Butter sides of heavy saucepan. Combine sugar, milk, cream, syrup and salt. Stir over medium heat until boiling. Cook to soft ball stage. Remove from heat and cool to lukewarm. Add butter and vanilla. Beat until mixture is stiff, about 5 minutes. Quickly stir in the cherries. Spread into a buttered 9 x 5 x 3-inch pan. Cut into pieces when cool. Makes about 2 1/2 dozen pieces.