Joseph Louis Gay-Lussac
Joseph Louis Gay-Lussac (1778-1850), French chemist and physicist. In 1802 he demonstrated that all gases expand by the same fraction of their volume for the same increase in temperature. Subsequent researches with Alexander von Humboldt led to the discovery that water is composed of hydrogen and oxygen in the ratio 2:1; from this he formulated the law of volumes in 1808. Gay-Lussac also researched the properties of potassium and discovered the element boron.
