Grace Henrietta Roper Bohn, 84, a specialist in economics and international relations for the old U.S. Tariff Commission and the daughter of the late Daniel C. Roper, who was secretary of commerce during two of Franklin D. Roosevelt's administrations, died Tuesday at the Quincy Methodist Home in Quincy, Pa., after a heart attack.

Mrs. Bohn worked for the Tariff Commission, now the U.S. International Trade Commission, during the 1920s and 1930s. One of few women tariff experts in the country at that time, she handled tariff and trade relations for Canada and Britain in the commission's international relations division.

A native of Washington, Mrs. Bohn was a cofounder in 1934 of the now-defunct Washington Town Hall Meetings, popular forums during the 1930s and 1940s that featured Sunday night lectures at the Shoreham Hotel here by nationally and internationally prominent persons.

Mrs. Bohn earned a bachelor's degree from Vassar College in 1917 and went on the earn a master's degree in economics from the University of Vermont, a master's degree in international relations from the University of Southern California and a master's degree in economics and international relations from American University.

In 1935, she married Dr. Frank Bohn, a writer and lecturer in international relations, whom she met while at the University of Southern California. He died in 1975.

Mrs. Bohn moved from Washington to Blue Ridge Summit, Pa., in 1955. She had lived at the Quincy Methodist Home in Pennsylvania in recent years.

Survivors include a brother, retired Army Maj. Gen. Harry McK. Roper of Washington.