camera should have a swing-back, and also side-swing. Illustrations of the benefit of these were given. He described and illustrated the use of various lenses, such as long dist ance, wide angle, Ross’s Symmetrical, and Dalmeyer's Rapid Rectilinear. He recommended a careful study of the ground with a view-meter before the fixing of the camera. A bright showery day was the best, and the best light was when an extremely thin cloud just veiled the sun. Much other practical advice was given. C. B. Keene then developed two plates which had been exposed by F. Cooper, and thus a most instructive evening was brought to a conclusion. At the next meeting of the Society (November 4th), a photo graph exchange will be held, and members are invited to bring specimens of their work. Edinburgh Photographic Society. The final meeting of the session was held in 5, St. Andrew Square, on Wednesday evening, 7th October, W. Forgan in the chair. The minutes of the last meeting having been approved, Arthur Edwards and Peter Kerr were admitted ordinary mem bers, and sixteen names nominated for election at next meeting. The Chairman then intimated that there had been sent in a large number of pictures for the competition for the presentation print, but he regretted that out of a membership of more than four hundred, only six had come forward as competitors. The Council had carefully examined the work sent in, and awarded