1850. "A Practical Treatise on Photography upon Paper and Gla.s.s," by Gustave Le Gray. Translated from the French by Thomas Cousins, and published by T. and R. Willats. This book is said to contain the first printed notice of collodion being used in photography.

-- R. J. Bingham, London, suggested the use of collodion and gelatine in photography.

-- M. Poitevin's gelatine process, published January 25th.

1851. Frederick Scott Archer published his collodion process in the March number of _The Chemist_, and introduced pyrogallic acid as a developer December 20th.

-- Fox Talbot announced his instantaneous process, and obtained, at the Royal Inst.i.tution, a copy of the _Times_ newspaper, while revolving rapidly, by the light of an electric spark.

-- Niepce de St. Victor's heliochromic process, published June 22nd.

Examples sent to the judges of the International Exhibition of 1862. See Jurors' Report thereon, pp. 88-9.

-- Sir David Brewster's improved stereoscope applied to photography.

1851. "Photography, a Treatise on the Chemical Changes produced by Solar Radiation, and the Production of Pictures from Nature, by the Daguerreotype, Calotype, and other Photographic Processes," by Robert Hunt. Published by J. J. Griffin and Co., London and Glasgow.

1852. "Archer's Hand-Book of Collodion Process." Published May 14th.

Second edition, enlarged; published 1854.

-- "Archer's Collodion _Positive_ Process." Published July 20th.

-- Fox Talbot's photo-engraving on steel process; patented October 29th.

1853. A Manual of Photography, by Robert Hunt, published.

-- Photographic Society of London founded. Sir Charles Eastlake, P.R.A., President; Roger Fenton, Esq., Secretary. First number of the Society's Journal published March 3rd.

-- Cutting's American patent for use of bromides in collodion obtained June 11th, and his Ambrotype process introduced in America.

-- "The Waxed-Paper Process," by Gustave Le Gray. Translated from the French with a supplement, by James How. Published by G. Knight and Co., Foster Lane, Cheapside.

-- Frederick Scott Archer introduced a triple lens to shorten the focus of a double combination lens.

1854. E. R., of Tavistock, published directions for the use of isingla.s.s as a subst.i.tute for collodion.

-- First series of photographic views of Kenilworth Castle, &c., from collodion negatives, published by Frederick Scott Archer.

-- Liverpool Photographic Journal, first published by Henry Greenwood, bi-monthly.

-- First roller-slide patented by Messrs. Spencer and Melhuish, May 22nd.

-- Fox Talbot first applied alb.u.men to paper to obtain a finer surface for photographic printing.

-- Photo-Enamel process; first patent December 13th.

-- Dry collodion plates first introduced.

1855. M. Poitevin's helioplastic process patented February 20th.

-- Dr. J. M. Taupenot's dry plate process introduced.

-- Photo-galvanic process patented June 5th.

-- "Hardwich's Photographic Chemistry." First edition, published March 12th.

-- Ferrotype process introduced in America by Mr. J. W. Griswold.

1856. "Photographic Notes." Edited by Thomas Sutton. Commenced January 1st; bi-monthly.

1856. Sutton's Calotype process, published March.

1856. Dr. Hill Norris's dry plate process. Patented September 1st.

1856. Caranza published method of toning silver prints with chloride of platinum.

1857. Moule's photogene, artificial light for portraiture. Patented February 18th.

-- Carte-de-visite portraits introduced by M. Ferrier, of Nice.

-- Kinnear Camera introduced. Made by Bell, Edinburgh.

1858. Pouncy's Carbon process patented April 10th.

-- Skaife's Pistolgraph camera introduced.

1858. J. C. Burnett exposed the back of the carbon paper and obtained half-tones.

-- Fox Talbot's photo-etching process, patented April 20th.

-- Paul Pretsch's photo-engraving process introduced.

-- "Sutton's Dictionary of Photography," published August 17th.

-- _The Photographic News_, founded, weekly. First number published September 10th, by Ca.s.sell, Petter, and Galpin, London.

-- "Fothergill Dry Process," by Alfred Keene, published August.

1859. Sutton's panoramic camera patented, September 28th.

-- Photo-lithographic Transfer process patented by Osborne, in Melbourne, Australia.

-- Wm. Blair, of Perth, secured half-tone in carbon printing by allowing the light to pa.s.s through the back of the paper on which the pigment was spread.

-- a.s.ser, of Amsterdam, also invented a photo-lithographic transfer process about this time.

1860. "Principles and Practice of Photography," by Jabez Hughes. First edition published; fourteenth edition, 1887.

-- Fargier coated carbon surface with collodion, exposed, and transferred to gla.s.s to develop.