Joseph Gay-Lussac (1778-1850) was a French chemist and physicist. He pioneered investigations into the behavior of gases, established new techniques for analysis, and made notable advances in applied chemistry. The Gay-Lussac’s Law states that the pressure of a given mass of gas varies directly with the absolute temperature of the gas, when the volume is kept constant.
Joseph Gay-Lussac T-shirts at https://www.amazon.com/dp/B0CWK3XWSF