Sole Agents in the United Kingdom for VOIGHTLANDER & SON'S celebrated Lenses for Portraits and Views. General Depot for Turner's, Whatman's. Canson Freres', La Croix, and other Talbotype Papers. Pure Photographic Chemicals. Instructions and Specimens in every Branch of the Art. GEORGE KNIGHT & SONS, Foster Lane, London. * * * * * PHOTOGRAPHIC PAPER.--Negative and Positive Paper of Whatman's, Turners, Sanford's, and Canson Freres' 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 PICTURES.--A Selection of the above beautiful Productions (comprising Views in VENICE, PARIS, RUSSIA, NUBIA, &c.) may be seen at BLAND & LONG'S, 153. Fleet Street, where may also be procured Apparatus of every Description, and pure Chemicals for the practice of Photography in all its Branches. Calotype, Daguerreotype, and Glass Pictures for the Stereoscope. BLAND & LONG, Opticians, Philosophical and Photographical Instrument Makers, and Operative Chemists, 153. Fleet Street. * * * * * PHOTOGRAPHY.--Collodion (Iodized with the Ammonio-Iodide of Silver).--J. B. HOCKIN & CO., Chemists, 289. Strand, were the first in England who published the application of this agent (see _Athenaeum_, Aug. 14th). Their Collodion (price 9d. per oz.) retains its extraordinary sensitiveness, tenacity, and colour unimpaired for months: it may be exported to any climate, and the Iodizing Compound mixed as required. J. B. HOCKIN & CO. manufacture PURE CHEMICALS and all APPARATUS with the latest Improvements adapted for all the Photographic and Daguerreotype processes. Cameras for Developing in the open Country. GLASS BATHS adapted to any Camera. Lenses from the best Makers. Waxed and Iodized Papers, &c. * * * * * 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. used in this beautiful Art.--123. and 121. Newgate Street. * * * * *