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which occupied the last few years of his life. He was princi pally identified with the London Mechanics’ Institution, where his face was familiar to all the regular attendants of that Insti tution. In earlier times he occupied the post of assistant at the Royal Institution, and had the honour of aiding both Brande and Faraday in their work. ALBUArENIZED PAPER.—“ Three factories in the United States,” says the Scimtific American, “ consume nearly two million eggs a year, in making the peculiar kind of paper used by photo graphers known as albumen paper. ’ ’ Photogbaphic Club.—At the next meeting of this Club, June 6, the subject of discussion will be “On Out-door Por traiture.” O0 Cuxresggndents. Copyright.—1. There is no legal obligation to put “ registered ” on the photograph; but the circumstance of not doing so will often cause a magistrate to take an unfavourable view of an other wise good case. 2. As nearly as possible the same thing. 0. T.—1. Probably from the adhesion of air-bubbles to the paper during the process of sensitizing. 2. We are inclined to think they are iron stains; possibly the wet paper may have come in contact with iron or tin plate. Punch.—Write to Messrs. Siemens, Bros., 12, Queen Anne’s Gate, Westminster, or to the Edison LightingCompany, Ilolborn Viaduct, London. E. J. Ellery.—He would probably tell you to pack them more carefully. Instances in which well-packed photographs are injured during postal transmission are extremely rare. Triton.—If you are “ quite sure,” what is the use of our saying another word ? T. T.—1. “ Hardly ever.” 2. Captain Abney’s u Instruction ” is your best book, published at this office. W. T. Gordon.—The Photographic Society was formed in January, 1853. Emma.—See answer to T. T. ; also 11 Silver Printing” by Robin son and Abney. H. Spink.—1. We think the original suggestion is likely to explain the true cause, and the circumstance of the markings con stantly appearing in the same place seems to confirm this view. 2. Although we do not know of one at present, we will make enquiries. C. Hawkins (Bath).—This correspondent has forwarded a speci men of his Bijou note paper. The address occupies the usual place, while on the other side is a small oval portrait surrounded by a gilt wreath. W. H. C. Stiefel.—As the cotton dissolves, we may assume that either you used acids which were too weak, or that the cotton was damp. The sulphuric acid should be the ordinary strong acid of commerce ; and the nitric acid should possess a specific gravity not lower than 1*45, or the quantity of water must be somewhat reduced. The quantity of mixed acids referred to will serve to efficiently nitrate 150 grains of cotton. 2. From 35 to 40 grains of nitrate of silver to each ounce of water. 3. The first formula on p. 199. 4. Alcohol of 96 per cent, will answer very well. J. Kay.—We have a letter awaiting you at our office. Please forward address. L. Burel.—1. The sample of paper which you sent consists princi pally of wood pulp, and we have little doubt that it will gradually darken upon exposure to light. 2. It is easily decomposed, even by very weak acids, and if not properly protected against the action of the air, it will become useless. 3. Bichromate of potash is not to be recommended for the purpose, as it is extremely poisonous. 4. A moderate course is best, as otherwise the fibrous material is itself attacked, and much mischief may result. B. C. L.—1. Not unless a considerable excess of acetic acid is pre sent. 2. Make a solution of masticated india-rubber in benzole, this solution being a little more viscous than ordinary collodion. Coat the negative with this, and when dry, apply collodion in the usual way, after which the rubber solution and collodion are to be poured on alternately until a sufficient thickness is built up. Beginner.—1. Look well to your camera, dark slides, and lens mounts, with a view of ascertaining whether any light enters through previously unobserved openings. 2. Use about half the quantity of ammonia. Nitrate. —1. Water obtained by the condensation of the waste steam of an engine is generally unfit for the purpose, ns it con tains certain volatile oily products. 2. A much weaker developer will suit your work better; but you must considerably increase the time of exposure. 3. It is practically insoluble in water, but appreciably soluble in a solution of common salt. Francis Pollard.—We know of nothing of the kind at Basel ; but a school exists at Salzburg. Write to the Herr Director, Photographisches Unterichts-Atelier, Salzburg. *,* Erratum.—In our issue of May 18, by a stupid slip of the pen, we give Southampton as the next meeting place of the British Association; of course it should have been Southport, THE EVERY-DAY FORMULARY. The GELATINO-BROMIDE PROCESS. Emulsion.—A—Nit. silver 100 grains, dist. water 2 oz. B Bromide potassium 85 grains,Nelson’s No. 1 gelatine 20 grains, dist. water 12 oz.. a one per cent, mixture of hydrochloric acid and water 50 minims. C—IC dide potassium 8 grains, dist. water oz. D—Hard gelatine 120 grains, water several oz. When the gelatine is thoroughly soaked, let all possible water be poured off D. A and B are now heated to about 120° Fahr., after which B is gradually added to A with constant agitation; C is then added. Heat in water bath for half an hour, and stir in D. After washing add oz. alcohol. Pyro. Developer. —No. 1—Strongliq. ammonia 13 oz., bromide potas sium 240 grains, water 80 oz. No. 2—Pyro. 30 grains, water 10 oz. In case of an ordinary exposure mix equal vol. Iron Developer.