I recently bought a copy of ''The New Book of American Etiquette (circa 1924 )'' for 10 cents at a garage sale. As I leafed through the dog-eared pages, I saw a yellowed and nearly crumbling sales slip. The book's previous owner, Mrs. H. H. Crossman, had bought it on Dec. 12, 1933, for $1 at Hutchinson's Book Store, New Bedford, Mass.
I wondered about Mrs. Crossman. I imagined her an elegantly dressed young woman for whom good manners were as important in her life as the air she breathed.
She probably mingled comfortably with all people and in all environments, so good was her deportment. She instructed the household staff as politely as she discussed current affairs with the guests who attended her dinner parties.
Her impeccable table manners freed her from worry at the formal dinners she gave. Hands quietly folded in her lap and, with just a nod of her head, she would signal the butler to serve those meals. She knew exactly which piece of silver to use with each course (always work from the outside, in) and she used her knife as infrequently as possible; when she did, it was only for cutting food.
As hostess of the dance after dinner, Mrs. Crossman knew simplicity was the keynote of the day. Important that the function be one where her friends and acquaintances could gather in jollity, she avoided lavishness and display in her ballroom decorations. She knew that a huge fern in some unexpected corner, or a great mass of flowers in some spot where it wouldn't interfere with the dancing, was considered tasteful.
On less formal occasions, she knew that the radio dance was an acceptable form of entertainment. Because she'd read it in ''The New Book of American Etiquette,'' Mrs. Crossman knew that ''the hostess who has a very good radio receiving set may call a few friends or acquaintances on the telephone and say, 'The Gipsy String Band is broadcasting tomorrow at eight. Don't you want to come over and dance a little?' ''
She knew it was her responsibility to see that her guests mingled, so she took great care with her introductions. To get conversations started, she relied on her knowledge of the curious marriage customs in Albania, or the picturesque peasantry of Russia.
Assuming Mrs. Crossman is today in her 70s, I wonder what she thinks of the events in her lifetime. If she studied that etiquette book carefully, she probably saw the paragraph that said, ''It would be a simple matter to fill this page with generalities and tell you what you must do and what you must not do. But such advice would be quite useless, for what is correct and in good form today is often impossible tomorrow.''
A regular monthly column in the Book Review.