Section 6. Whoever sells a cigarette, chewing tobacco, snuff or any tobacco in any of its forms to any person under the age of eighteen or, not being his parent or guardian, gives a cigarette, chewing tobacco, snuff or tobacco in any of its forms to any person under the age of eighteen shall be punished by a fine of not less than one hundred dollars for the first offense, not less than two hundred dollars for a second offense and not less than three hundred dollars for any third or subsequent offense.