The Ladies' Book of Etiquette, and Manual of Politeness

Do not look round the house with your glass. A lady's deportment should be very modest in a theatre. Avoid carefully every motion, or gesture that will attract attention. To flirt a fan, converse in whispers, indulge in extravagant gestures of merriment or admiration, laugh loudly or clap your hands together, are all excessively vulgar and unlady-like. Never turn your head to look at those seated behind you, or near you. If you speak to your companion while the curtain is up, lower your voice, that you may not disturb others interested in the conversation on the stage. THE OPERA--Here you should wear full dress, an opera cloak, and either a head-dress, or dressy bonnet of some thin material. Your gloves must be of kid, white, or some very light tint to suit your dress. Many dress for the opera as they would for the theatre; but the beauty of the house is much enhanced by each lady contributing her full dress toilette to the general effect. If you go to the dressing-room, leave your hood and shawl in the care of the woman in waiting, whom you must fee when she returns them to you. If you do not wish to go to the dressing-room, allow your escort to take off your shawl or cloak, and throw it over the back of the seat. As your opera cloak must be light enough to keep on all the evening, though you may throw it open, you must wear over it a heavier cloak or a shawl. Throw this off in the lobby, just before you enter your box. Your gloves you must keep on all the evening.