Joseph Black, MD, FRSE, Scottish chemist, 1800.

Mezzotint engraving by J Heath after an original painting by Henry Raeburn of Joseph Black (1728-1799). Black was appointed Profesor of Anatomy and Chemistry at the University of Glasgow in 1756 and, in 1766, Profesor of Medicine and Chemistry at the University of Edinburgh. Whilst at Edinburgh, Black discovered the gas carbon dioxide, which he described as 'fixed air'. He is widely considered to be the 'father' of quantitative chemistry. He was a pioneer in the chemistry of gases and originator of the theory of specific and latent heat.