Amedeo Avogadro

"...it was as though scales fell from my eyes, doubt vanished, and was replaced by a feeling of peaceful calm..."
                               -Lothar Meyer,
                                                                      upon hearing Avogadro's hypothesis

Time Period: 1776 - 1856

Background: Amedeo Avogadro was an Italian lawyer who turned to philosophy in spite of his successful legal career. He was demonstrator at the Academy of Turin, a professor of natural philosophy at the college of Vercelli, and first chair of mathematical physics in Italy at the University of Turin, where he stayed until his retirement in 1850.

Belief: During the middle years of Avogadro's life, when he was brilliant in his career in philosophy and science, the works and beliefs of Dalton was widespread in the scientific community. He analyzed Dalton's theory and found flaws (such as how he had confused the concept of atoms and molecules) and corrected them. With a newfound understanding of the atom-molecule concept, Avogadro went on to suggest that 'equal volumes of all gases at the same temperature and pressure contain the same number of molecules,' now known commonly as Avogadro's Principle.

Contribution: Avogadro's Principle is a tool today in determining atomic masses. He also established a number, Avogadro's Constant, 6.0221367 x 10^23, which is the number of molecules in one mole.