" Section 12B which was introduced in the Indian Income tax Act, 1922 with effect from the 31st day of March, 1947, omitting parts not material reads as follows : "(1) The tax shall be payable by an assessee under the bead 'Capital gains ' in respect of any profits or gains arising from the sale, exchange or transfer of a capital asset effected after the 31st day of March 1946; and such profits and gains shall be deemed to be income of the previous year in which the sale, exchange or transfer took place (2) The amount of a capital gain ' shall be computed after making the following deductions from the full value of the consideration for which the sale, exchange or transfer of the capital asset is made, namely; (i) expenditure incurred solely in connection with such sale, exchange or transfer; (ii) the actual cost to the assessee of the capital asset, including any expenditure of a capital nature incurred and home by him in making any additions or alterations thereto, but excluding any expenditure in respect of which any allowance is admissible under any provision of sections 8, 9, 10 and 12.