Who was Joseph Louis Gay-Lussac in relation to Claude-Louis Berthollet?

Joseph Louis Gay-Lussac served as the research assistant to Claude-Louis Berthollet beginning in 1801.1

After graduating from the École Polytechnique, Gay-Lussac withdrew from the École Nationale des Ponts et Chaussées to join Berthollet at his private laboratory in Arcueil, France. This laboratory became the center of an influential private scientific society, and Gay-Lussac’s early scientific contributions were published as part of the society's memoirs. Under Berthollet’s mentorship and within this intellectual environment, Gay-Lussac conducted significant experiments on the properties of gases and other chemical phenomena.12