(2) Such profits or gains shall be computed after making the following allowances, namely : (i) . . . . . . . (ii) . . . . . . . (iii) . . . . . . . (iv) in respect of insurance against risk of damage or destruction of buildings, machinery, plaint, furniture, stocks or stores, used for the purposes of the business, profession or vocation, the amount of any premium paid; (v) in respect of current repairs to 'such buildings, machinery, plant, or furniture, the amount paid on account thereof; (vi) in respect of depreciation of such buildings, machinery, plant, or furniture being the property of the assessee, a sum equivalent to such percentage on the original cost thereof to the assessee as may in any case or class of cases be prescribed: (vii) in respect of any machinery or plant which has been sold or discarded, the amount by which the written down value of the machinery or plant exceeds the. amount for which the machinery or plant is actually sold or its scrap value: Provided that such amount is actually written off in the books of the assessee: Provided further that where the amount for which any such machinery or plant is sold exceeds the written down value, the excess shall be deemed to be profits of the previous year in which the sale took place; . . . . . . . . . . . . . . . ." 774 It is necessary to bear in mind the meaning and import of the provisions of section 10 (2)(vii)in so far as they apply to the present case.