"(1) any person who sells to a person under the age of 18 years an article to which this section applies shall be guilty of an offence and liable on summary conviction to imprisonment for a term not exceeding 6 months, or a fine not exceeding level 5 on the standard scale, or both. (2) subject to sub-section (3) below, this section applies to - (a) any knife, knife blade or razor blade; (b) any axe, and (c) any other article which has a blade or which is sharply pointed and which is made or adapted for use for causing injury to a person. Sub-section 3 has exceptions which are not relevant to the present case. Sub-section 4 provides: "
"Knife. A cutting instrument consisting of a blade with a sharpened longitudinal edge fixed in a handle either rigidly, as in a table knife, carving or sheath knife, or with a joint, as in a pocket or clasp knife. The blade is generally of steel, but sometimes of other material, as in the silver fish and fruit knives, the blunt edged paper knife of ivory, wood, etcetera, and the flint knives of early man."