Joseph Priestley and Antoine Laurent Lavoisier
There are two pugilists in our second squabble. The English contender was Joseph Priestley - a minister of the church, a librarian and literary companion to the political aristocracy. On the French side, Antoine Lavoisier – wealthy son of a lawyer, social climber, tax collector and widely held to be the founder of modern chemistry.
In or around 1774 both men were working on a gas closely associated with combustion. Priestley called it "dephlogisticated air". Lavoisier named it oxygen.
Their research techniques were very different – while Priestley heated and sniffed, Lavoisier heated, weighed, measured and made calculations.
It could be said that though Priestley almost certainly isolated the gas first, Lavoisier understood it first. But the ruck didn't seem so simple during the late 1700's, when revolutions were overturning more than just chemical theories.
Lavoisier lost his head to Mme La Guillotine. Priestley lost his house to a rioting mob in the Midlands, and fled to America.