“Certain rules to discover married couples in large societies or in public,” from The Meteor; or, General Censor, 1814:

1. If you see a gentleman and lady disagree upon trifling occasions, or correcting each other in company, you may be assured they have tied the matrimonial noose.
2. If you see a silent pair in a hackney or any other coach, lolling carelessly one at each window, without seeming to know they have a companion, the sign is infallible.
3. If you see a lady drop her glove, and a gentleman by the side of her kindly telling her to pick it up, you need not hesitate in forming your opinion; or,
4. If you see a lady presenting a gentleman with anything carelessly, her head inclined another way, and speaking to him with indifference; or,
5. If you meet a couple in the fields, the gentleman twenty yards in advance of the lady, who perhaps is getting over a stile in difficulty, or picking her way through a muddy path; or,
6. If you see a lady whose beauty and accomplishments attract the attention of every gentleman in the room but one, you can have no difficulty in determining their relationship to each other–the one is her husband.
7. If you see a gentleman particularly courteous, obliging, and good-natured, relaxing into smiles, saying smart things, and toying with every pretty woman in the room excepting one, to whom he appears particularly reserved, cold, and formal, and is unreasonably cross–who that one is nobody can be at a loss to discover; or,
8. If you see a young or an old couple jarring, checking, and thwarting each other, differing in opinion before the opinion is expressed; eternally anticipating and breaking the thread of each other’s discourse, yet using kind words, like honey-bubbles floating on vinegar, which soon are overwhelmed by the preponderance of the fluid; they are, to all intents, man and wife! it is impossible to be mistaken.

“The rules above quoted are laid down as infallible in just interpretation; they may be resorted to with confidence; they are upon unerring principles, and reduced from every day’s experience.”