He ascended to a height of over 23,000 feet in a balloon to  conduct atmospheric investigations in 1804, co-discovered boron 
He ascended to a height of over 23,000 feet in a balloon to  conduct atmospheric investigations in 1804, co-discovered boron  with Thenard in 1808, and rediscovered Charles' Law. He also  formulated two laws sometimes named for him: that the pressure of a  gas is directly related to pressure, and that gases combine  chemically in simple ratios by volume. FTP, name this early  nineteenth century French chemist.
He ascended to a height of over 23,000 feet in a balloon to  conduct atmospheric investigations in 1804, co-discovered boron  with Thenard in 1808, and rediscovered Charles' Law.
Joseph Louis {Gay-Lussac}