H. C. C. (Devizes). _The failure in the picture sent has the appearance of having been caused by air-bubbles in the solution when exciting the albumenized paper._ _We hope next week to present our photographic readers with a very simple mode of preparing paper for the Talbotype process. In the mean time we can assure them of the beautiful results we have seen produced by Mr. Lyte's process in the present Number. Let those who try it remember, however, that by how much more rapid is the action, by so much more care is required in the operation, and so much greater is the risk of failure._ "NOTES AND QUERIES" _is published at noon on Friday, so that the Country Booksellers may receive Copies in that night's parcels, and deliver them to their Subscribers on the Saturday_. "NOTES AND QUERIES" _is also issued in_ Monthly Parts, _for the convenience of those who may either have a difficulty in procuring the unstamped weekly Numbers, or prefer receiving it monthly. While parties resident in the country or abroad, who may be desirous of receiving the weekly Numbers, may have_ stamped _copies forwarded direct from the Publisher. The subscription for the stamped edition of_ "NOTES AND QUERIES" _is eleven shillings and fourpence for six months, which may be paid by Post-Office Order, drawn in favour of the Publisher_, MR. GEORGE BELL, No. 186. Fleet Street. * * * * * 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. 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. * * * * *