Section 31: Protection of innocent sellers.

The sale by any person of any book, pamphlet, or other printed or written matter or, of any number or part of anyperiodical is not a publication thereof for the purposes of this Part, unless such person knows that such book pamphlet or written matter, or number or part, contains defamatory matter; or, in the case of any part or number of any periodical that such periodical habitually contains defamatory matter.