Mix all ingredients in a 3 quart saucepan. Bring slowly to a boil, stirring constantly. Bring to full rolling boil for about 8 minutes, stirring occasionally ( a small amount dropped into cold water should form a soft ball at 235ºF. ) Remove pan from heat; cool slightly, beat mixture until thick. Pour into greased shallow pan. When nearly set, mark into squares. Separate pieces, when set, and leave to harden on plate