Thompson v Davenport
A formative but ultimately uninfluential case on the principle of undisclosed agency in which Lord Tenterden devised a rule (that an undisclosed principal is not liable to the vendor if the principal has paid or settled accounts with the agent) which Parke B roundly dissed in the subsequent case of Heald v Kenworthy. Discussed at some length in Poretta v Superior Dowel Company (transcript here.