Joseph Louis Proust published his Law of Definite Proportions (1 ene 1794 año – 31 dic 1794 año)

Descripción:

This law states that a compound is composed of exact proportions of elements by mass regardless of how the compound was created.
The Law of Constant Composition, discovered by Joseph Proust, is also known as the Law of Definite Proportions. ... The French chemist Joseph Proust stated this law the following way: "A chemical compound always contains the same elements combined together in the same proportion by mass."

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