 In 1671 , Robert Boyle discovered and described the reaction between iron filings and dilute acids , which results in the production of hydrogen gas . In 1766 , Henry Cavendish was the first to recognize hydrogen gas as a discrete substance , by naming the gas from a metal @-@ acid reaction " inflammable air " . He speculated that " inflammable air " was in fact identical to the hypothetical substance called " phlogiston " and further finding in 1781 that the gas produces water when burned . He is usually given credit for the discovery of hydrogen as an element . In 1783 , Antoine Lavoisier gave the element the name hydrogen ( from the Greek <unk> hydro meaning " water " and -γενής genes meaning " creator " ) when he and Laplace reproduced Cavendish 's finding that water is produced when hydrogen is burned . 
