Hall, James (1761-1832)
Scottish geologist, one of the founders of experimental geology. He provided evidence in support of the theories of Scottish naturalist James Hutton regarding the formation of the Earth's crust.
Hall was born in Berwickshire (Borders region) and spent much of the 1780s travelling in Europe. He undertook extensive geological observations in the Alps and studying Mount Etna in Sicily. He was also won over to the new chemistry of Antoine Lavoisier.
Hall set out to prove his friend Hutton's 'Plutonist' geological theories (the view that heat rather than water was the chief rock-building agent and shaper of the Earth's crust). By means of furnace experiments, he showed with fair success that Hutton had been correct to maintain that igneous rocks would generate crystalline structures if cooled very slowly. Hall also demonstrated that there was a degree of interconvertibility between basaltine and granitic rocks; and that, even though subjected to immense heat, limestone would not decompose if sustained under suitable pressure.