John Ferguson FRSE LL.D. (24 January 1838 – 3 November 1916) was a Scottish chemist and bibliographer. He is noted for the early alchemy and chemistry bibliography Bibliotheca chemica. He was generally nicknamed Soda Ferguson. A collection of 7,500 books and manuscripts, held by Glasgow University originally from his library, are known as the Ferguson Collection.
Ferguson was born on 24 January 1838 in Alloa, Scotland, the son of Adam Ferguson and Elizabeth Donaldson. He moved at an early age to Glasgow and attended Glasgow High School.
He graduated from the University of Glasgow with a BA in 1861 and an MA in 1862. In 1874 Ferguson was appointed the Regius Professor of Chemistry at the University of Glasgow, in place of Prof Thomas Anderson.
He was elected a Fellow of the Royal Society of Edinburgh in 1888. His proposers were Sir William Thomson (Lord Kelvin), James Thomson Bottomley, Peter Guthrie Tait and Alexander Crum Brown. St Andrews University awarded him an honorary doctorate (LLD).
Ferguson had an extensive library of books pertaining to alchemy, early chemistry, metallurgy, mineralogy, Paracelsus, the Romani language, the Rosicrucians, and witchcraft. In 1921 the University of Glasgow purchased about 11,000 of the books for the sum of £7000.