After returning to Britain, Playfair became manager of a calico works in Primrose, near Clitheroe, and in 1843 was appointed Professor of Chemistry at the Royal Manchester Institution, where he was assisted by Robert Angus Smith.

[2] In preparation for his lectures, Playfair toured France, Holland, Belgium, Germany, Austria and Scandinavia to study their education systems.

It aroused great public interest and Playfair later claimed that it gave a considerable impulse to technical education in Britain, with the government establishing the Department of Science and Art soon afterwards.

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.

[4] In 1868, Playfair was elected Liberal Member of Parliament for the Universities of Edinburgh and St Andrews, being sworn of the Privy Council[5] and made Postmaster General in Gladstone's government in 1873.

The Liberals lost power in early 1874 but on their return to office in 1880, Playfair was appointed Chairman of Ways and Means and Deputy Speaker of the House of Commons, holding these posts until 1883, when he was created a Knight Commander of the Order of the Bath.

[6] In November 1887, a meeting of the National Union of Conservative and Constitutional Associations held in Oxford passed a resolution calling for Fair Trade (a form of protectionism).

[10] Playfair delivered a speech to the City Liberal Club in London, where he claimed that economic depressions were not due to fiscal arrangements but were universal and synchronous in all industrialised nations.

The Liberal Party leader, William Ewart Gladstone, wrote to Playfair to thank him for his "admirable tract; so comprehensive, clear, simple in statement, rich in illustration".

He was further honoured when he was made a Knight Grand Cross of the Order of the Bath in 1895 and awarded the Harben Gold Medal from the Royal Institute of Public Health in 1897.