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192 THE PHOTOGRAPHIC NEWS. Air-tight Packages.—According to the American Drug gist, a German firm supplies chloride of lime packed in the following manner :—Quantities of quarter, half, and one kilo, are wrapped first in strong paper and sealed. The packet is then dipped for a moment in melted resin, which is as nearly cool as it can be to be fluid. This forms a perfectly air-tight varnish, and the parcel is lastly wrapped in a good paper and labelled. The idea is a good one, and may be adopted with advantage in packing photographic chemicals. Decomposition of Organic Acids BY Sunlight.—According to H. de Vries, solutions of oxalic, citric, tartaric, and malic acids are all decomposed by light in the presence of oxygen. The three last-named are first converted into oxalic acid, and finally the latter is oxidized to carbonic anhydride and water. The blue rays cause this oxidation, and the process goes on most rapidly in thin layers of dilute solutions, through which a stream of air is passed. Ferric salts in the acid solution act in the same way as oxygen, and thus the author suggests that this property of iron, of oxidizing organic compounds in the presence of light, may perhaps play an important part in the organisms of animals and plants.—Journal of the Berlin Chemical Society. Photographers “Playing Low” in Derby.—“The latest improvement in photography. By this new and beautiful process, portraits can be taken at your own homes in a style which was not possible before, at prices which place them within the reach of all. You can have a group comprising all the members of your family for one shilling. These portraits, being taken in the open air, are taken with a rapidity that is truly astonishing, and being taken on the new American medium, can be finished and delivered in a few minutes. Gentlemen’s houses, dogs, horses, &3., photo graphed on the shortest notice. As our stay is limited, you are requested to give your order at once. Please do not destroy this circular, as it will be called for.” The above is the reprint of a bill which has been circulated in Derby by a troop of travelling photographers. It will be noticed that the bill is without a name, neither is there any address. Pushing Business.— Not a bad story this. A Birmingham solicitor, whose father is far advanced in the sere and yellow leaf, persuade 1 the old gentleman to accompany him one day this week to a photographic establishment and hi ve his portrait taken. Tae venerable parent consented, and was forthwith photographed. Judge of the dutiful son’s feelings when on the following day, a canvasset from the photographer’s cilled upon him with a suggestion that he should have an “enlarged copy of the old gentleman taken in water-colours before anything happened to him." This is one way of pushing a trade, and no mistake.—Birmingham Daily Mail. Photographic Club.—The subject for discussion at the next meeting, March 25th, will be “ On the Preparation of Lantern Slides.” This is a lantern night. Visitors are invited. Uo Uorrespondents. *,* We cannot undertake to return rejected communicaions; W. V. MORRIS.—1. The lens you have ordered will cover the plats somewhat better, as it will have a longer focus. As regard general qualities, the lenses are practically equal. 2. You can either get an outer box made to take the usual quarter-plate folding camera, or you can obtain a rigid box-camera. 3. It is a compromise with truth. J. H. (Glasgow).—There is no doubt as to the law on the point. If they are unfit for the purpose for which they are sold, the manu facturer is responsible for the loss; but, even assuming your case is good, to prove the facts to the satisfaction of a court might cost you several hundred times the value. R. S. P. E.—1. A rapid symmetrical or rectilinear by one of the high class makers is best, as it is almost impracticable to use a portrait lens for so large a. plate. If, however, you consider it essential to use a more rapid instrument, employ the small lens which you mention last, and enlarge the picture. Photo.—As you have only one print, you had better make the negative by copying it with the camera. W. B. (Cheadle).—The photograph you send is a very pleasing picture, and shows that you have made excellent progress in the time. We would suggest another view from the same standpoint when the light is brighter. N. GALLARD.- You probably refer to Mr. Pickwell’s photographic compass for registering a ship’s course. See PHOTOGRAPHIC News, vol, xxvii,, page 33. LMARCH 20, 1885. L. HAAKMAN.—Use the following toning bath, and fume your paper with ammonia. Chloride of gold 1 grain Whiting or chalk 30 grains Warm water Bounces Saturated solution of chloriic of lime ... 2 drops It is somtimes well to dilute this with its own bulk of water. T. E. Sansom.—To bleach the engraving, first soak it in warm water for a few minute 3, and then immerse it in a solution made by dissolving one ounce of commercial chloride of lime (bleaching powder) in four pints of cold water. When this solution has thoroughly penetrated the paper, ad I hydrochloric acid, a few drops at a time, until the print is sufficiently bleached. After each addition of hydrochloric acid the bath must be well agitated, and when the bleaching is over the print should be well washed, after which it ought to remain for about ten minutes in a solution containing one ounce of soda hyposulphite in four pints of water. F. L.—Lacquer prepared according to the following recipe will probably answer your purpose : — Shellac 70 parts Sandarac ' 10 ,, Mastic 5 ,, These are dissolved in 500 parts of methylated spirit. X. Y.—Dr. Stolze does not say what you suppose, but recommends first sensitizing the albumenized paper with a ten per cent, silver solution for four minutes. Draw over a rod, allow to drain, and then float the back of the paper for the same period upon the following: — Citrate of potash 1 part Water 30 parts T. Edge.—We should prefer to have one of about 12 inches focus, and in this case your arc may advantageously be 24 inches from the centre of the condenser, and your objective at the same distance on the other side Take care that the image of the arc falls exactly on the plane of the diaphragm of the objective. Focus by shifting the negative. A. M. S.—1. They are excellent, especially the cloud views. 2. It is, we think, in the exposure and development. The former should have been longer, and the latter more restrained. 3. Not having seen it, we cannot tell, but suppose it was done with a wide-angle lens. Chiaroscuro.—Give a very much longer exposure—four- or six fold. John Oxley.—The ugly view at the side is quite sufficient reason for using ribbed glass in this place, but as regards the smaller top light, you might do well to reconsider your determination-. Ribbed glass never gives so much light as clear glass, and is not very easy to clean. When the light requires softening, it is very easy to use a muslin screen or curtain. An angle of 45 degrees will be more suitable in your case. W. B. BLOXAM.—I. Your letter does not make it quite clear whether you have used it hot or cold. It should not be heated to a temperature over 120° F., and ought to be slightly alkaline. 2. You had better scrape it until an entirely fresh surface is ex posed. 3. It contains about half its weight of silver. G. C. F.—Immerse plain Saxe paper for five minutes in the follow ing solution :— Chloride of ammonium 100 grains Chloride of barium 100 ,, Citrate of soda 20 ,, Water 20 ounces When dry, sensitize on a bath made up of— Nitrate of silver 1 dram Water... ... 1 ounce he Ahotographit Uews. SUBSCRIPTIONS. Including Postage to any part of the United Kingdom:— Yearly ... 15s. Od | Half-Yearly ... 7s. 8d. | Quarterly ... 3s. 10d. To the United States, the Continent, and the Colonies: 1 — Yearly ... 17s. 4d. | Half-Yearly ... 8s. 8d. | Quarterly ... 4s. 4d To India (Yearly) 19s. 6d. ADVERTISEMENTS IN COLUMN. Not exceeding Five Lines (30 words)... 3s. 0d. Each Additional Line 0s. 4d. Repeated insertions, and special positions or style, by contract. Advertisements should be ferwarled (prepaid) to Piper and CARTER! 5, castle Street, Ilolborn, E.C., to reach the office not later than noon on Thursday. A fee of 6d. must be forwarded when the Publishers.grs expected' to receive and forward replies to Advertisements; and when the- undertake the receipt of replies, they must be entrusted with the naI and address of advertiser, for revelation to applicants, in case they m - deem it necessary.