If the foregoing is not evidence sufficient, I have by me a very good glass positive of Hever Castle, Kent, which was taken in the spring of 1849, and two collodion negatives made by Mr. Archer in the autumn of 1848; and these dates are all vouched for by Mr. Jabez Hogg, who was Mr. Archer’s medical attendant and friend, and knew him long before he began his experiments with collodion—whereas I cannot find a trace even of the suggestion of the application of collodion in the practice [67] of photography either by Gustave Le Gray or J. R. Bingham prior to 1849; while Mr. Archer’s note-book proves that he was not only iodizing collodion at that date, but making experiments with paper pulp and gelatine ; so that Mr. Archer was not only the inventor of the collodion process, but was on the track of its destroyer even at that early date.
— from The Evolution of Photography With a Chronological Record of Discoveries, Inventions, Etc., Contributions to Photographic Literature, and Personal Reminescences Extending over Forty Years by Werge, John, active 1854-1890