ANDREWS , THOMAS

The son of a linen merchant from Belfast (now in Northern Ireland), Andrews studied chemistry under Thomas Thomson at Glasgow, under Jean Dumas in Paris, and under Justus von Liebig at Giessen. He also studied medicine at Edinburgh and obtained his MD in 1835. He practiced medicine in Belfast before becoming vice-president of Queen's College, Belfast, in 1845 and professor of chemistry in 1849.

Andrews made experimental studies on the heat evolved in chemical reactions and also showed that ozone is an allotrope of oxygen. He was a brilliant experimentalist and his work on the liquefaction of gases brought order to a confused subject. Andrews performed a famous series of experiments on the variation of the volume of carbon dioxide gas with pressure. He studied the behavior of the gas at different temperatures, and showed that there was a certain temperature – the critical temperature – above which the gas could not be liquefied by pressure alone. This work, which was published as On the Continuity of the Liquid and Gaseous States of Matter (1869) led to the liquefaction of those gases previously held to be ‘permanent’ gases.