English Toffee - Great Grandma Evelyn Rollins

4 cups brown sugar
1 can sweetened condensed milk
1/2  pound butter
nuts

Mix ingredients together and cook in heavy pan, stirring all the while until it forms a firm ball when added to cold water. Pour into buttered roll pan that has nuts on the bottom. Cool then cut into rectangles.  Roll individually in waxed paper or plastic wrap.