(1) Where a person -

(a) incurs capital expenditure on scientific research-

(i) other than on a building or structure, or

(ii) on any building or structure to the extent only that the construction or development of such building or structure is scientific research,

(b)

(i) is then carrying on a trade to which such expenditure relates, or

(ii) subsequently sets up and commences a trade which is related to such research,

(c) applies for an allowance under this subsection in respect of such expenditure, and

(d) so applies -

(i) in the case where the expenditure was incurred while carrying on the trade, within 24 months after the end of the chargeable period in which it was incurred, or

(ii) in the case where the expenditure was incurred before the setting up and commencement of the trade, within 24 months after the end of the chargeable period in which the trade was set up and commenced,