Stanislao Cannizzaro in Italy. He is best known for his contribution to the then-existing debate over atoms, molecules, and atomic weights. He championed Amedeo Avogadro's notion that equal volumes of gas at the same pressure and temperature held equal numbers of molecules or atoms, and the notion that equal volumes of gas could be used to calculate atomic weights. In so doing, Cannizzaro provided a new understanding of chemistry. Stanislao Cannizzaro Stanislao Cannizzaro FRS (13 July 1826 – 10 May 1910) was an Italian chemist. He is remembered today largely for the Cannizzaro reaction and for his influential role in the atomic-weight
Gay-Lussac's law which he was the first to formulate (c. 1808). He is also sometimes credited, rightfully according to many modern scholars, with being the first to publish convincing evidence that shows the relationship between the pressure and temperature of a fixed mass of gas kept at a constant volume."" These laws are also known variously as the Pressure Law or Amontons's law and Dalton's law respectively. The law of combining volumes states that, when gases react together to form other gases, and when all volumes are measured at the same temperature and pressure The ratio between the volumes of the reactant