To entitle a broker to a commission, where the exchange falls through because of a defect in the customer's title, the broker must have acted in good faith. Games v. Howard, 180 Mass.

569, 63 N. E. 122; Roche v. Smith, 176 Mass. 595, 58 N. E. 152;

Rockwell v. Newton, 44 Conn. 333.