TO PHOTOGRAPHERS, DAGUERREOTYPISTS, &c.--Instantaneous Collodion (or Collodio-Iodide Silver). Solution for Iodizing Collodion. Pyrogallic, Gallic, and Glacial Acetic Acids, and every Pure Chemical required in the Practice of Photography, prepared by WILLIAM BOLTON, Operative and Photographic Chemist, 146. Holborn Bars. Wholesale Dealer in every kind of Photographic Papers, Lenses, Cameras, and Apparatus, and Importer of French and German Lenses, &c. Catalogues by Post on receipt of Two Postage Stamps. Sets of Apparatus from Three Guineas. * * * * * COLLODION PORTRAITS AND VIEWS obtained with the greatest ease and certainty by using BLAND & LONG'S preparation of Soluble Cotton; certainty and uniformity of action over a lengthened period, combined with the most faithful rendering of the half-tones, constitute this a most valuable agent in the hands of the photographer. Albumenized paper, for printing from glass or paper negatives, giving a minuteness of detail unattained by any other method, 5s. per Quire. Waxed and Iodized Papers of tried quality. Instruction in the Processes. BLAND & LONG, Opticians and Photographical Instrument Makers, and Operative Chemists, 153. Fleet Street, London. *** Catalogues sent on application. * * * * * THE SIGHT preserved by the Use of SPECTACLES adapted to suit every variety of Vision by means of SMEE'S OPTOMETER, which effectually prevents Injury to the Eyes from the Selection of Improper Glasses, and is extensively employed by BLAND & LONG, Opticians, 153. Fleet Street, London. * * * * * PHOTOGRAPHY.--HORNE & CO.'S Iodized Collodion, for obtaining Instantaneous Views, and Portraits in from three to thirty seconds, according to light. Portraits obtained by the above, for delicacy of detail rival the choicest Daguerreotypes, specimens of which may be seen at their Establishment. Also every description of Apparatus, Chemicals, &c. &c. use in this beautiful Art.--123. and 121. Newgate Street. * * * * * IMPROVEMENT IN COLLODION.--J. B. HOCKIN & CO., Chemists, 289. Strand, have, by an improved mode of Iodizing, succeeded in producing a Collodion equal, they may say superior, in sensitiveness and density of Negative, to any other hitherto published; without diminishing the keeping properties and appreciation of half-tint for which their manufacture has been esteemed. Apparatus, pure Chemicals, and all the requirements for the practice of Photography. Instruction in the Art. THE COLLODION AND POSITIVE PAPER PROCESS. By J. B. HOCKIN. Price 1s., per Post, 1s. 2d. * * * * * PHOTOGRAPHIC CAMERAS. OTTEWILL AND MORGAN'S Manufactory, 24. & 25. Charlotte Terrace, Caledonian Road, Islington.