Changes

== History ==

== History ==

Although the existence of molecules was accepted by many chemists since the early 19th century as a result of [[John Dalton|Dalton's]] laws of Definite and Multiple Proportions (1803-1808) and [[Avogadro's law]] (1811), there was some resistance among [[logical positivism|positivists]] and physicists such as [[Ernst Mach|Mach]], [[Ludwig Boltzmann|Boltzmann]], [[James Clerk Maxwell|Maxwell]], and [[Willard Gibbs|Gibbs]], who saw molecules merely as convenient mathematical constructs. The work of [[Jean Perrin|Perrin]] on Brownian motion ([[1911]]) is considered to be the final proof of the existence of molecules.

Although the existence of molecules was accepted by many chemists since the early 19th century as a result of [[John Dalton|Dalton's]] laws of Definite and Multiple Proportions (1803-1808) and [[Avogadro's law]] (1811), there was some resistance among [[logical positivism|positivists]] and physicists such as [[Ernst Mach|Mach]], [[Ludwig Boltzmann|Boltzmann]], [[James Clerk Maxwell|Maxwell]], and [[Willard Gibbs|Gibbs]], who saw molecules merely as convenient mathematical constructs. The work of [[Jean Perrin|Perrin]] on Brownian motion ([[1911]]) is considered to be the final proof of the existence of molecules.