William Gregory (1803-1858), Scottish physician and chemist. Gregory studied at Edinburgh, graduating as a physician. As a chemist he studied with Liebig at Giessen. Gregory made advances in the chemistry of opiates, producing Gregory's Salt, a mixture of the hydrochlorides of morphine and codeine. He was instrumental in publicising Liebig's works by translating and editing them as well as maintaining his own work in organic chemistry. In later life he devoted himself to the study of diatoms. He also lectured on chemistry, holding positions in Glasgow, Dublin, Aberdeen and Edinburgh. Engraving based on a picture held by the Gregory family.