Section 52. Definition of Unpaid Seller.—

1. The seller of goods is deemed to be an unpaid seller within the meaning of this act—

   1. When the whole of the price has not been paid or tendered.

   2. When a bill of exchange or other negotiable instrument has been received as conditional payment, and the condition on which it was received has been broken by reason of the dishonor of the instrument, the insolvency of the buyer, or otherwise.

2. In this part of this act the term "seller" includes an agent of the seller to whom the bill of lading has been indorsed, or a consignor or agent who has himself paid, or is directly responsible for, the price, or any other person who is in the position of a seller.