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Substitute fob Glass Negatives.—Ever since the introduc tion of the collodion process, experimenters have busied them selves in seeking for a more portable and less fragile support, for the sensitive film, than glass. Ordinary gelatine bromide paper, even when waxed, shows the grain of the paper, and is thus hardly suitable for negatives of small dimensions. The readers are aware, no doubt, that excessive pressure will produce a similar result, this being exemplified in Woodbury’s photo- filigrane process. The Photographische Notizen refers to a new paper recently introduced by a Japanese, which is said to be very strong and so transparent, that it can be employed for glazing windows instead of glass panes. The paper is prepared from the fibre of a Japanese water plant. MARKING the Right Side of Lantern Slides.—At a recent meeting of the Photographic Club, the question of marking lantern slides, so as to ensure their always being shown in the lantern the right way was considered, and it was agreed that the Club marking should be as follows :—" That each slide shall bear on its face either two white patches, one on each upper corner, or a distinct white line on the face, along the upper edge.” By the face of the slide is meant that side which, when held next the eye, shows the picture, or any reading, the right way. The World’s Platinum.—The platinum diggings of Russia are near Bogoslowsk, Miask, Newjansk, Nischnei Tagilsk, in the Ural Mountains. They were discovered in 1824; and at six places—in 1868, 1869, and 1870—from 494,000, 367,000, and 263,000 tons of sand, 6,675, 7,770, and 6,455 pounds of raw platinum were obtained respectively. The metal contains always some other substances; thus Le Play found, in a sample from Nischnei Tagilsk, 75'1 platinum, 1'1 palladium, 3'5 rhodium, 2'6 iridium, 6 osmiridium, 2'3 osmium, 4 gold, 1 copper, and 8'1 iron. The raw metal is almost entirely sold to England and Paris, at a price of about £14 per pound of pure metal. It is there refined before it can be worked up into manufactured articles.—The American Druggist. Humours of Photographic Sitters.— " Fancy pictures ! Lord help us, they are all 4 fancy.’ It’s a nuisance, that’s what it is,” said a young operator, “ having to get some new gimcrack for sitters without brains, and I’m dead tired of it! Take babies with one shoe in their mouth, for instance, all bundled up in clothes, so that they are nothing but dry goods, or no clothes at all. There’s the wash basin style—baby supposed to be in its bath, or it must have one bare foot. Anything to make trouble, I say.” “ But older people do not act in that way, do they ?” “Don’t they? Just look at the old negatives we have. One fellow standing on the shoulders of another. We took six brothers here in town that way once—all middle-aged men, or nearly so. Then some fellow comes in who wants to show a silk-facing to his coat—overcoat at that. And badges ! Lord! we have them from the size of a five-cent, piece up to a dinner plate. And uniforms! Well I when you see the picture of a soldier with three rows of brass buttons on his waist, a sword dangling at his side, and a fur helmet on as big as a bushel basket, you can just be sure he never smelt powder or marched anywhere except on a pavement. Girls, too, that want to look like actresses, and roll their eyesup and clasped their hands. We have one lady-customer who has been photographed in twenty-five different styles—they j ust wear me Out with their nonsense.”—Detroit Free Press. Photographic Club.—The subject for discussion at the next meeting, on Wednesday, will be “ On the New Rapid Papers for Development. Uo Uorrespondents. *,* We cannot undertake to return rejected communications. E. H. M.—The difficulty only occurs with a few samples of asphalt, and one remedy is to smear the film over with a trace of thin lithographic varnish before developing with benzole, and time should be allowed for the varnish to slightly act on the film. Re transfer ink is not very suitable for inking in, and you will find that an ordinary printing ink (either lithographic or typographic) will adhere better. J, W.—If you read the present number of the News attentively, you will arrive at a solution of what is now so incomprehensible to you. G. John Sutton.—1. Equal parts of carbonate of potash and water. 2. One part of sodium sulphite and four parts of water. 3. One part of carbonate of soda with one and three-quarter parts of water. Jas. GOULBORN.