Melt chocolate with milk and salt in double boiler. Stir constantly over boiling water until very thick. Gradually stir in water; keeping smooth, continue cooking, stirring often until mixture thickens. Remove from heat. Stir in vanilla. Pour into shell. Cool at room temperature half hour. Refrigerate at least 3 hours. Garnish with whipped cream just before serving.This is from a very old Eagle Brand cookbook. This is very rich and delicious!