The Law of Conservation of Mass dates from Antoine Lavoisier's 1789 discovery that mass is neither created nor destroyed in chemical reactions. In other words, the mass of any one element at the ...

IT is a matter of very little importance whether Lavoisier actually obtained oxygen gas a few weeks or days before Priestley. The bare bald discovery of the gas is a very minor matter when placed ...

But beginning in the 17th century, a new era of scientific inquiry and discovery began to reveal ... he publishes his book on gases. 1772: Antoine Lavoisier and Joseph Priestley conduct ...