4. Section 3 of the Principal Act is amended—
(a) by omitting from subsection (1) the definitions of “drug of dependence” and “prohibited substance” and substituting the following definitions respectively:
“ ‘drug of dependence' means a substance specified in Column 1 of Schedule 1 to the Drugs of Dependence Regulations;
‘prohibited substance' means a substance specified in Column 1 of Schedule 2 to the Drugs of Dependence Regulations, or a drug analogue;”; and
(b) by omitting from subsection (3) “, except in Schedule 1, 2 or 3,”.