Albumen on Glass (Negative Process)
Introduced by Abel Niépce de Saint-Victor in 1848; this was the first successful photographic process on glass. The negatives showed very fine detail but exposure times were long which discouraged greater use.1 The advantage over the wet collodion process, introduced a few years later, was that it could be used dry and was therefore much easier to work with when travelling. That advantage was diminished when dry collodion processes were introduced in the mid 1850s, the process remained in commercial use for stereo diapositive and lantern slide production, especially for landscape and architectural work.
Albumen spread over the glass plate provided a carrier (binder) to hold the silver halide. The albumen used to coat the plate had to be made by the photographer, the solution was made by mixing together egg white, water and potassium iodide, this was beaten into a froth, filtered and coated on the glass plate, a plate whirler was sometimes used to force the liquid to the edges of the plate. When dry, the plate was sensitised with a silver nitrate/acetic acid solution (either in a dipping bath or a dish). It was then ready to be exposed. Development was with gallic acid and took around 20 minutes, the image was fixed in the normal way. Ground glass was sometimes used to give better adhesion for the albumen.
Exposure could be made whilst the plate was still moist, which improved its speed, or it could be dried in which case it remained usable for several days.
There were the usual variations to the process including its use in paper negatives. In 1851 Talbot patented a process, called Amphitype, which used a layer of albumen on glass, but was in other respects different to the process described here.2
This was a printing-out process introduced by Blanquart-Evrard in 1850. It largely replaced the plain salted paper (silver chloride) then in use and remained the most commonly used printing paper into the 1890s. The prints had a smooth glossy finish able to render much finer detail than plain salted paper, the gloss finish could be controlled by altering the amount of water mixed with the albumen or by double coating to increase the gloss. The prints were normally gold toned to overcome their natural reddish-brown colour and a yellow tint to the highlights that developed over time. Tinted paper was also available to combat the natural colour of the print.
Albumen solution was made by mixing together egg white, water and sodium chloride (other salts were also used), this was beaten into a froth and filtered. Paper was floated on the albumen mixture for around a minute or so and dried. The iodised paper was then sensitised by floating it on a dish of silver nitrate solution for around 6 minutes and dried. Albumen paper was at first coated by the photographer but could very soon be bought iodised needing only to be sensitised, later, from around 1870, it could be bought ready sensitised.
The fine detail reproduced by the albumen on glass process made it ideal for lantern slides and stereo transparencies.
References & Notes
Albumen on Glass: Robert Hunt, Photography on Glass, article in the Photographic Art Journal 1851, p. 233. Hunt, Man. Phot., p. 276. Hunt includes other sensitive salts in the process. Long, Practical Phot. (1856), p. 41. Sutton, article in Phot. Notes 17/8/1856, p. 133. Detailed descriptions of the process were in articles (reports of papers read before society meetings) in the Photographic News: by Mr. Cash 1/1/1857, p. 8, and James Ross (of Ross and Thompson) 1/2/1857, p. 45.
Albumen Prints: Hardwich, Phot. Chemistry, p. 187. Hunt, Man. Phot., p. 227. Brothers, History, p. 247. Price, Man. Phot. Manipulation, p. 211. Other ingredients such as serum of milk were sometimes included.
 For an open landscape in good light exposure times were in the order of 20 minutes, for a lightly coloured building around 5 minutes.
 BP 13664/1851.