Will Mercer Cook, 84, a former ambassador to Niger and Senegal and a retired chairman of the romance language department at Howard University, died of pneumonia Oct. 4 at the Washington Hospital Center. He lived in Washington.

Dr. Cook was named ambassador to Niger in 1962, and he served there three years before he was named ambassador to Senegal, a post he held for two years. He retired in 1970 as chairman of the romance language department at Howard, where he spent most of his academic career.

He was a native of Washington and a graduate of Dunbar High School. He graduated from Amherst College where he was a member of Phi Beta Kappa. He did graduate study in French language and literature in France and received a doctorate in French from Brown University.

Dr. Cook began his teaching career at Howard. He also taught during the 1930s at Atlanta University and in Haiti. He was on the Howard faculty during the 1940s and 1950s, and he took a leave of absence in when he was named an ambassador. After leaving his diplomatic posts, Dr. Cook taught briefly at Harvard University, then returned to Howard where he taught until he retired.

He had translated the works of several West Indian writers from French into English, and he had also produced English translations of the works of Leopold Senghor, a former president of Senegal and a noted French author.

He was author of the book "Militant Black Writers in Africa and the United States."

His wife, Vashti Smith Cook, died in 1969. Survivors include two sons, Mercer Cook Jr. of Chicago and Jacques Cook of Washington, and five grandchildren.

JOHN FIELDING BURNS, 77, a retired patent examiner with the U.S. Patent Office who was active in church and cultural groups in Northern Virginia, died of a heart ailment Oct. 3 at Arlington Hospital. He lived in Arlington.

Mr. Burns was a charter member and trustee of the Arlington Historical Society and served as its president in 1965. He was an authority on early Arlington County and railroads. He also had served as area chapter president of the National Association of Watch and Clock Collectors.

He was a member of Rock Spring Congregational Church in Arlington where he had been a deacon and sang in the choir. He also had chaired the church property planning and maintenance board.

Mr. Burns was a native of Washington and a graduate of McKinley High School. He graduated from George Washington University in 1932 with a degree in electrical engineering. He served with the Army Air Forces during World War II and retired from the Air Force reserves as a captain in 1970.

He spent 30 years with the government before retiring in 1965. He began his career with the U.S. Coast and Geodetic Survey, but after a short time transferred to the Patent Office.

His wife, the former Louisa Saegmuller, died in 1985. Survivors include two sons, Dr. Allan, of Parkesburg, Pa., and John Fitzhugh Burns of Silver Spring; a daughter, Barbara Page Gomez of Santo Domingo, Dominican Republic; a brother, Walter W. Jr., of Arlington; 10 grandchildren, and two great-grandchildren.

SAM R. FOGG, 70, who had been a reporter and editor in Ohio, New York and Washington with the old International News Service, United Press International, and the Jack Anderson syndicated column, for more than 40 years before retiring in 1983, died of cancer Oct. 5 at his home in Washington.

Mr. Fogg, who moved here in 1947, was a native of Akron, Ohio, and attended Kent State University. Before World War II, he was a reporter for newspapers in Ohio. He joined INS in Cleveland in 1943. He worked for the Office of War Information in Europe in 1944 and 1945.

He returned to INS after the war. He covered the United Nations in New York before transferring here. He joined UPI when it was formed by the merger of United Press and INS in 1957.

Over the years, he wrote about Congress, the White House, the Supreme Court and sports. He was lead writer for UPI coverage of the bicentennial and was also a copy editor. After retiring from UPI in 1978, he joined Jack Anderson's staff, where he worked until retiring a second time.

Mr. Fogg had served on the board of governors of the National Press Club.

Survivors include his wife, Betty, of Washington; a son, Louis, of Chicago; a daughter, Susan Braaten of Falls Church, and a grandson.

LOUISE F. FREEMAN, 76, a retired government lawyer who was active in Jewish organizations, died of cancer Oct. 3 at George Washington University Hospital. She lived in Washington.

Mrs. Freeman was born in New York City and moved here in 1917. She was a graduate of George Washington University, where she also received a law degree and was a member of the Order of the Coif.

