In 1874, Englishman Richard Kennett was an amateur photographer working in the Maddox Street section of London. He had recently learned of fellow photographer John Burgess' emulsion that allowed photographers to prepare dry plates allegedly superior to the wet plates that were being produced at the time. Mr. Kennett believed he could improve upon the technique that Mr. Burgess produced to concoct his gelatine bromide emulsion, and performed a variety of his own experiments. One of the major issues with the Burgess emulsion was that the finished product did not last long. Therefore, in November 1873, Mr. Kennett took out a patent for a method that would enable an emulsion to be produced in both a dry and solid state that would last for a long time. He created a compound consisting of gelatine, bromide, chloride or iodide (preferably potassium, cadmium, or ammonium), and silver nitrate. After cleared of salts that formed while it was being mixed, the compound could be dried by heating it in flat dishes, creating a paste-like reduction. Upon cooling, the compound could be stripped from the dishes and placed to dry in a closet where dry air was constantly being circulated.
Mr. Kennett referred to his dried gelatine emulsion as a pellicle. Once the drying process was completed, a pellicle only needed to be dissolved into water to coat glass plates. However, there were several complaints from users that the pellicle produced thin images. This made Mr. Kennett's pellicle and dry plates an extremely hard sell. From 1874 to 1877, he embarked upon an exhaustive media campaign, which caught the attention of the Liverpool Dry Plate Company, which introduced Mr. Kennett's gelatine plates in 1876 and a more sensitive variation two years’ later.
Nevertheless, Mr. Kennett's gelatine process and dry plates were deemed a dismal failure. Ironically, it was the rapid drying of the plates that was responsible for their failure. Purchasers of the emulsion and plates would overexpose them considerably, which resulted in foggy plates and thin images. One user of the Kennett plates complained, "The difficulty we find is to prepare - or, rather, to dry - the plates as they have to be done with so small amount of light." Unfortunately, R. Kennett's dry plates did not generate the commercial and financial success he envisioned, and his name as well as his experiments have been largely forgotten. Nevertheless, Mr. Kennett's and his plates introduced Great Britain to a dry plate industry that became extremely lucrative for others (like Alfred Harmen and his Brittannia Works Company) and the development of machinery that could coat an astounding 12,000 plates daily.
2008 Encyclopedia of Nineteenth-Century Photography, Vol. I (New York: Routledge/Taylor & Francis Group LLC), p. 438.
1890 The Evolution of Photography (London: Piper & Carter), p. 610.
1888 A History of Photography (London: Trubner & Co.), pp. 66-68.
1874 The Photographic News for Amateur Photographers, Vol. XVIII (London: Piper and Carter), p. 610.
Copyright © 2002 - 2019 Historic Camera