38. Where, for any assessment year, the net result of the computation of income under the head “Income from business or profession” is a loss to the assessee, not being a loss sustained in a speculation business, and such loss has not been wholly set off under section 37, so much of the loss as has not been so set off, the whole of the loss, where the assessee has no income under any other head or has income only under the head “Capital gains”, shall be carried forward to the next following assessment year, and-(a) it shall be set off against the income, if any, from the business or profession for which the loss was originally computed if such business or profession continued to be carried on by him in the income year; and(b) if the loss cannot be wholly so set off, the amount of the loss not so set off shall be carried forward to the next assessment year and so on for not more than six successive assessment years.