The photographic news

• Bandzählung: 11.1867
• Erscheinungsdatum: 1867
• 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-id1780948042-186700008
• PURL: http://digital.slub-dresden.de/id1780948042-18670000
• OAI: oai:de:slub-dresden:db:id-1780948042-18670000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

THE PHOTOGRAPHIC NEWS. Vol. XI. No. 440.—February 8, 1867. CONTENTS. PAGK Analysis of Developing Powders 61 Critical Notices 63 The Reason Why. By the Photographer’s Assistant 63 On the Employment of Carbolic Acid in Photography. By Dr. P. J. Kaiser 64 Raising the Prices of Portraiture 65 Prevention of Blisters in Collodio-Albumen Plates.—Iodide of Aluminum in Collodion 65 Brown Stains from Intensifying 66 Photography in China and Japan 66 PAGI Enlarging on Paper Prepared with Nitro-glucose 66 The Clouds. By Rev. II. J. Morton, D.D 68 Correspondence—Opal Printing Frames—Defective Cameras Sharpness and Hardness—Splitting of Negative Films Tone—Diffusion of Focus: A New Idea—A Drop towards Development—The Woodbury Process 69 Talk in the Studio 71 To Correspondents - 72 Photographs Registered 72 ANALYSIS OF DEVELOPING POWDERS. Some weeks ago we published the summarized result of an analysis of an organic developing powder. The analysis was made by Dr. Sehnauss, and published in detail in the PholographiscTies Archiv, and the remark was added that the developing powder was manufactured in England, and sold at three shillings and sixpence per pound. Whilst the genius of English photography and English photographers happily tends to openness and freedom of communication, and to the condemnation of secrets and nostrums, yet we do not regard secresy as to the preparation of trade articles as necessarily unfair or evil. It is undoubtedly desirable, in the practice of an art like photography, that the operator should know with what he is working, as such knowledge, if he be an educated photographer, will often modify his opera tions. Nevertheless, if a secret preparation be found to work well, there is no reason why its maker should not preserve his secret, and profit by the sale of his material. Here, as else where, the labourer is worthy of his hire, and if the mainten ance of a secret is necessary to securing that hire, no one can find fault. For this reason we should avoid publishing the result of any analysis of any popular trade preparation, or taking any steps to injure the sale or lessen the legitimate profits arising from the issue of such a preparation. In publishing the results of the analysis of Dr. Sehnauss, wo were not injuring any individual, inasmuch as no name accompanied the analysis, nor were any details of propor tions given. At the time we published the summary we had no idea whatever of the maker of the developing powder in question. We knew that several such powders had come before the photographic public during the year, some of which had been hawked from studio to studio by travelling vendors. The information, in its general form, being of interest to our readers, we gave it publicity, adding Dr. Sehnauss’ remark that it was found to work well. The following week wo received a letter from Mr. J. W. Ramsden, stating that the powder in question was his, denying the accuracy of the analysis of Dr. Sehnauss, and intimating that the Doctor appeared in a fair way to dis cover the mode of transmuting metals; intimating in such allusion, we presume, that his analysis indicated the presence of metallic salts which Mr. Ramsden did not use. In insert ing the letter, wc appended a note pointing out that as no maker’s name had been mentioned, nor anything published to indicate the identity of the powder analyzed with that of Mr. Ramsden, it was neither wise nor logical to claim the powder and dispute the correctness of the analysis. Wc hoped the matter was at an end, as the discussion of misunderstandings, however necessary at times, rarely tend to the edification of readers, and always cause discomfort to the Editor. Unfortunately, however, there is another gentle man concerned in Mr. Ramsden’s denial, the analyst whose results have been questioned. We have since received a letter from Dr. Sehnauss, who feels his honour and ability as a chemist impugned, and asks for further investigation. We publish his letter in the English dress in which we receive it: — “ To the Editor of the Photographic News, London. “ Jena, 24th January, 1867. “ Sir,—One of the last numbers of your Journal brought an observation referring to my analysis of an English deve loping powder, signed by Mr. Ramsden. As the same attacks my honour as a chemist, by representing therein my investigations to be a complete failure, I see myself com pelled to make a direct reply, and request you, therefore, to be so kind as to insert these lines in your Journal. Like wise, I should feel obliged by your having analyzed the by going [accompanying, we presume] powder by an experi enced chemist. The latter may either follow the process of my analysis or choose his own way ; however, the distillating of the powder must not be omitted to be done with diluted sulphuric acid, and then be sub jected to a thorough examina tion. That the said powder contains sulphate of copper will be clear to a dillisant by only looking at it. 1 can assure you, upon my honour, that the by-going powder is the same as has been sent to me for analyzation as an ‘English developing powder,’ by one of my German eminent friends, and which I have published in the photo graphic Archiv. Whether this powder has been composed by Mr. Ramsden himself I am at a loss to say. The said gentleman may very easily furnish me with a sample of his genuine powder, that I might analyze it. As I nave been informed, an English chemist is said to have only found in it sesquioxide of iron, which perhaps suits Mr. Ramsden better than my own closer analysis. “ I must confess myself that,on account of the complicated composition of the powder, I at first feared a mystification, as 1 have also mentioned to the sender of the powder.—I remain, sir, yours respectfully, Dr. J. Scuxauss." We feel it due to Dr. Sehnauss, as a German chemist who has made many interesting contributions to our art-science, to comply with his request. No powder, however, accom panied his letter, and we therefore selected some from a sample of Mr. Ramsden's, in our possession for analysis, and sent to Mr. Spiller, whose position as chemist and analyst in the Chemical Department of the Royal Arsenal places