THE PROCESS OF TALBOTYPE [FORMERLY CALLED CALOTYPE] PHOTOGENIC DRAWING, COMMUNICATED TO THE ROYAL SOCIETY, JUNE 10, 1841

[London]: Printed by J. & H. Cox, Brothers, 74 & 75, Great Queen Street, Lincoln's-Inn Fields, 1841. First edition. 4to., 4 pp. Aside from a few faint pinpoint spots of foxing, this is a fine, as new copy. Housed in a custom made cloth chemise and slipcase, titled in gilt along the spine. Shortly after the presentation of his paper before the Royal Society on 31 January, 1839, Talbot, at his own expense, printed the text as a pamphlet of 14 pages; "Some Account of the Art of Photogenic Drawing..."became the world's first separate publication on photography. Through this process, an ordinary piece of writing paper was immersed in a sensitizing solution, dried, placed in a camera and exposed in daylight to a subject for upwards of an hour or longer. Upon examination, a tonally reversed rendering of the subject was visible. It was then soaked in a solution of salt and washed and dried, then the process was essentially repeated exposing the first print to the new sensitized sheet, reversing the tones to produce an image with the tonality as in nature. Through a series of further experiments over the next months, Talbot discovered that a "latent" image always existed and that through chemical development, it could be brought to life. This allowed for speeding the exposure in the camera to be cut to a mere 30 seconds and the enriched chemical solutions would produce a sharper and tonally richer image. This process he first called the Calotype, from the Greek, kalos - beautiful.

On June 10, 1841, Talbot presented the Calotype process at a meeting of the Royal Society, and at his own expense, he published a four page description of his process. Unlike his earlier publication on Photogenic Drawing, here he states, in detail, the full process.
Upon the urging of John Herschel and David Brewster, he began to call his process, the Talbotype rather than Calotype. His intention was to license this process, and likely this printed description was printed to distributed to potential licensees.

Aside from changing the name from Calotype to Talbotype in the title of this publication, and the slight alteration in the printer's imprint, the text of the two issue are identical - the word Calotype remains in the body of the text This is the foundation stone of the negative-positive process that has been in use since it was first published.

This printing is much rarer than the Calotype variant, with WorldCat locating only Harvard University - Houghton Library, and Cornell University. Gernsheim Incunabula No. 655 listing only the Calotype variant. Roosens and Salu No. 10285, listing only the Calotype variant. Weaver, HENRY FOX TALBOT SELECTED TEXTS AND BIBLIOGRAPHY, No. 87, listing only the Calotype variant.