Scrub clams well and rinse in cool water. Slice linguica and crumble. Place lingucia, tomatoes, onion, scallions, parsley, garlic, wine and ¾ cup of water into a large kettle. Place clams on top, cover and bring to a boil. Boil until the clams have opened completely. To serve, divide clams and sauce equally into 4 large soup plates. Serve with extra broth on the side and plenty of crusty Portuguese bread.