I08 HARVARD LAW REVIEW, In order to determine the proper answer to this question, it is necessary to consider the legal position of the parties to an execu- tory contract for the sale of personal property. Only personal obligations are created. The purchaser acquires no jus in rem, and the owner '* may, in defiance of his contract, sell to some third person and give him a perfectly good title, even if that third person had notice of the prior contract."^ It is necessary also **to point to a distinction, which, although a fine one, seems nevertheless to be a clear one, between contracts which are intended to operate as sales at some future time, and contracts which are intended to operate merely as promises to sell. It is the difference which exists between an agreement that the property shall pass on the happening of some future event without anything further to be done by either party in that behalf, and an agreement by which one party promises that on the happening of some event he will then transfer the property." ^ It is comparable to the difference be- promissory note because, as the court said, if the consideration perished before matur- ity, the maker would not be liable. The note was therefore not an absolute promise. A similar decision, based on the same reason, was made in Sloan v. McCarty, 134 Mass. 245. On the other hand, in Chicago, &c. Co. v. Merchants' Bank, 136 U. S. 268, such a note was held negotiable, and the argument of the Massachusetts cases was expressly denied, the court saying that the maker would be bound to pay the note even though the property for which it was given perished by accident before maturity of the note. Other decisions holding such notes negotiable, and necessarily involving, though not stating, the same conclusion, are Howard v. Simpkins, 69 Ga. 'j']'^ Mott v. Havana Bank, 22 Hun, 354 ; Heard v. Dubuque Bank, 8 Neb. 10 ; Newton Wagon Co. v. Diers, 10 Neb. 284 ; W. W^. Kimball Co. v. Mellon, 80 Wis. 133. It was held that such notes were not negotiable, but for reasons not affecting the question under consideration, in Killam v. Schoeps, 26 Kan. 310; South Bend Works v. Paddock, y] Kan. 510; Wright V. Traver, 73 Mich. 493 ; Third Bank v. Armstrong, 25 Minn. 530; Minneapolis Har- vester Works V. Hally, 27 Minn. 495 ; Stevens v. Johnson, 28 Minn. 172 ; Deering v. Thom, 29 Minn. 120; (but see Aultman v. Olson, 43 Minn. 409); Dominion Bank v. Wiggins, 21 Ont. App. 275. 1 Blackburn, Contract of Sale, 2d ed., p. 244. 2 Ibid.^ p. 247. The passage continues : " In the latter case the property does not pass until he does not sell the thing, although the event may have happened, and such a contract at law creates merely a personal obligation to pass the property, and that at law will not create any real right ox pis in rem. In equity, however, the vendee is in a better position, and such a contract would, when the event had happened, give him a good equitable title to the goods against all persons, excepting.any one who, in the mean time and bona fide, may have had the property transferred to him." The leading case illustrating the rule in equity is Holroyd v. Marshall, 10 H. L. C. 191. See also Collyer V. Isaacs, 19 Ch. D. 342 ; In re Clarke, 36 Ch. D. 348 ; Morris v. Delobbel-Flipo, [1892] 2 Ch. 352, and other cases therein referred to. In the United States this doctrine of equity is generally followed (Am. & Eng. Cyc. of Law, vol. iii. pp. 183, 184, vol. xxi. p. 472) but not universally. Blanchard v. Cooke, 144 Mass. 207. It will be observed that the question can only arise in equity when the contract of sale is one of which equity