Dr William Walker James Nicol FRSE (1855 – 18 March 1929) was a Scottish chemist and photographer who invented the Kallitype printing process in 1889.
He was born in Edinburgh in 1855 the only son of Marianne Ballantyne and her husband, William Walker Nicol, both from the Scottish Borders.
He entered the University of Edinburgh in 1872 studying sciences and specialised in chemistry graduating with a BSc.
His proposers were Sir Peter Guthrie Tait, Alexander Crum Brown, Matthew Forster Heddle and Sir Peter Redford Scott Lang.
[4] He returned to Edinburgh around 1895 and lived at 15 Blacket Place, a neo-classical bungalow, in the south of the city.