| Year | Scientist | Discovery |
|---|---|---|
| 1662 | Robert Boyle | P inversely proportional to V at constant T |
| 1787 | Jacques Charles | V directly proportional to T at constant P |
| 1802 | Joseph Gay-Lussac | P directly proportional to T at constant V |
| 1811 | Amedeo Avogadro | Equal volumes contain equal molecules at same T, P |
| 1827 | Robert Brown | Brownian motion (random molecular movement) |
| 1848 | Lord Kelvin | Absolute temperature scale (0 K = -273.15°C) |
| 1857 | Rudolf Clausius | Kinetic molecular theory formal development |
| 1858 | James Clerk Maxwell | Distribution of molecular speeds |
| 1873 | Johannes van der Waals | Real gas equation correcting for molecular interactions |
| 1895 | Carl von Linde | Industrial gas liquefaction (Linde process, Joule-Thomson) |
Key insight: The ideal gas law PV = nRT was pieced together from four separate experimental laws over ~150 years before a theoretical (kinetic theory) foundation was provided by Clausius and Maxwell.