Lavoisier appears to have assumed that the composition of every chemical compound was constant, and the same opinion was the basis of much experimental inquiry at the hands of Joseph Louis Proust during 1801 to 1809, who vigorously combated the doctrine of Claude Louis Berthollet (Essai de statique chimique, 1803), viz.
The next advance was made by Joseph Louis Proust, whose investigations led to a clear grasp of the law of constant proportions.
ANTONIN PROUST (1832-1905), French journalist and politician, was born at Niort on the 15th of March 183 2.
The sugars obtained from honey were investigated by Lowitz and Proust, and the latter decided on three species: (I) cane sugar, (2) grape sugar, and (3) fruit sugar; the first has the formula C12H2201,, the others C 6 H 12 0 6.
JOSEPH LOUIS PROUST (1754-1826), French chemist, was born on the 26th of September 1754 at Angers, where his father was an apothecary.
Proust, on the other hand, maintained that compounds always contain definite quantities of their constituent elements, and that in cases where two or more elements unite to form more than one compound, the proportions in which they are present vary per sallum, not gradually.
Proust also investigated the varieties of sugar that occur in sweet vegetable juices, distinguishing three kinds, and he showed that the sugar in grapes, of which he announced the existence to his classes at Madrid in 1799, is identical with that obtained from honey by the Russian chemist J.
Proust among his pupils.
Proust (Paris, 1909); Madeira and the Canary Islands, by A.
Proust; but his speculations, in particular his insistence on the influence of the relative masses of the acting substances in chemical reactions, have exercised a dominating influence on the modern developments of the theory of chemical affinity, of which, far more than T.