Preheat oven to 375 degrees F.
Wash and thoroughly dry the potatoes. Place in a baking pan just large enough to hold the potatoes in a single layer. Pour 1 1/2 cups salt over the potatoes and bake until the potatoes are tender in the middle, about 1 hour 15 minutes (depending on size of potatoes). Serve either in the salt for pretty presentation, or removed from salt and in a serving dish. Serve with butter.