Drain blueberries, reserving syrup; add enough water to syrup to make 1 cup.
In blazer pan of chafing dish mix together the 1/3 cup sugar, cornstarch, and salt; gradually stir in syrup.
Cook and stir over direct heat till thickened and bubbly.
Stir in blueberries and lemon juice; return to boiling.
Dip biscuits in water, then roll in mixture of the 1/4 cup sugar and cinnamon.
Place biscuits in bubbly sauce (do not overlap); cover.
Cook 8 to 10 minutes or till done.