BLAND & LONG, Opticians, Philosophical and Photographical Instrument Makers, and Operative Chemists, 153. Fleet Street. * * * * * PHOTOGRAPHY.--HORNE & CO.'S Iodised 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. used in this beautiful Art.--123. and 121. Newgate Street. * * * * * PHOTOGRAPHIC PAPER.--Negative and Positive Papers of Whatman's, Turner's, Sanford's, and Cannon Frères' make. Waxed-Paper for Le Gray's Process. Iodized and Sensitive Paper for every kind of Photography. Sold by JOHN SANFORD, Photographic Stationer, Aldine Chambers, 13. Paternoster Row, London. * * * * * PHOTOGRAPHIC CAMERAS. OTTEWILL'S REGISTERED DOUBLE-BODIED FOLDING CAMERA, is superior to every other form of Camera, for the Photographic Tourist, from its capability of Elongation or Contraction to any Focal Adjustment, its extreme Portability, and its adaptation for taking either Views or Portraits. Every Description of Camera, or Slides, Tripod Stands, Printing Frames, &c., may be obtained at his MANUFACTORY, Charlotte Terrace, Barnsbury Road, Islington. New Inventions, Models, &c., made to order or from Drawings. * * * * * 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. * * * * * PHOTOGRAPHIC APPARATUS, MATERIALS, and PURE CHEMICAL PREPARATIONS. KNIGHT & SONS' Illustrated Catalogue, containing Description and Price of the best forms of Cameras and other Apparatus. Voightlander and Son's Lenses for Portraits and Views, together with the various Materials, and pure Chemical Preparations required in practising the Photographic Art. Forwarded free on receipt of Six Postage Stamps. Instructions given in every branch of the Art. An extensive Collection of Stereoscopic and other Photographic Specimens. GEORGE KNIGHT & SONS, Foster Lane, London. * * * * * {260} On Tuesday will be published, the Second Volume of