LIBRARIAN.--Wanted a Gentleman of Literary Attainments, competent to undertake the duties of Librarian in the Leeds Library. The Institution consists of about 500 Proprietary Members, and an Assistant Librarian is employed. The hours of attendance required will be from 10 A.M. to 8 P.M. daily, with an interval of two hours. Salary 120l. a year. Applications, with Certificates of Qualifications, must be sent by letter, post paid, not later than 1st December next, to ABRAHAM HORSFALL, ESQ., Hon. Sec., 9. Park Row, Leeds. * * * * * XYLO-IODIDE OF SILVER, exclusively used at all the Photographic Establishments.--The superiority of this preparation is now universally acknowledged. Testimonials from the best Photographers and principal scientific men of the day, warrant the assertion, that hitherto no preparation has been discovered which produces uniformly such perfect pictures, combined with the greatest rapidity of action. In all cases where a quantity is required, the two solutions may be had at Wholesale price in separate Bottles, in which state it may be kept for years, and Exported to any Climate. Full instructions for use. CAUTION.--Each Bottle is Stamped with a Red Label bearing my name, RICHARD W. THOMAS, Chemist, 10. Pall Mall, to counterfeit which is felony. CYANOGEN SOAP: for removing all kinds of Photographic Stains. Beware 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 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. *** Catalogues may be had on application. BLAND & LONG, Opticians, Philosophical and Photographical Instrument Makers, and Operative Chemists, 153. Fleet Street. * * * * * 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. * * * * *