—Potassium oxalate sol. (1 and 4) 80 parts, ferrous sulphate sol. (1 and 4) 20 parts, dist. water 20 parts. To each 4 oz. of the mixed developer add from 5 to 30 drops ten percent, sol. potassium bromide, and 30 drops sol. sodium hyposulphite (1 and 200). Substratum or Preliminary Preparation.—Soluble silicate of soda 1 part, white of egg 5 parts, water 60 parts. Beat to froth and filter. Fixing.—Sat. sol. of sod. hypo. 1 pint, sat. sol. of alum 2 pints, mixed. Cowell’s Clearing Solution.—Alum 1 part, citric acid 2 parts, water 10 parts. Edwards makes this sherry coloured with perchloride iron. Eder’s Method of Intensification.—The negative is whitened by soaking in sat. sol. of mercuric chloride, and after thorough rinsing immersed in potass, cyan. 10 parts, potass, iod. 5 parts, mercuric chloride 5 parts, water 2,000 parts. As film becomes dark brown, the actinic opacity is increased; but prolonged action causes brown tint to become lighter, until at last the negative is no denser than at first. Fol’s Backing Sheets.—A chromographic paste is prepared with gelatine 1 part, water 2 parts, glycerine 1 part, and a very small addition of Indian ink. Strong paper or shirting is coated, and the sheets are laid, face downward, on waxed glass to set. Press to back of glass plate. The Wet Collodion Process; The Nitrate Bath.—Water 14 oz., nit. silver 1 oz„nitric acidl drop. Before using coat a small plate, and immerse it for 20 minutes. Cleaning Preparation for New Plates.—Alcohol 4 oz., Jewel ler’s rouge -oz., liquid ammonia 2-oz. Film-removing Pickle for Old Plates. —Water 1 pint, sulphuric acid 4 fluid oz., bichromate potassium 4 oz. Substratum.—Whites of 2 eggs well beaten, G pints of water, and 1 dr. liq. ammon. Negative Collodion for Iron Development.—Alcohol 1 pint, pyroxylin© of suitable quality 250 grains, shako well and add ether 2 pints. Iodize this by mixing with one-third of its volume of alcohol ] pint, iod. ammon. 80 grains, iod. cadm. 80 grains, brom, ammon. 40 grains. Normal Iron Developer.—Water 10 oz:, proto-sulphate iron } oz., glacial acetic acid | oz., alcohol i oz. The amount of proto-sulphate iron may be diminished to 4 oz. when full contrasts are desired, or increased to 1 oz. when contrasts are unduly marked. With new bath quantity of alcohol may be reduced to ,| oz.; but when bath is old more is wanted. Intensifying Solution.—Water 6 oz., citric acid 75 grains, pyro. 30 grains. When used, add a few drops of the silver bath to each ounce. Lead Intensification.—After neg. washing, immerse in dist. water 100 parts, red pruss. potash 6 parts, and nit. lead 4 parts. When it is yellowish white wash and immerse in liquid sulphide ammon. 1 part, water 4 parts. Fixing Solution.—1. Potass, cyanide 200 grains, water 10 oz. 2. Sat. sol. of sod. hypo. Varnish.'—Shellac 2 oz., sandarac 2 oz., Canada balsam 1 dr., oil of lavender 1 oz., alcohol 16 oz. Printing Processes. Albumen Mixture for Paper.—White of egg 18 oz., 500 grs. ammon. chlor, in 2 oz. of water. Beat to a froth, stand, and filter. Sensitizing Solution. —Nit.silver 50grs., water 1 oz., sod. carb. Jgr. Acetate Toning Bath.—Chi. gold 1 gr., acet, soda 20 grs.. water 8 oz. Lime do.—Chi. gold 1 gr., whiting 30 grs., boiling water 8 oz., sat. sol, chi. lime 1 drop. Filter cold. Bicarbonate do.—Chi. gold 1 gr., bicarb, soda 3 grs., water 8 oz. Fixing Bath. —Sodium hypo. 4 oz., water 1 pint, liq. ammon. 30 drops. Reducer for Deep Prints.—Cyan, potass. 6 grs., liq. ammon. 5 drops, water 1 pint. Encaustic Paste.—Best white wax 1 oz., oil of turpentine 5 oz. Sensitizing Bath for Carbon Tissue.—Bichromate potash 14oz., water 30 oz., ammonia 1 dr., methylated spirit 4 oz. Enamel Collodion. -Tough pyroxyline 120 grs., methylated alcohol 10 oz., ether 10 oz., castor oil 20 drops. Mountant.—1. Fresh solution of best white gum. 2. Fresh starch. Collotypic Substratum.—Soluble glass 3 parts, white of egg 7 parts, water 10 parts. Collotypic Sensitive Coating.—Bichromate potash ] oz., gela tine 22 oz., water 22 oz. Collotypic Etching Fluid.—Glycerine 150 parts, ammonia 50 parts, saltpetre 5 parts, water 25 parts. Printing on Fabric.—Remove all dressing from fabric by boiling in water containing a little potash, dry, and albumenize with ammonium chloride 2 grammes, water 250 cubic cents., and the white of 2 eggs, all being well beaten together. A 70-grain silver bath is used, and the remain ing operations are as for taper. Cyanotype Printing.—Water 1 oz., red prussiate of potash (ferri cyanide) 1 dr., ammonio citrate of iron 1 dr. Prepare and preserve in the dark. Float the paper and dry. Fixation by mere soaking in water. Various. Luckardt’s Retouching Varnish.—Alcohol 300 parts, sandarac 50 parts, camphor 5 parts, castor oil 10 parts, Venice turpentine 5 parts. Matt Varnish.—Sandarac 18 parts, mastic 4 parts, ether 200 parts, benzole 80 to 100 parts. Encaustic Paste.—Best white wax,in shreds. 1 oz., turpentine 5oz.; dissolve in gentle heat, and apply cold with piece of flannel. Ferrotypes. Collodion.—Ammonium iodide 35 grains-, cadmium iodide 25 grains, cadmium bromide 20 grains, pyroxyline 70 grains, alcohol 5 oz., ether 5 oz. Bath.—Silver nitrate 1 oz., water 10 oz., nitric acid 1 drop. Developer.—Ferrous sulphate 1 oz., glac. acetic acid 1 oz., water 16oz. Fixing and Varnish,—Same as wet collodion process.