John Frederick William Herschel was born March 7, 1792 in Slough, Berkshire, and studied shortly at Eton College and St John’s College, Cambridge.
He took up astronomy in 1816, building a reflecting telescope with a mirror 18 inches in diameter and with a 20-foot focal length.
Herschel originated the use of the Julian day system in astronomy.
He also named the seven moons of Saturn and the four moons of Uranus.
In 1826, John was presented with the Gold Medal of the Royal Astronomical Society (which he won again in 1836), and with the Lalande Medal of the French Academy of Sciences in 1825, while in 1821 the Royal Society bestowed upon him the Copley Medal.
Herschel invented the actinometer in 1825 to measure the direct heating power of the sun’s rays, and his work with the instrument is of great importance in the early history of photochemistry.
John married Margaret Brodie Stewart on March 3, 1829 at Edinburgh and became the father of twelve children.
Herschel was made a Knight of the Royal Guelphic Order in 1831.
In 1836, Sir Herschel was elected a foreign member of the Royal Swedish Academy of Sciences.
John Herschel discovered sodium thiosulfate to be a solvent of silver halides in 1819, and informed Talbot and Daguerre of his discovery that this “hyposulphite of soda” (“hypo”) could be used to “fix” images and make them permanent.
Sir John Herschel in a lecture before the Royal Society of London, on March 14, 1839 made the word “photography” known to the world, completely unaware that the term photographie had already been coined by Hercules Florence in 1834.
Herschel derived the word “Photography” from the Greek word photos- for “light” and -graphos for “drawing”, thus “drawing with light.”
Then on August 9, 1839 after experimentally applying his “hypo” photographic fixer to glass, Sir John Herschel captured the first negative glass plate photograph.
Sir John Herschel went on to make numerous important contributions to photography.
He invented the cyanotype process and variations (such as the chrysotype), the precursors of the modern “blueprint” process.
He was the first to apply the terms “negative” and “positive” to photography.
He experimented with color reproduction, noting that rays of different parts of the spectrum tended to impart their own color to a photographic paper.
Herschel also made experiments using photosensitive emulsions of vegetable juices, called phytotypes and published his discoveries in the Philosophical Transactions of the Royal Society of London in 1842.
He collaborated in the early 1840s with Henry Collen, portrait painter to Queen Victoria.
Herschel originally discovered the platinum process on the basis of the light sensitivity of platinum salts, later developed by William Willis.
His ground-breaking research on the subject of photography was read at the Royal Society in London in March 1839 and January 1840.
John Herschel died May 11,1871 at the age of 79. He was given a national funeral and buried in Westminster Abbey.
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