Samuel Gardner (Cotton) Coale, 66, a liquor and soft drink dealer in the Washington area for many years and a lifelong resident of Prince George's County, died of cardiac arrest Monday at Doctors Hospital in Lanham.

From 1938 until his retirement about three years ago, Mr. Coale was a partner in the firm of Hall and Coale, which had part of the liquor and soft drink concession at Bowie Racecourse. The firms, one of whose founders was Mr. Coale's father, also had part of the concession at the old Marlboro race track.

Mr. Coale had operated a liquor store in District Heights for the past 28 years.

For about five years in the 1950s, he was a Maryland state racing inspector. Such inspectors are responsible for the testing of racehorses for drugs. Mr. coale had been active in Republican politics in Prince George's County at one time.

Mr. Coale was born in Croom and grew up there and elsewhere in Prince George's County. He attended Strayer's Business College in Washington before joining Hall and Coale. Mr. Coale also was an enthusiastic farmer and gardener. For many years he raised tobacco on family land in Prince George's County. He had owned a small farm in Chaneyville for the past nine years.

Survivors incude his wife, Carrol, whom he married 47 years ago, of the home in Forestville; two daughters, Linda C. Western, of Temple Hills, and Jacqueline C. Smith, of Chaneyvill; four sisters, Barbara Moore, of Croom, Christabel Hurley, of Salisbury, Md., Charlotte Fontana, Upper Marlboro, and Jacqueline Greer, of St. Mary's County, and five grandchildren.