Bouvier (1856) "A declaration made according to law, before a competent tribunal or officer, to tell the truth; or it is the act of one who, when lawfully required to tell the truth, takes God to witness that what he says is true. It is a religious act by which the party invokes God not only to witness the truth and sincerity of his promise, but also to avenge his imposture or violated faith, or in other words to punish his perjury if he shall be guilty of it.
Among promissory oaths may be classed all those taken by public officers on entering into office, to support the constitution of the United States, and to perform the duties of the office.
Custom-house oaths and others required by law, not in judicial proceedings, nor from officers entering into office, may be classed among the assertory oaths, when the party merely asserts the fact to be true."
This is the oath for a commissioner of deeds for Kentucky in Louisiana. A commissioner of deeds functions as an out-of-state notary, certifying legal and business documents for individuals living abroad who have business in the state.
In form, oaths look much like affidavits. The oath-taker must state the venue for the act, the place and jurisdiction in which the oath is being taken. This is usually (though not in this case) followed by an “S.S.” or “Sct.” abbreviation for the Latin scilicet, meaning to wit or in particular, i.e. the state of Louisiana, city of New Orleans in particular.
The oath taker swears to faithfully exercise the powers of the office in a form provided by the constitution or legislation, and sign their name (if capable). In this example, the new commissioner has affixed the seal which he will use to certify official documents and affixed an example of his official signature. These were kept on hand by the Secretary of State to guard against counterfeit and forgery. Many commissioners of deeds served multiple states, and often had a single stamp made within which they could write in the name of the state on each document they certified.
The oath must be witnessed by an official with legal authority in that area, who signs a statement of the date and place of the oath and affixes their official title and (where possible) seal. In this case, following the capture of the city of New Orleans by United States military forces, the witnessing official is naval officer Captain James F. Miller, temporary mayor of the city. Miller signs both his naval rank and affixes the New Orleans mayor’s seal.