While potash has been used since ancient times, it was not understood for most of its history to be a fundamentally different substance from sodium mineral salts.
wˌaɪl pˈɑːɾæʃ hˈæzbiːn jˈuːzd sˈɪns ˈeɪntʃənt tˈaɪmz, ɪt wʌz nˌɑːt ˌʌndɚstˈʊd fɔːɹ mˈoʊst əv ɪts hˈɪstɚɹi təbi ɐ fˌʌndəmˈɛntəli dˈɪfɹənt sˈʌbstəns fɹʌm sˈoʊdiəm mˈɪnɚɹəl sˈɔlts.