In a small heavy saucepan combine sugar, corn syrup, butter, and a pinch of salt and cook over moderate heat, stirring, until sugar is dissolved. Boil syrup, without stirring, until it registers 280F. on a candy thermometer, about 5 minutes. Remove pan from heat and stir in cream, vanilla, and lemon juice, stirring until smooth. Sauce will thicken as it cools. Sauce keeps, covered and chilled, 3 weeks. Serve sauce warm or at room temperature over ice cream. Makes about 1 1/3 cups. Gourmet May 1995 Per serving: 1894 Calories (kcal); 90g Total Fat; (41% calories from fat); 3g Protein; 282g Carbohydrate; 287mg Cholesterol; 236mg Sodium Food Exchanges: 0 Grain(Starch); 0 Lean Meat; 0 Vegetable; 0 Fruit; 18 Fat; 18 1/2 Other Carbohydrates Converted by MM_Buster v2.0n.