Avogadro's law "P" are taken at standard conditions for temperature and pressure (STP), then "k"'=1/"n", where "n" is Loschmidt constant. Avogadro's hypothesis (as it was known originally) was formulated in the same spirit of earlier empirical gas laws like Boyle's law (1662), Charles's law (1787) and Gay-Lussac's law (1808). The hypothesis was first published by Amadeo Avogadro in 1811, and reconciled Dalton atomic theory with the "incompatible" idea of Joseph Louis Gay-Lussac that some gases were composite of different fundamental substances (molecules) in integer proportions. In 1814, independently from Avogadro, André-Marie Ampère published the same law with similar conclusions. As Ampère was
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