| || |
Daguerreotype of the Rosetta Stone taken in 1846
William Thomas Brande and Alfred Swaine Taylor Chemistry Second American Edition (Philadelphia: Henry C. Lea, 1867), Chapter XXXIX "Photography and its Applications", p.507.
Owing to the highly polished surface of the metal, the daguerreotype is admirably adapted to bring out the minutest details of objects. In 1846 we obtained by this process a copy of the 10,000 letters of the Greek inscription on the Rosetta stone of the British Museum, within the space of two square inches. The drawing is still preserved, and the Greek letters are easily legible by the aid of a lens. The process, however, has these disadvantages: the film is so thin that the polish of the silver prevents the image from being clearly seen in all lights; and, as with all silver-surfaces, the plate is exposed to tarnishing by sulphuration. These drawings, therefore, can only be preserved by completely preventing the access of air. The film of sulphide of silver, which after a time obscures the drawing, may, however, be removed by washing the plate with a weak solution of cyanide of potassium.
A daguerreotype "Copy of the Rosetta Stone" taken by John Jabez Edwin Mayall was included in a 1847 exhibition of Daguerreotypes in London.
(Accessed: 14 November 2015)