—It will not altogether prevent decomposition, but will certainly do very much to retard it. Other reactions besides mere oxidation take place. Dover.—The cost of provisionally protecting for six months is £1 for stamp, and a few shillings for incidental expenses. Any stationer will obtain you a set of forms, or you can write to Evison and Bridge, Law Stationers, Chancery, Lane London, for them, and the stamp can be obtained to order at any post office. Tulloch Ard.—The slides you mention are, we believe, wet collodion positives ; and, judging from the appearance, we are in clined to think that the transparencies are made very thin in the first instance, and are then intensified by Eder’s method with lead. After thorough washing, immerse the transparency in— Distilled water ... ... ... ... 100 parts Red prussiate of potash (ferricyanide) ... 6 ,, Nitrate of lead 4 „ When it has become yellowish-white all over, wash well and, place in a mixture of liquid sulphide of ammonium 1 part, and water 4 parts. Wash. F. S. B.—You gave permission for its use in the News, only on condition that it was inserted before Christmas ; but it was im practicable to insert it so soon. Th os. Coan.—We have no recollection of the matter. C. H. Evans.—The address of Mr. Woodbury has been forwarded to you by post, and he will doubtless give you all information. H. VERMEESCH Adel.—1. Your experience is quite new to us, and as the solutions remain clear on mixing, we should conclude that but little chloride is present. Neither in tbe case of gelatine nor collodion do we know of any likely means of preventing pre cipitation, excepting by the use of a large excess of ammonia ; and if this were present you would at once recognize tbo fact by the smell. 2. We think not, but have never made special experiments in the direction indicated. 3.—Sulphuric acid 6 fluid ounce Dried nitre 3J ounces Water 1 "fluid ounce Dry cotton wool 60 grains Mix the acid and water cautiously, and stir in the nitro with a glass rod. When the temperature of the mixture has fallen to 150° F. add the cotton-wool, previously pulled out in small tufts and allow it to remain in the mixture for ten minutes. Thoroughly wash in the ordinary way. Quandary.—1. To test for hyposulphite, soak some cuttings of the mount in just enough water to cover them, and after filtering the liquid, add it to a solution of iodide of starch, made so dilute as to only have the faintest tinge of blue. A discharge of the colour indicates hyposulphite. To make the iodide of starch solution, boil a dozen grains of starch in an ounce of water, and when cold, add sufficient of a solution of iodine in water to strike a bright blue colour. Dilute this considerably before using it as a test. 2. One of the purest forms of starch obtainabl, is the best quality of arrowroot. F. W. W. B.—1. If the article was labelled correctly, it is chlo ride of calcium, and not the preparation known as chloride of lime. It is best to order “bleaching powder” when this latter is required. 2. You can obtain it from the Autotype Company. 3. The quality known as Nelson’s opaque will answer very well. Amateur.—1. In such a case you cannot do better than use a simple syphon-trough, such as is represented on page 551 of our last volume. 2. Let it remain in action about twelve hours. 3. None whatever, but it is as well to varnish the zinc with Bruns wick black, or some other similar varnish. II. W. B.—There is probably hyposulphite in the cardboard ; see answer to “ Quandary.” Rustic.—1. The name is unknown as that of a maker, and gives no indication whatever of the quality of the lens. 2. If ic is an ordinary portrait lens, you certainly cannot include a wide angle with it; but why not fix it on the camera, and let the result answer for itself. 3. How do you suppose that we can tell with out seeing the instruments; but in this case also a simple trial will give you the information you want. 4. There is no low- priced lens which will do what you require. John Baird.—You misunderstand, as thorough fixing and wash ing before intensification is of especial importance. The presence of a trace of hyposulphite is fatal. Ghe Photographie Nletus. SUBSCRIPTIONS. Including Postage to any part of the United Kingdom:— Yearly ... 15s. Od | Half-Yearly ... 7s. 8d. I Quarterly ... 3s. lOd. To the United States, the Continent, ana the Colonies :— Yearly ... 17s. 4d. I Half-Yearly ... 8s. 8d. | Quarterly ... 4s. 4d. To India (Yearly) 19s. 6d. ADVERTISEMENTS IN COLUMN. Not exceeding Five Lines (36 words)... 3s. Od. Each Additional Line 0s. 4d. Repeated insertions, and special positions or style, by centract.