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5 84 THE PHOTOGRAPHIC NEWS. | DECEMIBER 3, 1880. When are we to have a national Photographic Portrait Gallery ? The subject has several times been mooted, but, strange to say, never secured the faintest breath of encourage ment. At first, we were told, it was necessary to get photo graphs that would not fade; and now these are to be had, a cry is raised against the unsatisfactory nature of the presen day photographs. In the meantime valuable negatives of bygone celebrities, which are in existence, are likely to get lost, or broken, or scattered through the breadth of the land. Many of the great men who lived between 1840 and 1850 were depicted by the Daguerreotype process ; but it would be hard work, indeed, to hunt up their pictures now. In some cases, the little plates, all stained and discoloured, have been cast on one side aud forgotten, while coarse wood-cuts and engravings are treasured with care. But who would care to look at a big, black print of the late Sir Robert Peel, if he could see the statesman’s living reflection clearly limned upon metal or paper, his bold features the same as when he lived, and moved, and had his being ? The Iron Duke is very well in bronze and marble, but our children hereafter will be clamouring to see the hero of the Peninsula and Waterloo as he lived among men ; not as a cold glazed statue, but with life and breath within him, with animated face and piercing eye, as the Daguerreotype or photograph alone can show him. Every year that passes will make the collection of early Daguerreotypes more and more difficult, and it will be sad to reflect, when, one day, our tardy authorities take the matter in hand, that many of these living portraits have been lost to the nation forever. Daguerreotypes, by the way, as many of our readers know, copy easily and successfully, producing far better results than are to be secured from silver impressions. “ A modern major-general,” according toMessrs. Sullivan and Gilbert in the Pirates of Penzance, is a scientist con versant with all the isms, asms, and ologies under the sun. The late Duke of Wellington, however, did not consider it so all-important to be up in the very latest features of science, for there is a story extant of the simple old soldier paying a visit to Carpenter and Wesley’s, in Waterloo Place, to see the solar microscope in the early days of that wonderful instrument. The Duke had re peatedly heard of the invention, but he could never per suade himself to forego his matutinal ride in the park to see it. One morning, however, it came on so foggy that a ride was well nigh impossible, so he turned up Waterloo Place, and directed the groom to hold his horse while he dis mounted. “ We can’t show the microscope to anyone this morning, sir,” said the assistant. The Duke was not used to be thwarted. “ What do you mean, sir ? I am the Duke of Wellington I Pray, let me see it at once.” And then the hero of Waterloo had to be informed by the grinning shop man that you can’t look at the solar microscope unless the sun shines. FRENCH CORRESPONDENCE. Magic Photography—ELEOTRo-METALLIC Photometers— Emulsion of Gelatine and Pyroxylin—Printing by Ferrous Oxalate—Tribute of RE'PECT to M. PorEVIN, Photographij by Magic.—A phosphorescent substance placed iu a vacuum and submitted to the action of an elec tric current will emit a strong light. Why should the light thus produced not bo used for taking photographic prints by the aid of some very sensitive medium, such as gelatino-bromide? A highly-amusing experiment might be made in this way, and one not less surprising to the audience, if they were told beforehand that no kind of light, either solar or artificial, was employed. What would be required would be some kind of flat receptacle from which the air could be exhausted ; it must have a glass front behind which would be placed the phosphorescent surface, and be capable of being inserted in an electric circuit. The electric wires and battery could be concealed beneath the lecture table. The room having been sufliciently darkened to allow of the sensitive films used being mani pulated without injury, the negative plate, and the sensi tive surface on which the impression is to be taken, could then be applied to the glass face of the receptacle contain ing the phosphorescent substance ; the whole is covered with a black cloth, and the current is turned on. In about five seconds an impression of the image would be taken, and the development, which would require a few minutes more, could then be proceeded with. This latter process might be effected in the same mysterious way. The printed paper is dipped into a covered basin, and the light is turned up again. In about two minutes, if not less, the paper might then be rapidly passed into the hyposulphite bath, and afterwards into water, and quickly dried on blotting-paper. By this arrangement a number of prints could be taken in a quarter of an hour, and could be handed round to the amazed spectators. The whole trick reminds one a little of the mysterious cabinet of the brothers Davenport, only there is no cabinet, and the spirits are not summoned ; indeed, the effect might be heightened by declaring that the whole was managed by legitimate scientific means. The general idea is suggested to me by the circular of M Christian, who, it appears, actually does shut himself up in a cabinet, although, as I have shown, this piece of furniture is quite superfluous. An improvement might be effected by devising a sensitive paper possessing its own developer, so that it would be necessary, after exposing it, to plunge it into water. While on this subject, I may mention that I am at present en gaged in experiments for taking positive impressions by development, and that I hope by this means to arrive at a rapidity of execution and a permanence which can be ob tained in no other way. I reserve a detailed account of these experiments for the Year-Book. Suggestion for a New Photometer.—Mr. Bell’s experiments with his photophone have suggested to me an idea for an electric photometer. In Mr. Bell’s instrument is utilised the property of selenium, when part of an electric circuit, to affect the resistance to the current according as this substance is acted on by light. Now, it seems to me that this property could be taken advantage of for a photometer. The appa ratus would consist of a condensing lens, and a number of stops of different apertures, of a plate of selenium, or some other form of that metal, which would allow of the surface to be exposed being increased as far as possible. Further, if a dry electric pile and insulated wires be attached to the selenium, and, lastly, of a galvanometer, the light being now thrown on the selenium through the different stops suc cessively, the indications given by the galvanometer corres ponding to the diameter of the aperturo of each stop woull be first observed. Afterwards, using the same stop, the various indications of the galvanoinetei could be read off, corresponding to the different degrees of luminous intensity at noon, in full sunlight, in cloudy weather, with a declining