Joule-thomson effect

The Joule-Thomson effect demonstrated how a gas cools when it expands if kept insulated from external energy sources. This effect later facilitated the liquefaction of permanent gases.
 James Prescott Joule and William Thomson England 1852 Joule-thomson effect

The Joule-Thomson effect demonstrated how a gas cools when it expands if kept insulated from external energy sources. This effect later facilitated the liquefaction of permanent gases.