Cannizzaro, Stanislao

Italian chemist

Born: Palermo, Sicily, July 13, 1826

Died: Rome, May 10, 1910

Lecoq De Boisbaudran

In his early life, Cannizzaro was involved in politics, but when a series of revolutions struck Europe in the 1840s, he fled to France. He returned to Sardinia, in north-west Italy, in 1851 and began his work with chemistry. The atomic theory of Dalton was widely accepted by then, but there was no agreed method on how atoms and molecules interacted, or how to use atomic weight in calculations, even though Berzelius had prepared an excellent table of atomic weights.

Finally, Kekule in desperation suggested a conference of important chemists from all over Europe to discuss the matter, and in 1860 an international scientific meeting was held for the first time in history. The conference was held in the the town of Karlsruhe in the tiny kingdom of Baden, and was attended by one hundred and forty delegates, including Bunsen and Mendeleev.

Cannizzaro also attended, bursting with missionary zeal. In 1858, he had come across Avogadros hypothesis, which had lain disregarded for a half century. He saw that the hypothesis could be used to determine the molecular weights, and hence the constitution, of various gases. Cannizzaro published a paper on the subject and went to the conference to do more. His speech convinced many of the attendees to adopt the proposed system and chemists moved steadily into complete agreement concerning the chemical formulas of the simpler compounds.

Later in life, Cannizzaro returned to politics and finally became vice-president of the Italian senate.

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