Wash and scrub with a brush two quarts clams, changing water several times. Put in kettle with one-half cup cold water, cover tightly, and steam until shells are well opened. Remove clams from shells and strain liquor through double thickness cheesecloth. To one and two-thirds cups clam liquor add two and one-half cups White Stock III, highly seasoned. Cool, and freeze to a mush. Serve in place of a soup in frappé glasses, and garnish with whipped cream.