Il y a cent ans : Jean-Baptiste Dumas et la Convention du Mètre

Abstract

A hundred years ago : Jean-Baptiste Dumas and the « Convention du Metre » . ; Dumas (1800-1884) is known as a great chemist, but at the end of his life, as Perpetual Secretary of the Paris Academie des Sciences, he played a very important part in the extension of the use of the Metric System. ; In 1869, he asked the French Government to convoke an International Commission to make a new standard metre. This Commission met in 1872 and called for a diplomatic Conference which took place in Paris in 1875 and in which Dumas worked as representative of France and also chairman of the scientists commission. He managed with much talent and patience the discussions which led to the signature, on May 20th 1875, by representatives of 17 States, of the « Convention du Metre » creating the International Bureau of Weights and Measures at the Pavillon de Breteuil near Sevres. ; In 1877, he became chairman of the French Section of the International Commission, working for the fabrication and calibration of the iridium-platinum new standards. ; In 1880, he became member of the International Committee of Weights and Measures and chairman of the new French National Bureau of Weights and Measures. The same year, with Broch, Stas and Mouchez, Dumas calibrated three kilograms and the weight of one of them was found so approaching the weight of the old standard that it was choosen to be the new International Standard Kilogram, still preserved in the Pavillon de Breteuil.