Whenever the Commissioner becomes cognizant of any violation of any of the provisions of this article, he shall immediately notify in writing the manufacturer, importer, jobber or dealer, if known. Any party so notified shall be given an opportunity to be heard under such regulations as may be prescribed by the Commissioner. If it appears that any of the provisions of this article have been violated, the Commissioner shall certify the facts to the solicitor in the district in which the sample was obtained and furnish that officer with a copy of the result of the analysis or other examination of the article, duly authenticated by the analyst or other officer making such examination under the oath of such officer. In all prosecutions arising under this article the certificate of the analyst or other officer making the analysis or examination, when duly sworn to by such officer, shall be prima facie evidence of the facts therein certified.