She lived in New York for 11 years before returning to Washington in 1943. During her years in New York, she became deputy director of the state rationing board and a regional rationing executive with old Office of Price Administration in New York City.

She continued to work for OPA after returning here. She also worked for the old Federal Security Agency before finally joining the Labor Department. She retired from the government in 1973 as the Labor Department's chief counsel for unemployment insurance. She also had been a consultant to Senate and House committees dealing with banking.

Mrs. Freeman had been a member of the Sisterhood of Temple Sinai in Washington, the B'nai B'rith, the Naitonal Counsel of Jewish Women, and Hadassah. She also was a member of the League of Women Voters.

Survivors include her husband, Leo, of Washington; a daughter, Jane F. Oderberg of Fort Worth; her mother, Vera R. Feinstein of Washington, and three grandchildren.

REBECCA D. VAUGHAN, 79, a retired employe of the security division of the Central Intelligence Agency, died Oct. 1 at Sibley Memorial Hospital. She had kidney failure.

Mrs. Vaughan was a native and resident of Washington. She began her career with the federal government in the mid-1930s. Before joining the CIA, she worked for a federal housing agency, the old Office of Strategic Services, and the old War Department.

She joined the CIA as a pass control officer in its inspection and security division in 1947. She retired from the government in 1968.

Mrs. Vaughan was a past member of St. Thomas Episcopal Church in Washington and the Junior League of Washington.

Her marriage to Benjamin Franklin Vaughan ended in divorce.

Survivors include a son, Jerauld, of Washington, and a brother, Thomas B. Davidson of Lancaster County, Va.

EVELYN HEYMAN, 83, an area resident since 1927 who was a native of New York City, died Oct. 3 at Sibley Memorial Hospital after a heart attack. She lived in Washington.

Her marriage to Jack Tendler ended in divorce.

Miss Heyman was preceded in death by two children. Her survivors include four grandchildren and two great-grandchildren.

LOLA R. BERG, 69, a lifelong area resident who was a member of the Woman's National Democratic Club, died Oct. 5 at George Washington University Hospital. She had cancer and pneumonia.

Mrs. Berg was a native and resident of Washington. She was a 1934 graduate of Central High School and attended George Washington University. From 1935 to 1940, she was a librarian with the Hecht Co. lending library. She worked for the Office of Price Administration during World War II.

Survivors include her husband, Eli, and a son, Gordon V., both of Washington, and a daughter, Shelley C. Berg of New York City.

CATHERINE M. BLASENA, 60, a nurse by training who was retired assistant director of nursing and health services with the American National Red Cross, died of congestive heart failure Oct. 2 at Alexandria Hospital. She lived in Alexandria.

Miss Blasena did volunteer work for the Red Cross in her native Minnesota, then joined the organization as a full-time employe in Minneapolis in 1952. She was a Red Cross nursing services administrator in Nebraska, Texas and Missouri before transferring here in 1976. She retired in January.

She was a graduate of the College of St. Catherine in Minnesota and received a master's degree in nursing from St. Mary's University in Texas. Miss Blasena was a member of St. Lawrence Catholic Church in Alexandria and the American Nurses Association. She also was a member of the Zonta Club, an Alexandria social organization.

She leaves no immediate survivors.

MARY C. BURNETT, 80, a retired mobile X-ray technician for the D.C. government and a former sales agent here for Southern Aid Insurance Co. who had served on the Virginia state board of the NAACP, died of cancer Oct. 2 at Washington Hospital Center.

Mrs. Burnett was born in King George County, Va., and attended Hampton University and Virginia State Normal School. She was a school teacher and she helped her husband operate a lumber and ice business in King George County before moving to Washington in 1950. In 1970, Mrs. Burnett retired and moved back to King George County.

She had served as King George County chapter president of the NAACP. She was registrar of the Mount Bethel Baptist Association, which includes Baptist Churches in Washington, Maryland and Virginia. She had been a delegate to the State Democratic Convention in Virginia and was a Democratic precinct coordinator.

Her husband, Wallace Burnett, died in 1966. Survivors include one daughter, Sylvia Williams of King George County, and two grandchildren.