The photographic news

• Bandzählung: 24.1880
• Erscheinungsdatum: 1880
• Sprache: Englisch
• Signatur: F 135
• Vorlage: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: SLUB Dresden
• Rechtehinweis: Public Domain Mark 1.0
• URN: urn:nbn:de:bsz:14-db-id1780948042-188000001
• PURL: http://digital.slub-dresden.de/id1780948042-18800000
• OAI: oai:de:slub-dresden:db:id-1780948042-18800000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Bemerkung: Exemplar unvollständig: Seite 1-82 in der Vorlage nicht vorhanden
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

Zlotes, Our readers will be glad to hear that the popular Pre sident of the South London Society, the Rev. F. F. Statham, is slowly recovering from the dangerous attack of bronchitis from which he has been suffering. The Woodbury type patent has lapsed after running the usual fourteen years. The invention was made the sub ject of a patent in 1865, and in January, 1866, we pre sented our readers with an illustration of the process. Photographers may sing the praises of gelatine and collo dion as much as they like, as the best vehicles for sensitive salts, there is evidently one branch of the art in which albumen—-that served for the first glass pictures ever made —still holds prominent rank. In micro-photography, Dr Regnaud has found, as other experimentalists have done before him, that the photographic image is never so fine and clear as when impressed upon an albumen plate. It is well to note that “ a Berlin-wool pattern ” of a pic ture is deemed, by the law of Great Britain, to be an infringement of copyright. The proprietor of Bow Bells has been sued for issuing a reproduction of this kind of Millais’ well-known painting of “ The Huguenots.” Those who make lantern transparencies by means of the carbon process—certainly one of the easiest means of pro ducing these charming pictures—will do well to employ only Indian ink tissue for the purpose. The difference in expense is altogether immaterial, and the transparency is sure to be free from accidental specks and points, which are so visible always in an enlargement. Mr. Henry Butter, the manager of the Royal Carriage Department, to whom photographers owe one of the most practical descriptions of the photo-lithographic process, has promised to re-write the details which appeared in our Year-Book of 1867, so as to bring them up to date. The memoir will shortly appear as one of our Topics. The story of the diamond making is a very brief one. A hydro-carbon gas—such as marsh gas, for instance, which is composed of hydrogen and carbon—is put into a stout iron tube of considerable thickness. A nitrogen compound —presumably cyanogen—is also introduced, with a view to the nitrogen combining with the hydrogen, and leaving the carbon free, for a diamond, as our readers are aware consists of pure crystallized carbon. The gas in the iron tube is subjected to enormous pressure to liquefy it, the tube being heated to aid in this work. The liquefaction of oxygen by Pictet, of Geneva, was effected by pressure in this way. The pure carbon passes under pressure from a gaseous into a liquid form, and finally crystallizes, in which condition it is found, upon the iron tube being opened. Ihe diamonds are, however, of the most minute character, and Mr. Hannay, of Glasgow, who has thus succeeded in making them, frankly owns that the game is not worth the candle. The note on “ Frilling,” by a well-known manufac turer of gelatine plates, which we publish in another column, will be welcome to many who are new to these films. By making up his pyrogallic solution with half water and half methylated spirit he ensures the gela tine from leaving the glass, should plates show signs of this defect before they are completely developed. The brown tint sometimes seen in fixed gelatine nega tives is due, according to Mr. Mayland, simply to the fact of the developing solution becoming exhausted. By employing a larger quantity of developer, the defect at once disappears. With two ounces of developer, for instance, let it remain ever so long in contact with the film, the brown tint is never got rid of, while on the employ ment, say, of four ounces, the negative, when placed against white note-paper, shows no trace of colour at all in the transparent portions. At the distribution of prizes at the Female School of Art, by the Baroness Burdett-Coutts, on Monday, we noted the presence of two young ladies, Miss Ethel Spiller and Miss Edith Robinson, daughters of gentlemen well known in the photographic world. Miss Spiller has been successful in securing the Gilchrist Scholarship, valued at £100. In a note on the researches of M. Stas into the various forms of silver bromide, of which an account will be found in another column, the Editor of the Photographisches Archio remarks that the results obtained by the dis tinguished Belgian savant throw great light on the theory of the preparation of emulsions. The special form or con dition of silver bromide most sensitive to the action of light seems to have been produced by M. Stas by means of boiling the ordinary salt in water for days together. Is there not something analogous to this in the long-continued cooking to which highly sensitive gelatino-bromide emul sion is submitted ? Further, may it not be possible to pro duce the sensitive bromide by boiling in water, and to make the emulsion by mixing the bromide thus prepared with the solution of gelatine ? The advantage of such an operation would be that the gelatine would preserve its power of setting quickly, which by the long emulsification it is apt to lose. Possibly, a similar method of proceeding would avail for making collodion emulsions. It would only be necessary to precipitate the silver bromide, to digest it for several days in boiling water, to separate the water by washing with alcohol, and finally to shake up the salt after this treatment with ordinary collodion. There seems reason to suppose that a process of this description would suffice to give us collodion emulsions greatly superior in sensitive ness to the ordinary wet plates, which compare so un favourably in that respect with the dry ones. Silver metallic stains upon gelatine negatives, of which many of our readers have complained, are easily removed by the application of a weak solution of cyanide of potas sium—say of three per cent, strength.