Indian Contract Act, 1872
157. Effect of mixture, without bailor's consent, when the goods cannot be separated
If the bailee, without the consent of the bailor, mixes the foods of the bailor with his own goods in such a manner that it is impossible to separate the goods bailed from the other goods, and deliver them back, the bailor is entitled to be compensated by the bailee for the loss of the goods.
A bails a barrel of Cape flour worth Rs. 45 to B. B, without A's consent, mixes the flour with country flour of his own, worth Rs. 25 a barrel. B must compensate A for the loss of his flour.