Appointed a Companion of the Order of the Bath, Playfair also became Gentleman Usher to Prince Albert, and in 1853 was appointed Secretary of the Department of Science, in which capacity he advocated the use of poison gas against the Russians in the Crimean War. In 1855, he was a commissioner of the Exposition Universelle, and two years later became President of the Chemical Society, finally returning to Edinburgh University in 1858 as Professor of Chemistry there. In 1859 he was elected a Fellow of the Royal Society of Edinburgh, his proposer being James David Forbes. He served as the Society's Vice President from 1864 to 1870.