Preheat oven to 400 degrees. In a Dutch oven, combine the blackberries, 1 cup sugar, 1/4 ts salt and lemon extract. Bring to a boil. Reduce heat and simmer for 5 minutes. In a mixing bowl, combine the flour, baking powder, nutmeg, 1 tbsp. sugar, and remaining salt. Add the milk. Stir just until mixed. Dough will be very thick. Drop by tablespoonfuls into six mounds onto the hot blackberry mixture. Bake at 400 degrees for 35 to 45 minutes.
Variation: Substitute a 9-inch piecrust for the dumpling mixture.