If such deed be executed in a foreign country, it may be executed according to the laws of such country, and the execution thereof may be acknowledged before any notary public therein, or before any minister plenipotentiary, minister extraordinary, minister resident, charge d’affaires, commissioner, commercial agent, or consul of the United States appointed to reside therein, which acknowledgment shall be certified thereon by the officer taking the same, under his hand, and if taken before a notary public, his seal of office shall be affixed to such certificate.