If a statutory enactment increases or decreases the term of imprisonment or the amount of the fine which may be inflicted for an existing statutory offence, is the new enactment retrospective so that a person who committed an offence before the passing of the amending legislation becomes subject to the new penalties, or does the new section apply only to offences committed after its passing ? One general principle as to the retrospective effect of legislation is thus laid down in Halsbury’s “Laws of England,” second edition, volume 31, at p. 513. “A statute is prima facie prospective and does not interfere with existing rights unless it contains express words, or there is the plainest implication to that effect. The fact of a statute being remedial, or designed to protect the public interest, is a matter to which great weight is to be attached and a different principle prevails where the statute is one that introduces a new remedy.” But there ar ....