gay-lussac

< /ˈdʒoʊ zəf ˈlu i, -səf; French ʒɔˈzɛf lwi/, 1778–1850, French chemist and physicist.

noun

1. Joseph Louis (ʒozɛf lwi). 1778–1850, French physicist and chemist: discovered the law named after him (1808), investigated the effects of terrestrial magnetism, isolated boron and cyanogen, and discovered methods of manufacturing sulphuric and oxalic acids

1. French chemist and physicist who in 1808 developed a law governing the ratio of volumes of gases participating in chemical reactions. In that same year, with Louis Jacques Thénard, he discovered the element boron.