The Devil's Pool by George Sand

Germain came soon to the spot where he had passed the night on the border of the pool. The fire was smoking still. An old woman was gathering the remnants of the wood little Marie had piled there. Germain stopped to question her. She was deaf and mistook his inquiries.

"Yes, my son," said she, "this is the Devil's Pool. It is an evil spot, and you must not approach it without throwing in three stones with your left hand, while you cross yourself with the right. That drives away the spirits. Otherwise trouble comes to those who go around it."