The photographic news

• Bandzählung: 12.1868
• Erscheinungsdatum: 1868
• 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-id1780948042-186800009
• PURL: http://digital.slub-dresden.de/id1780948042-18680000
• OAI: oai:de:slub-dresden:db:id-1780948042-18680000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

January 24, 1868.] THE PHOTOGRAPHIC NEWS. 41 cannot well be taught in books. Yet much may be taught by explanation of rules and elementary principles, and by examples of the application of these rules and principles. This is what we propose to do for our readers. Some years ago a very excellent series of papers on composition and chiaroscura, by Mr. Lake Price, appeared in these pages. Admirable, so far as they went, we have since discovered that, for many photographers, they scarcely went far enough, lacking something of the photographic application neces sary to give lessons their full value to photographic students. The material for a more extensive series of lessons, and of more especially photographic suggestion, has been for some time in preparation, contributions and suggestions for such a series having been offered by various of the ablest exponents of the art capacity of photography. Feeling that these lessons would acquire much additional value by being re-cast throughout by a gentleman whose education as a painter, and whose reputation and successful practice as an art photo grapher, would give weight and authority to his teachings, and by the original suggestion which such practice brings with it, we have induced Mr. H. P. Robinson to under take the task of preparing the series of papers on art which we have for some time promised our readers. Ho will take the accumulated materials from published and unpublished sources, and, bringing to bear his extensive practical knowledge of what belonging to pictorial effect is possible in photography, and how it may be best compassed, we believe we can promise our readers that which has been so long a desideratum—an essentially practical series of lessons in art as applicable in photography. The series will be illustrated by examples, selected either from the works of painters or photographers, and will bo produced by wood-engraving, photo-engraving, or any other process which shall be found best fitted for illustrating the purpose immediately in hand. The lessons will be commenced in our next. FARADAY AS A DISCOVERER. On Friday evening last, Dr. Tyndall delivered the first of two lectures upon the above subject to a very crowded and distinguished audience, at the Royal Institution in Albe marle Street. From the position occupied by Dr. Tyndall as brother professor at the Institution, and from his very intimate connection with Faraday during the later years of that philosopher’s life, no better or more suitable lecturer could have been chosen to do justice to the subject. The learned doctor prefaced his remarks by stating that, as the memoir he had prepared was a somewhat lengthy one, and it would be imposssible for him to read the whole of it in the two hours allotted to him for the task, he should be compelled to omit some considerable portion of it; the whole would, however, be printed and placed in the hands of the members in a short time. On Faraday’s parentage the lecturer touched but slightly, merely mentioning that he was decidedly of Carlyle’s opinion that a really able man was never born of stupid parents. He told the story of Faraday’s apprenticeship to a book binder, of his attending the lectures at the Royal Institution, of his making notes of these lectures and sending them to Sir Humphrey Davy, requesting employment in the labora tory of the Institution, of his engagement by Sir Humphry, and subsequent promotion to be assistant in the laboratory ; of his constant and unwearied investigations into the science of electricity, ending, in 1831, in his wonderful discovery that an electric spark could be produced from a magnet. In later years, when Faraday had arrived at the zenith of his fame, when he had followed up one discovery by another, and had achieved a series of the most glorious successes, the great man still liked to look back upon his earlier life, and delighted to visit the little workshop where, once upon a time, he toiled as a poor bookbinder’s apprentice. Although naturally of a sweet and gentle disposition, Faraday’s cha racter was by no means of a quiet and inexcitable nature, for his mind sometimes displayed an extraordinary amount of fire and energy, qualifications which were put to good use in the prosecution and elaboration of his laborious researches. After his triumphant discovery of the possi bility of deriving electricity from magnetism,—a discovery at present applied to many of our telegraph systems and to the production of the electric light,—Faraday turned his attention to the voltaic pile, and commenced a series of investigations producing results the novelty and unexpected character of which excited great interest in the scientific world ; pursuing his studies further, he sought to simplify the terms and symbols used in connection with electricity, and to lay down the theories deduced from his numerous experiments. Turning next to the subject of gravitation and cohesion, he occupied himself with investigating and following up the ideas of Newton, and in this branch of science he was not less successful in arriving at important results than heretofore. In the year 1840 Faraday’s health, which for many years had not been good, broke down com pletely, and he was compelled to seek relaxation from his labours in a visit to Switzerland ; in that country he resided for several months, and his diary kept during that period shows how pleasantly he passed his time, and how delighted the great yet simple philosopher felt when surrounded by the grandeous beauty of the Alps. The results of the researches undertaken by Faraday on his return to England will form the subject of the lecture this (Friday) evening. CYANIDE OF SILVER IN COLLODION. Mr. Bell, Photographer to the Army Medical Museum in the United States, communicates to our contemporary, the Philadelphia Photographer, his plan of using cyanide of silver to collodion for the double purpose of preserving it and preventing pinholes in the negatives, having used it long enough, he states, to be certain of its value for the purposes indicated. His method of working is as follows:— “ Dissolve in 2 ounces of water 100 grains of cyanide of potassium ; add to it a solution of nitrate of silver, 50 grains strong, until precipitation ceases; pour the precipitate into a filter, and wash well with water by percolation. Dry and bottle for use. Collodion. Ether ... ... ... ... 16 ounces Alcohol 16 „ Iodide of ammonium ... ... 160 grains Bromide of sodium ... ... 64 „ Cyanide of silver ... ... 5 „ Gun-cotton (Pary’s) 192 „ Mode of Preparation—No. 1. Take 8 ounces of the alcohol, dissolve in it 60 grains of the iodide of ammonium, add the cotton, shake well, then add the 16 ounces of ether, and shake until all are dissolved. No. 2. “ Into a mortar put the 64 grains of bromide of sodium, adding just enough water to dissolve it; then put in the 5 grains of cyanide of silver, granulate well together; add the 100 grains of iodide of ammonium, granulate, and finally add the 8 ounces of alcohol, granulate for ten minutes, then filter the solution into No. 1. Nitrate Bath. “ Forty grains of silver to the ounce, acidulated with nitric acid. “ The developer I prefer is Anthony’s, with a little modification: — Water 52 ounces Protosulphate of iron 3 „ Dissolve and add, drop by drop, a 10-grain solution of tannin in alcohol, until the iron solution is quite blue now add acetic acid 3 ounces, and 1 ounce of the gelatine syrup, and copper solution. Filter, and it is ready for use*