Rule 5. (1) Where there is a contract for the sale of unascertained or future goods by description, and goods of that description and in a deliverable state are unconditionally appropriated to the contract, either by the seller with the assent of the buyer or by the buyer with the assent of the seller, the property in the goods then passes to the buyer; and the assent may be express or implied, and may be given either before or after the appropriation is made.
(2) Where, in pursuance of the contract, the seller delivers the goods to the buyer or to a carrier or other bailee or custodier (whether named by the buyer or not) for the purpose of transmission to the buyer, and does not reserve the right of disposal, he is to be taken to have unconditionally appropriated the goods to the contract.
(3) Where there is a contract for the sale of a specified quantity of unascertained goods in a deliverable state forming part of a bulk which is identified either in the contract or by subsequent agreement between the parties and the bulk is reduced to (or to less than) that quantity, then, if the buyer under that contract is the only buyer to whom goods are then due out of the bulk -
(a) the remaining goods are to be taken as appropriated to that contract at the time when the bulk is so reduced; and
(b) the property in those goods then passes to that buyer.
(4) Paragraph (3) above applies also (with the necessary modifications) where a bulk is reduced to (or to less than) the aggregate of the quantities due to a single buyer under separate contracts relating to that bulk and he is the only buyer to whom goods are then due out of that bulk.