Ruth Fox Hume, a writer and teacher and the wife of Washington Post music editor Paul Hume, died Saturday of cancer at Sibley Hospital. She was 57.

Born in New York City, Mrs. Hume came to Washington in 1933. She attended Holy Cross Academy and graduated summa cum laude from the College of New Rochelle in 1943. After working for a time as a copywriter for Woodward and Lothrop, Mrs. Hume began a teaching career at Dunbarton College where she taught chemistry, her college major. She later taught Latin at Catholic Unversity and, after her marriage, taught at the Washington School of the Ballet and the School of the Holy Child in Potomac, including English, history, and mathematics among her subjects.

Her first books, published by Dodd, Mead & Co., were myteries: "Deadline," "Bitter Ending," and "Symphony in Two Time." She then turned to the field of medical history, having spent nearly a year as a student at the Long Island College of Medicine before deciding that a career in medicine was not her true goal. Her next books were "Milestones of Medicine" (which was also printed in German, French, Spanish, and Japanese), "Great Men of Medicine," "Great Women of Medicine," and a biography of Florence Nightingale, all published by Random House.

In addition to regular magazine articles, published in the Inter-Racial Review and American Heritage, Mrs. Hume collaborated with her husband on biographies of Ignace Paderewski and John McCormack.

At the time of her death she had nearly finished her first novel in many years, a medical gothic mystery about a young woman doctor.

In appreciation of a group of Montgomery County doctors who were of inestimable help to her in a seven-year battle with cancer, Mrs. Hume wrote a short book in 1976 entitled "Medicine in Maryland," the proceeds of which have gone to the AMA Education and Research Foundation. She was a member of the Children's Book Guild and a member of the board of directors of Gonzaga College High School for eight years.

Mrs. Hume is survived by her husband and four children, Paul Russell of Washington, Michael of New York City, and Ann and Peter, both of Boston.

The family suggests that expressions of sympathy be in the form of contributions to the Gonzaga College High School Science Laboratories or to the AMA Education and Research Foundation.