CYANOGEN SOAP: for removing all kinds of Photographic Stains. Beware of purchasing spurious and worthless imitations of this valuable detergent. The Genuine is made only by the Inventor, and is secured with a Red Label bearing this Signature and Address, RICHARD W. THOMAS, CHEMIST, 10. PALL MALL, Manufacturer of Pure Photographic Chemicals: and may be procured of all respectable Chemists, in Pots at 1s., 2s., and 3s. 6d. each, through MESSRS. EDWARDS, 67. St. Paul's Churchyard; and MESSRS. BARCLAY & CO., 95. Farringdon Street, Wholesale Agents. * * * * * PHOTOGRAPHIC SOCIETY.--The Council will open in the beginning of January, at the rooms of the Society of British Artists, in Suffolk Street, Pall Mall, an exhibition of Photographs and Daguerreotypes. Coloured Pictures will not be excluded. It is recommended that all pictures sent should be protected by glass. No picture will be exhibited unless accompanied by the name and address of the Photographer or Exhibitor, and some description of the process employed. Pictures will be received at the Rooms in Suffolk Street, from Monday the 19th to Monday the 26th December. Further information may be obtained by application to the Secretary, R. FENTON, ESQ., 2. Albert Terrace, Albert Road, Regent's Park. * * * * * 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. * * * * * 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 INSTITUTION.--An EXHIBITION of PICTURES, by the most celebrated French, Italian, and English photographers, embracing Views of the principal Countries and Cities of Europe, is now OPEN. Admission 6d. A Portrait taken by MR. TALBOT'S Patent Process, One Guinea: Three extra Copies for 10s. PHOTOGRAPHIC INSTITUTION, 168. NEW BOND STREET. * * * * *