The hydrogen requirement of Arrhenius and Brønsted–Lowry was removed by the Lewis definition of acid–base reactions, devised by Gilbert N. Lewis in 1923, – Table of discoveries attributes the date of publication/release for the Lewis theory as 1924. in the same year as Brønsted–Lowry, but it was not elaborated by him until 1938. Instead of defining acid–base reactions in terms of protons or other bonded substances, the Lewis definition defines a base (referred to as a Lewis base) to be a compound that can donate an electron pair, and an acid (a Lewis acid) to be a compound that can receive this electron pair.
THe HydRogen requiREmeNT oF ArRheNIus anD BrøNsteD–loWrY wAs rEmOved by THe lewIs definitIon Of ACid–base reAcTioNS dEvisED by GilBeRt N LewiS IN 1923 – table of DiscovERIES aTtributes the DAtE oF publiCAtioN/RelEase fOr tHe lewis theorY AS 1924 iN the same yEaR aS BRøNSted–lowry But it wAs not elaborAted BY him until 1938 instead Of defiNINg acid–bAsE reactIOnS in TerMs oF PROtons or otheR bonDed SubstAnces The lEwis deFINition defINeS a basE (rEfErREd To as a lewIs BasE) tO Be a compoUnd ThAt can DOnaTe an ELectron paiR anD aN AcId (a LeWis acid) to Be a compound that CAn reCeIve ThIs ELeCtron PaIr