S. 4 : Charge of income-tax-Capital or revenue-Income-Exemption from excise duty not under the purview of definition of income envisaged under S. 2(24)(xviii)-Such amount is thus not an income but capital receipt, not taxable under the Act-Entries in books of accounts not conclusive to determine income-No tax can be charged on an amount not actually earned.[S. 2(24)(xviii), 145]