Tie the cinnamon, cloves and allspice loosely in a square of cheesecloth.
Combine vinegar with the bag of spices in a non-aluminum pan. Bring the vinegar to boiling, adjust the heat and simmer it, uncovered, for 15 minutes.
Add the tomatoes, bring the mixture to a boil, then adjust the heat and simmer the mixture, partly covered, until it resembles a puree, about 30 minutes.
Add the sugar, mustard seed, and Cayenne pepper. Pour the mixture into a bowl, cool and cover it, and let stand overnight at room temperature.
Meanwhile, combine the cucumbers, red and green peppers, celery, and onion in a ceramic or stainless-steel bowl. Sprinkle the turmeric and salt over the vegetables, then add the 8 cups of water. Stir the mixture, cover it, and refrigerate overnight.
Wash 7 half-pint jars. Keep hot until needed. Prepare lids as manufacturer directs.
Drain the liquid from the salted vegetables and replace it with enough fresh cold water to cover them; let the vegetables soak for 1 hour, then drain them in a colander, pressing lightly.
Return the vinegar/tomato mixture to pot and bring it to a boil over medium-high heat.
Add the drained vegetables, then return the relish to a full boil, stirring frequently, and cook it, uncovered, over high heat, for 5 minutes. Remove the relish from the heat.
Remove the spice bag from the relish; squeeze out all possible liquid from the bag into the pot, then discard the bag.
Ladle the hot relish into 1 hot jar at a time, leaving 1/2-inch head space. Wipe rim with a clean damp cloth. Attach lid. Fill and close remaining jars. Process jars in a boiling water canner for 10 minutes. Yields 7 half-pints.