Wash six fine, medium-sized potatoes, peel and cut them into small dice-shaped pieces, wash again in fresh water, take them up with a skimmer ; place them in a stewpan large enough to hold three quarts. Immediately add two quarts of cold water (not placing the pan on the fire until so mentioned). Peel one medium-sized, sound onion, chop it up very fine, and place it on a plate. Take a quarter of a bunch of well-washed parsley greens (suppressing the stalks), place it with the onions ; wash well two branches of soup celery, chop it up very fine, place it with the parsley and onions, and add all these in the stewpan. Place the pan on a brisk fire. Season with a light pinch of salt, adding at the same time a light tablespoonful of good butter. Let all cook until the pototoes are nearly done; eighteen minutes will be sufficient. Cut out from a piece of fresh pork, crosswise, one slice a third of an inch thick, then cut it in pieces a third of an inch square, fry, and reduce it in a pan on the hot stove for four minutes. Add it to the broth, add also three-quarters of a teaspoonful of branch dry thyme. Lightly scald four fine, medium-sized tomatoes, peel and cut them into small pieces and add them to the preparation. Open and place in a bowl twenty-four medium-sized, fine, fresh clams ; pour into another bowl half of their juice. Place the clams on a wooden board, cut each one into four equal pieces, and immediately plunge them into the pan with the rest ; gently mix, so as to prevent burning at the bottom while boiling, for two minutes. Range the pan on the corner of the stove to keep warm. Season with a saltspoonful of black pepper, one tablespoonful of Worcestershire sauce, gently stir the whole with a wooden spoon ; break in two pilot crackers in small pieces, stir a little again. Leave two minutes longer in the same position, but under no circumstances allow to boil. Pour it into a hot soup-tureen, and serve.