(b)the references to expenditure incurred on scientific research shall include all expenditure incurred for the prosecution, or the provision of facilities for the prosecution, of scientific research, but does not include any expenditure incurred in the acquisition of rights in, or arising out of, scientific research,and the references to scientific research related to a business or class of business shall include any scientific research—(i)which may lead to or facilitate an extension of that business or, all businesses of that class;(ii)of a medical nature which has a special relation to the welfare of workers employed in that business or, all businesses of that class;