Make an infusion with violets and water by placing your blossoms in a glass jar and covering them with boiling water. Put a lid on the jar, and set aside for 24 hours. The infusion will turn a murky bluish green. Strain and discard the violets. Add the lemon juice to the violet infusion, and it transforms to a clear lavender pink. Stir in powdered pectin, and bring to a boil. Add 4 cups sugar, bring to a boil again, and boil vigorously for one minute. Skim if necessary. Pour into sterile jars and seal.