The proviso to subsection (2) of section twenty-seven of the Finance Act, 1946 (which, amongst other things, prevents certain pensions payable under the National Insurance Act from being treated as earned income for the purposes of the increased personal allowance by reference to the wife's earned income provided for by subsection (2) of section eighteen of the Finance Act, 1920) shall not apply to any payment by way of retirement pension under the National Insurance Act (as defined in the said section twenty-seven), being a pension payable to the wife by virtue of her own insurance.