Hutton, Black and Watt: Science in Scotland

Scotland's Enlightenment produced major advances in natural science, often linked to practical improvement. The chemist Joseph Black identified 'fixed air', now known as carbon dioxide, in the 1750s, and developed the idea of latent heat, the heat absorbed or released when a substance changes state. James Watt, an instrument maker at the University of Glasgow, knew Black and in 1765 conceived the separate condenser, which made steam engines far more efficient.

The geologist James Hutton argued in a paper read in 1785 that rocks form through slow, repeated processes of erosion, deposition and uplift still at work today. At Siccar Point in 1788 he showed companions rock layers that implied immense spans of time, concluding that Earth showed 'no vestige of a beginning, no prospect of an end'. Hutton's 'deep time' challenged the common belief that Earth was only a few thousand years old. These men met in clubs and societies, showing how Enlightenment sociability linked theory, industry and science.