The rules already stated as to the time at which the property passes from the seller to the buyer are merely guides to the intention of the parties in the absence of any clear expression of their intention, and those rules apply only, "unless a different intention appears" (Ont. s. 20; U.K. s. 18).
The general principle is that if the goods are specific or ascertained, or, in the case of unascertained goods, so soon as they become ascertained, the property passes to the buyer whenever the parties intend that it shall pass. It may of course be expressly provided by the contract that the property shall not pass until certain conditions are fulfilled. Moreover, when the seller appropriates goods to the contract, he may by the terms of the appropriation prevent the property from passing.
The Sale of Goods Act (Ont. s 21; U. K. s. 19) provides:
21. - (1) Where there is a contract for the sale of specific goods or where goods are subsequently appropriated to the contract, the seller may, by the terms of the contract or appropriation, reserve the right of disposal of the goods until certain conditions are fulfilled. In such case, notwithstanding the delivery of the goods to the buyer, or to a carrier or other bailee for the purpose of transmission to the buyer, the property in the goods does not pass to the buyer until the conditions imposed by the seller are fulfilled.
(2) Where goods are shipped, and by the bill of lading the goods are deliverable to the order of the seller or his agent, the seller is prima facie deemed to reserve the right of disposal.
(3) Where the seller of goods draws on the buyer for the price, and transmits the bill of exchange and bill of lading to the buyer together to secure acceptance or payment of the bill of exchange, the buyer is bound to return the bill of lading if he does not honour the bill of exchange, and if he unlawfully retains the bill of lading the property in the goods does not pass to him.
The term "right of disposal" is a translation of jus dis-yonend^. which is found in the cases with reference only to shipment under bills of lading. The provision contained in sub-s. 1 is not confined to cases of shipment, although the particular instances of reservation of the right of disposal given in sub-ss. 2 and 3 are so confined. Under sub-s. 3 it is not imperative that the bill of lading should pass through the hands of the seller's agent (Cahn v Pockett's Bristol Channel Steam Packet Co.,  1 Q. B. 643), though before the statute this was generally necessary.
Cf. 25 Halsbury, Laws of England, pp. 181 ff.; as to the reservation of the right of disposal, see also Benjamin, Sale, 5th ed., 1906, pp. 375 ff.
In the United States the words " right of possession or property" are substituted in the Uniform Sales Act (s. 20) for "right of disposal" in sub.-s. 1, the word "property" is substituted in sub.- s. 2, and the wording of the various sub-sections is somewhat altered. There is a provision added that Where the goods are shipped, and by the bill of lading the goods are deliverable to the order of the buyer or his agent, but possession of the bill of lading is retained by the seller or his agent, the seller thereby reserves a right to the possession of the goods as against the buyer.
If, upon an order for unascertained goods to be shipped f.o.b., the seller delivers to the designated common carrier goods which answer the order, and if, in the case of a bill of lading being taken, it is taken in the name of the buyer, the property passes forthwith to the buyer. If. however, the bill of lading is taken in the name of the seller, prima facie he retains the disposing power over and the property in the goods. If he endorses the bill of lading and forwards it to the buyer forthwith, the transaction is equivalent to the taking of the bill of lading in the name of the buyer, and the property passes at once but if the seller endorses the bill of lading in blank or to his agent and forwards it to his agent for delivery to the buyer upon payment for the goods, acceptance of a draft or performance of some other condition, then the goods remain in the control and are the property of the seller, at least until the condition is fulfilled or the buyer offers to fulfil it and demands the bill of lading.
Vipond v. Sisco, 1913, 29 O.L.R. 200, 14 D.L,R. 129, and cases cited; Graham v. Laird, 1909, 20 O.L.R. 11;
Turner v. Liverpool Docks, 1851, 6 Exch. 543, 4 R.C. 725;
Shepherd v. Harrison, 1871, L.R. 5 H.L. 116, L.R. 4 Q.B.
196, 23 R.C. 349; Ogg v. Shuter, 1875, 1 C.P.D. 47, 4 R.C. 746; Mirabita v. Imperial Ottoman Bank, 1878, 3 Ex. D. 164, at p. 172; Corby v. Williams, 1881, 7 Can. S.C.R. 470.
Although prima facie the taking of the bill of lading in the name of the seller prevents the property from passing, it may appear from the contract and the conduct of the parties that it is the intention of the parties that the property shall nevertheless pass.
The Parchim,  A.C. 157; cf. Standard Trust Co. v. Karst, 1914, 7 Sask. L.R. 290. 20 D.L.R. 10 The provisions of the Sale of Goods Act now in question (Ont. s. 21; U.K. s. 19) relate only to the passing of the property as between the seller and the buyer. If under sub.-s. 3 the buyer wrongfully retains the bill of lading, it may be that he can give a good title to a third party who takes the bill of lading in good faith and without notice. Cahn v. Pockett's Bristol Channel Steam Packet Co.,  1 Q.B. 643. In the United States the same principle is expressed in the following words which are added in the Uniform Sales Act (s. 20) to the sub-section corresponding with sub-s. 3:
If, however, the bill of lading provides that the goods are deliverable to the buyer or to the order of the buyer, or is endorsed in blank, or to the buyer by the consignee named therein, one who purchases in good faith, for value, the bill of lading or goods from the buyer will obtain the property in the goods, although the bill of exchange has not been honored, provided that such purchaser has received delivery of the bill of lading endorsed by the consignee named therein, or of the goods, without notice of the facts making the transfer wrongful. This question belongs to the subject of the next following chapter. See 44.