Today is the birthday of Sir John Frederick William Herschel, 1st Baronet, born March 7, 1792 and died May 11, 1871. The son of astronomer William Herschel and Mary Baldwin, John Herschel was an accomplished scientist, mathematician and is considered one of the founding inventors of photography, a word he coined. A prolific and tireless worker, he was active in many diverse fields, from botany to astronomy-he named seven moons of Saturn and four moons of Uranus.
The word photography comes from two Ancient Greek words, phos (photos is the genitive form) meaning light-the source for words like photon and graphein meaning to write. The word photography actually has two modern etymologies: the word was coined in French in 1834 by Hercules Florence, five years before Herschel independently proposed it in English. Herschel decided on the terms positive and negative to describe the steps of early photography, and it was his early research and discovery of that sodium thiosulfate was a solvent of silver halides that led to the definitive discovery of photography twenty years later by Louis Daugerre and John Fox Talbot.
The photograph here of Herschel was taken in 1867, only 38 years after the discovery of photography, was taken by Julia Margaret Cameron, considered by many to be the first true ‘celebrity’ photographer.