Recovery of previously allowed deductions treated as business income when original or successor obtains remission or benefit. Amounts or benefits subsequently obtained by the original assessee in respect of previously allowed losses, expenditure or trading liabilities are deemed profits and gains of business or profession and chargeable to tax in the year of receipt, regardless of whether the business continues; similarly, amounts or benefits obtained by a successor in business in respect of such items incurred by the first mentioned person are deemed business income and chargeable in the year received, with 'successor in business' defined to include amalgamated companies, persons succeeding to a business or profession, and succeeding firms.