Defended His Atomic Hypothesis Against Experimental Evidence

DALTON DEFENDED HIS ATOMIC HYPOTHESIS AGAINST EXPERIMENTAL EVIDENCE 

In 1808, the French chemist Joseph Gay-Lussac (1778—1850) reported thai when gaseous elements react, their volumes are in a ratio of small whole numbers. This is similar to what Proust described in his law of definite proportions except that Gay-Lussac was focusing on volume, not mass. Gay-Lussac s experiments showed that 2 liters of hydrogen completely reacts with 1 liter of oxygen (no more and no less) to form 2 liters of water vapor  

2 liters hydrogen gas + 1 liter oxygen gas — 2 liters water vapor 

In 1811, the Italian physicist and lawyer Amadeo Avogadro (1776—1856) gave a brilliant explanation for Gay-Lussac s experimental results. Avogadro hypothesized that the fundamental particles of hydrogen and oxygen were not atoms but rather diatomic molecules, where the term diatomic indicates two 

Burton S. Guttman, The Real Method of Scientific Discovery, Skeptical Inquirer 28(1), Jan./Feb. 45-47 

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