Sir John Herschel with cap, April 1867
by Julia Margaret Cameron
This man was/is truly amazing. Despite studying Art History and Photographic Theory for around 9 years, I’m only recently beginning to understand just how important Herschel is to everything I do. Fox Talbot, the ‘father of photography’ and main focus of many a Photographic Theory lecture, even needed Herschel’s help to learn how to fix a photograph onto paper. Herschel was also a total astronomy nerd.
I found a great piece on him, in William Crawford’s The Keepers Of Light: A history & working guide to early photographic processes:
"Herschel had discovered the use of sodium thiosulphate as a fixer. He was the first to employ the terms positive and negative to describe the steps in the photographic process. He was an early experimenter with photography on glass and he conducted a great many other photochemical investigations. Yet photography was only a minor part of this remarkable man’s work. His real fame was as an astronomer. Among his many achievements Herschel discovered 525 new stellar nebulae, made a chemical analysis of the solar spectrum, studied terrestrial magnetism, investigated the effect of the Earth’s orbit on climate and even managed to survive a photographic portrait session or two with the formidable Julia Margaret Cameron.
Herschel was also the first to discover the photosensitivity of ferric (iron) salts. On June 16th 1842, Herschel read to the Royal Society a paper entitled, ‘On the action of rays of the solar spectrum on vegetable colors and on some new photographic processes’. The new processes for which Herschel coined the names Cyanotype and Chrysotype, were mentioned only at the end. The first part of the paper was about flowers. Herschel had conducted a long series of experiments on the bleaching effect of light on the juices of various flowers. Later called Anthotype (from the Greek word for flower), these processes proved to be of no practical photographic value. In most cases it took weeks to complete a printing-out exposure on paper treated with juices from suitable plants (Herschel complained that the gloomy English weather of 1841 had delayed his experiments), and the resulting images were not permanent.”