Thus when a part only of the goods have been delivered, upon a contract like the present, and one party refuses to complete it by delivering or accepting the remainder, the other party may then elect to treat such refusal as a repudiation or rescission of the unfulfilled part of the contract. If the seller refuses to deliver, the purchaser may recover back any excess of purchase money that has been paid by him, beyond the price of what has been delivered * * *. But if the breach of the contract on the part of the seller is only in the quality, the other party cannot convert that into a rescission, but must, if he intends to rescind at all, rescind in toto." ( Mansfield v. Trigg, 113 Mass. 350, 353.) This is a very good statement of the common law which obtains in this jurisdiction.