ɪn nˈaɪntiːnhˈʌndɹɪd twˈɛnti θɹˈiː, kˈɛmɪsts dʒˈoʊhænz nˈɪkəlˌaʊs bɹˈɑːnstᵻd ænd tˈɑːməs mˈɑːɹtɪn lˈoʊɹi ˌɪndᵻpˈɛndəntli ɹˈɛkəɡnˌaɪzd ðæt ˈæsɪd bˈeɪs ɹɪˈækʃənz ɪnvˈɑːlv ðə tɹˈænsfɜːɹ əvə pɹˈoʊtɑːn.
In 1923, chemists Johannes Nicolaus Brønsted and Thomas Martin Lowry independently recognized that acid–base reactions involve the transfer of a proton.