Boyle (1627-1691)
If the pressure on a confined gas is doubled, the volume of the gas is halved.
Graphically, as the volume increases, the pressure decreases, and vice versa. Temperature is assumed constant.
Boyle published "The Sceptical Chymist" in 1661; he used logic & experiments to support his ideas.
Boyle's combustion experiments:
most substances do not burn in a vacuum
gunpowder does ignite in a vacuum
metals heated in air filled, sealed, glass retorts form calxes (oxides); the metal calx weighs more than the original metal sample
Boyle explained the last result as due to "fire particles" entering the sealed glass retort.
Boyle also produced an inflammable gas (later called hydrogen).