Every person who was, during the previous year, a partner of a firm,and the legal representative of any such person who is deceased, shall be jointly and severally liable along with the firm for the amount of tax, penalty or other sum payable by the firm for the assessment year to which such previous year is relevant, and all the provisions of this Act, so far as may be, shall apply to the assessment of such tax or imposition or levy of such penalty or other sum.