As the plaintiff below never had possession of the hay, which was on the defendant’s ground at the time of the alleged injury, he was bound, at least, to show a right of property. The proof of a purchase at auction, at a constable’s sale, without showing the au*536thorny under which the constable acted, was not enough. If the constable had no authority to sell the hay, the vendee had no title. The books have gone so far as to say, tlíat a vendee under a lawful judgment and execution, shall not lose his property, upon a reversal of the judgment by writ of error. This was so ruled in Manning's case, (8 Co. 96. b.) But no case admits a title in the purchaser, when the sheriff acted without authority. On this ground the judgment below must be reversed.