A man who has the illness called dropsy (a disease of excessive water retention) can be cured if the Indian stone is tied to him. The stone will absorb the man's impurities, and in so doing comes to weigh as much as the man. If the stone is then placed in the sun for three hours, the impure water will drain out of it and it can be re-used.

Physiologus says: The stone is our Lord Jesus Christ. Because we were dropsical, having the waters of the devil in our hearts, the stone of the Savior came down and was bound and his love surrounded our hearts. Rising from the dead, however, he took away from our soul every intelligible infirmity. "And he himself bore our infirmities" [Matthew 8:12]. - [Curley translation]