Penalty for gaming in common gaming-house

Any person who shall have been concerned in gaming contrary to this Act, and who shall be examined as a witness before a Magistrate on the trial of any person for a breach of any of the provisions of this Act relating to gaming, and who upon such examination shall make true and faithful discovery to the best of his knowledge of all things as to which he shall be so examined, and who shall thereupon receive from the said Magistrate a certificate in writing to that effect, shall be freed from all prosecutions under this Act for anything done before that time in respect of such gaming.