John Herschel, 1792 – 1871, was an English polymath, mathematician, astronomer, chemist, inventor, and experimental photographer. Herschel’s Preliminary Discourse (1831), which advocated an inductive approach to scientific experiment and theory-building, was an important contribution to the philosophy of science.
Hershel was interested in the properties of light. In 1819 Herschel discovered that hyposulfite of soda could dissolve photosensitive silver salts, and twenty years later he came up with his own negative-positive process using sensitized paper. Hershel called these images “photographs”. Herschel shared his findings with William Henry Fox Talbot and Louis Dageurre, but deferred to Talbot in publishing this discovery.
The first public discourse on ‘photographic drawing’ was given by John Hershel on the 14th March 1839:
Herschel and one of his first ‘negatives’ was of his telescope:
This ‘negative’ is another of Herschel’s first photographs: