For instance, in Marten v. Whale, Marten agreed to buy a plot of land from T in return for a car subject to the condition that his solicitor approved the title to the land. Before any transaction was done, Marten transferred the possession of his car to T who further sold it to Whale who was a bona fide buyer in good faith. It was held that Whale acquired good title as he was unaware that the seller did not have the authority to sell. In addition to sale, if the buyer makes any pledge or mortgage it should be equally effective. But it is mandatory that the real seller should have the authority to sell the goods. If he does not, the person taking possession from him will not get a good title.