1 Ibid.; Leslie v. Guthrie, 1 Bing. N. C. 697.

"The same doctrine was maintained by Mr. Vice-Chancellor Shadwell, in Douglas v. Russell (4 Sim. 524), and his decree was afterwards affirmed by the Lord Chancellor (1 Myl. & K. 488), upon appeal, as to an assignment of freight earned and to be earned on an outward and homeward voyage, then about to be undertaken. And it was acted upon and supported in a like assignment of freight to be earned on a particular voyage in the case of Leslie v. Guthrie (1 Bing. N. C. 697, 708, 709), where the whole subject was argued at large, in a suit of the assignees under a bankruptcy.

"But the latest case, and certainly one of the most important and satisfactory in its reasoning, as well as its conclusion, is that of Langton v. Hor-ton (1 Hare, 549), before Mr. Vice-Chancellor Wigram. There a deed of assignment by way of mortgage was made of a whale-ship, and her tackle and appurtenances, and all oil and head-matter and other cargo, which might be caught and brought home in the ship on and from her then present voyage; and the question arose between an execution creditor of the assignor, and the assignee, whether the assignment was good as to the future cargo obtained in the voyage after the assignment. The learned Vice-Chancellor decided that it was. Upon that occasion he said: ' Is it true, then, that a subject to be acquired after the date of a contract cannot, in equity, be claimed by a purchaser for value under that contract ? It is impossible to doubt, for some purposes at least, that, by contract, an interest in a thing not in existence at the time of the contract may, in equity, become the property of a purchaser for value. The course to be taken by such purchaser to perfect his title, I do not now advert to; but cases recognizing the general proposition are of common occurrence. A tenant, for example, contracts that particular things, which shall be on the property when the term of his occupation expires, shall be the property of the lessor at a certain price, or at a price to be determined in a certain manner. This, in fact, is a contract to sell property not then belonging to the vendor, and a court of equity will enforce such contracts, where they are founded on valuable consideration, and justice requires that the contract should be specifically performed. The same doctrine is applied in important cases of contracts relating to mines, where the lessee has agreed to leave engines and machinery not annexed to the freehold, which shall be on the property at the expiration of the lease, to be paid for at a valuation. The contract applies, in terms, to implements which shall be there at the time specified; and here neither whaling voyage.1 Nor is it necessary that the fund assigned be of a definite or ascertained amount. But it has been laid down that where an equitable interest is assigned, in order to give the assignee a locus standi in a court of equity, the party assigning that right must have some substantial possession, some capability of personal enjoyment, and not a mere naked right to overset a legal instrument.2

§ 470. Again, in equity, a valuable consideration is not now held to be necessary to support an assignment, provided the instrument of assignment be complete in form, - on the ground that a trust is created thereby, which is to be distinguished from a merely voluntary contract.3 But a mere agreeconstruction nor decision has confined it to those articles which were on the property at the time the lease was granted.

" 'But it is not necessary that I should refer to such cases as these, for Lord Eldon, in the case of the ship Warre (8 Price, 269, n.), and in Curtis v. Auber (1 J. & W. 526), has decided all that is necessary to dispose of the present argument. Admitting that those cases are not specifically and in terms like the principal case, they are not of the less authority for the present purpose; for they remove the difficulty which has been raised in argument, and decide that non-existing property may be the subject of valid assignment.

" 'I will suppose the case of the owner of a ship, which is going out in ballast, proposing to borrow of another party a sum of 5000 to pay the crew and furnish an outfit, and agreeing that, in consideration of the loan, the homeward cargo should be consigned to the party advancing the money. It cannot reasonably be denied, in the face of the authorities I have just referred to, that a court of equity, upon a contract so framed, would hold that the party advancing the money was, as against the owner, entitled to claim the homeward cargo. And if a party may contract for the consign-ment of a homeward cargo, I cannot see why he may not contract with the owner of a ship engaged in the South Sea fisheries, that the fruit of the voyage, the whales taken, or the oil obtained, shall be his security for the amount of his advances. I cannot, without going in opposition to many authorities which have been cited, throw any doubt upon the point that Birnie, the contracting party, would be bound by the assignment to the plaintiffs.'

" Now, it seems to me that this reasoning is exceedingly cogent and striking; and it stands upon grounds entirely satisfactory and conclusive upon the whole subject."

1 Mitchell v. Winslow, 2 Story, 630; Langton v. Horton, 1 Hare, 549.

2 Per Lord Abinger in Prosser v. Edmonds, 1 Younge & Coll. 496; 2. Story, Eq. Jur. § 1040 g.

3 Kekewich v. Manning, 1 De G. M. & G. 176; 12 Eng. Law & Eq. 120; vol. I. 27 ment, or executory instrument of conveyance, would not be valid as an assignment, without consideration; for a court of equity will not interpose to assist mere volunteers.1

§ 471. At law, the doctrines are by no means so liberal in cases of assignment, although the differences are in most respects merely formal. The assent of the debtor is absolutely required at law in order to enable the assignee to bring an action in his own name against him;2 and a mere order on him to pay over to a third person the funds of the drawer in his hands, will be insufficient until it is accepted.3 There are, however, certain exceptions which obtain in favor of negotiable instruments, and which are created by the policy of the law, to answer the demands of public convenience.4 If, therefore, a contract be negotiable and payable to order, it may be assigned by mere indorsement; and if it be payable to bearer, a simple delivery constitutes a sufficient assignment.5 But the mere