(1) For the purposes of the definition of scientific research, that definition shall, subject to subsection (2), be construed as including, and be deemed always to have included, a provision excluding from the meaning of that definition the following activities, that is to say:
(a) exploring for specified minerals,
(b) petroleum exploration, and
(2) As respects activities carried on before the 29th day of January, 1992, subsection (1) shall not have effect for the purpose of computing any charge to income tax or corporation tax on a person who has, before the 3rd day of December, 1991, made a claim in respect of expenditure incurred in exploring for specified minerals or in respect of petroleum exploration activities or in respect of petroleum extraction activities.
(3) In this section -
"the definition of scientific research" means the definition of scientific research as enacted in section 5 of the Finance Act, 1946, which definition was repealed and re