Peanut Brittle

Grease well one baking sheet. Mix first 4 ingredients in heavy 2 quart saucepan. Cook over medium heat, stirring constantly until sugar is dissolved and mixture comes to boil. Continue cooking without stirring until temperature reaches 280 degrees, or until small amount of mixture separates into hard but not brittle threads in cold water. Gradually stir in peanuts so mixture continues to boil. Cook, stirring frequently, until temperature reaches 300 degrees or until small amount of mixture separates into hard and  brittle threads in cold water. Remove from heat. Add baking soda; blend quickly and thoroughly. Immediately turn onto prepared baking sheet. Spread mixture evenly to edges with greased metal spatula. Cool. Break into pieces.