Wothlytype

Jacob Wothly, inventor of the Wothlytype

The Wothlytype was an alternative photographic printing process named after its inventor Jacob Wothly, in which a mixture of uranium ammonio-nitrate and silver nitrate in collodion formed a light-sensitive layer. It was a short-lived positive printing process proposed to remedy the recognised impermanence of albumen paper.

The printing-out-paper was superseded by collodio-chloride papers before the end of the 1860s.

Characteristics

The Wothlytype enabled positives to be made directly on paper, without an intermediate negative. The photographic emulsion consisted of a special uranium collodion that replaced the iodide, the chlorine or silver bromide. After exposure, the image was directly visible and was fixed immediately. Toning could be achieved in varying tones from deep blue-black to purple black. Efficiency and economy (avoiding the use of expensive silver) were advantages over competing processes. In addition, the collodion layer could also be transferred to ivory, wood, glass, porcelain and similar materials.

Procedure

First, the uranium collodion was applied to the paper, which was done with a brush, sponge or in a sensitizing bath, depending on the type of paper. After exposure, the images were immersed in an acidic bath for cleaning. The prints were washed to remove the acid, then immersed in a toning bath and then in a fixer. These two operations could also be combined. Finally, the images were washed a second time.

History

Wothly was a portrait photographer in business before 1853 and working in ambrotypes, whose studio was in Theaterplatz in Aachen. He went on in 1860 to make improvements to Woodward's solar camera. Even before Wothly, numerous photographers had tried to use uranium salts in photography without lasting success. Wothly in 1865 introduced his new uranium platinum collodion process for positive paper images, in which he used platinum and palladium compounds to reduce the uranium salt. The Wothlytype was patented in Germany, America (15 August 1865), Belgium (February 15, 1865/No. 17147), England, France (November 26, 1864), Portugal and Spain patentated. For France and Belgium, the Société française de Wothlytypie, founded specifically for this purpose by Emmanuel Mangel du Mesnil, took over licensing and distribution.

William Henry Fox Talbot shared his disappointment that the Wothlytype proved to suffer from fading.

Wothlytype was considered dangerous and controversial. Since Wothly suggested the use of the ingredients and spent years experimenting with improvements to his process, it is unclear whether Wothly's early death at the age of 50 was due to his experiments with this radioactive element or, as previously suspected, to the loss of his fortune following the bankruptcy of his banker. After Wothly's death in 1873, the Wothlytype disappeared from the market.

Danger to health

Uranyl nitrate is an oxidizing and highly toxic compound. When ingested, it causes severe chronic kidney disease and acute tubular necrosis and is a lymphocyte mitogen. Target organs include the kidneys, liver, lungs and brain. It also represents a severe fire and explosion risk when heated or subjected to shock in contact with oxidizable substances. After uranium was recognized as the cause of the so-called photographer's disease (nephritis and gastritis), this element was hardly ever used in photography.

Literature

• Jacob Wothly, Mangel du Mesnil: Application de nouveaux procédés photographiques, Paris, Siege de la société, 1865, volume 1, p. 47.

Web Links

• Detailed description of the "Wothlytype" in Photographic Correspondence, 1865, online
• Wothly and the Wothlytype in "Photographic Archive", 1864.