Sir Joseph Wilson Swan (1828-1914) was a British chemist and inventor, who pioneered important developments in photography and electric lighting. Swan's active interest in using electricity for lighting had begun in about 1848, when he started experimenting with passing a current through a carbon filament in a vacuum. Later, he tried different filaments, including cotton thread treated with sulphuric acid. Only in the 1870s, however, did the development of a dynamo to produce a steady supply of current and a pump capable of producing a sufficiently high vacuum begin to make a really practical light bulb possible. In 1878 he demonstrated an electric light using a carbon wire in a vacuum bulb. Thomas Edison arrived independently at the same solution the following year. Edison had been more systematic in patenting his developments, however, and attempted to prosecute Swan for patent infringement. The action was defeated, and as part of the settlement the two men merged their production in the Edison and Swan United Electric Light Company in 1883. In that year, Swan improved the filament when he found a way of extruding nitrocellulose, which, treated with acetic acid, served as a filament and greatly lengthened the bulb's lifetime. In the early 20th century, this nitrocellulose fibre began to be exploited in textiles as an artificial silk. Swan was knighted in 1904.
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