Calculation of percentages for purposes of First Schedule, and extended meaning of "substance" (物質)
(1) For the purposes of the First Schedule-
(a) in the case of liquid preparations, percentages shall be calculated on the basis that a preparation containing 1 per cent of any substance means a preparation in which 1 gram of the substance if a solid, or 1 millilitre of the substance if a liquid, is contained in every 100 millilitres of the preparation, and so in proportion for any greater or less percentage; and
(b) in the case of salts, percentages shall be calculated as in respect of the anhydrous base.
(2) The specification in paragraph 1 of Part I of the First Schedule of a substance shall, if the existence of isomers of that substance is possible within the specific chemical designation thereof, be taken to comprehend the specification of any isomer of that substance whose existence is possible as aforesaid; and any other reference in the First Schedule to a substance specified in paragraph 1 of Part I thereof shall be construed accordingly. [cf. 1965 c. 15 s. 24(2) U.K.]