Sydney A. Smith of Boca Grande, Florida, formerly of this city, member of a family long identified with New York society, died yesterday in St. Claire's Hospital, of a heart attack after an illness of ten days. His age was 54. He was born in Westbury, L.I., a son of the late Mr. and Mrs. Sydney J. Smith. His mother, the former Fannie B. Tailer, was Mrs. Tailer Carpenter at her death a year ago. ... In 1930, Mr. Smith wed Florence Rice, daughter of Grantland Rice, the sports writer. She obtained a divorce a year later. His second marriage in 1935 to Lillian Bond, film actress, also ended in divorce.