Ruth Gold Cohn, 91, formerly of Elkins Park, an activist for Jewish charities, died of heart failure July 25 at Watermark at Logan Square in Philadelphia.

For more than 40 years, Mrs. Cohn and her husband, Sidney, were volunteers and supporters of agencies affiliated with the Jewish Federation of Greater Philadelphia. They chaired the Family Affair benefit for Jewish Family and Children's Services of Greater Philadelphia for several years, and in the 1990s they were ad book cochairs for the annual Rainbow Ball to benefit the Philadelphia Geriatric Center, now the Abramson Center for Jewish Life.

When the couple were honored at the Rainbow Ball in 1999, Bennett Goldstein, who was the center's board chairman, said: "Ruth and Sidney are truly caring and always giving, as they fulfill the holiest of our obligations to watch over our elderly."

Mrs. Cohn's interest in the aging was a family tradition. In 1952 her mother, Anna Gold, joined the first board of directors of what was the Home for the Jewish Aged in Philadelphia; Gold had become a supporter of the home to honor her recently deceased husband, Joseph, who thought it was important to help the aged because they were often "just forgotten."

Mrs. Cohn followed her mother's footsteps and served on Philadelphia Geriatric Center committees and as vice chairwoman of the center's board. From 1979 to 1982, she was president of the Women's Council of the Women's Division of the Jewish Federation of Greater Philadelphia.

"Ruth had the vision and the people skills to encourage a strategic planning process which laid the groundwork for the structure and philosophy we use today," said Bari-Joy Epstein, director of women's philanthropy for the federation. "Ruth participated in fund-raising activities including many of our phone-athons. She was a master at closing donors' gifts, usually for an increase."

Mrs. Cohn's son, physician John Cohn, said: "People couldn't say no to her. She was charming and persuasive. She would convince you that you were giving to a good cause."

Mrs. Cohn grew up in Olney and graduated from Philadelphia High School for Girls. She earned a bachelor's degree in education from the University of Pennsylvania. After her children were raised, she earned a master's degree in counseling from Penn.

She and her husband met at a USO social in Philadelphia during World War II and married in 1945.

In addition to her husband and son, Mrs. Cohn is survived by another son, Rabbi Moshe Cohn; 11 grandchildren; and 13 great-grandchildren.

A funeral was held last Sunday at Goldsteins' Rosenberg's Raphael-Sacks Memorial Chapel in Philadelphia. Burial was in Roosevelt Memorial Park, Trevose.

Memorial donations may be made to the Abramson Center for Jewish Life, 1425 Horsham Rd., North Wales, Pa. 19454.