In a large pot, blend together sugar, cornstarch, cinnamon, nutmeg and salt. Stir in the water and lemon juice with a wire whisk. Cook and stir until bubbly and thick; remove from heat.
While the filling was cooking, slice the apples and added them into a solution of 3 tablespoons of lemon juice to 1 quart of water to avoid discoloration. Drain the fruit well before packing in jars. Pack apples into clean, hot canning jars leaving an inch from the top of the jar.
Fill with the hot syrup, leaving 1/2 inch space from the top of the jar. Remove air bubbles by running a knife around the insides of each jar. Close the jars with sterile lids and rims. Process in a boiling water bath for 20 -30 minutes.
Use a jar tongs to remove the jars from water. Place the jars on a dish towel to dry and allow the jars to cool for several hours. Check the seals to make certain the lids are sealed properly.