Place milk, sugar and cream of tartar in a heavy saucepan. Stir to dissolve.
Cook over low heat for about 1 hour or until mixture begins to thicken. Stir occasionally
and first and constantly later on. When mixture thickens, check by caramel method
(dropping a drop of the mixture into a cup of cold water until a soft ball forms)
or use a candy thermometer to 232 degrees F.
Remove from heat. Add chopped pecans.
Pour into a wax paper-lined square cake pan and let it cool.
Cut into squares.
Makes 2 dozen small squares.
Variation: Omit chopped pecans. Pour mixture by spoonsful onto wax paper, and
top each piece of candy with a pecan half.