§ 796. Nor is it every usage that is admissible even to explain a contract. For if it be to do an illegal act, or if it violate the express requirements of a statute, or defeat the essential provisions of the contract, it cannot be given in evidence. Thus, a usage among banks in Massachusetts to regard a certain bank post-note, payable at a future day certain, as payable without grace, there being no express stipulation to that effect in the note itself, would not be admissible to explain the contract, because it is contrary to the Revised Statutes of Massachusetts, providing that on all promissory notes, payable at a future day certain, grace shall be allowed, unless there be words have various senses, some common, some qualified, and some technical, according to the subject-matter to which they are applied. But I apprehend, that it can never be proper to resort to any usage or custom to control or vary the positive stipulations in a written contract, and, a fortiori, not in order to contradict them. An express contract of the parties is always admissible to supersede, or vary, or control, a usage or custom; for the latter may always be waived at the will of the parties. But a written and express contract cannot be controlled, or varied, or contradicted by a usage or custom; for that would not only be to admit parol evidence to control, vary, or contradict written contracts; but it would be to allow mere presumptions and implications, properly arising in the absence of any positive expressions of intention, to control, vary, or contradict the most formal and deliberate written declarations of the parties.

" Now, what is the object of the present asserted usage or custom? It is to show, that, notwithstanding there is a written contract (the bill of lading), by which the owners have agreed to deliver the goods, shipped in good order and condition, at Boston, the danger of the seas only excepted; yet the owners are not to be held bound to deliver them in good order and condition, although the danger of the seas has not caused or occasioned their being in bad condition, but causes wholly foreign to such a peril. In short, the object is, to substitute for the express terms of the bill of lading an implied agreement on the part of the owners, that they shall not be bound to deliver the goods in good order or condition; but that they shall be liable only for damage done to the goods occasioned by their own neglect. It appears to me, that this is to supersede the positive agreement of the parties; and not to construe it. The exception must, therefore, be sustained." an express stipulation to the contrary.1 But where the usage is not immoral or illegal in itself, the mere fact that it is in contravention of the general rules of the common law will not render it inadmissible, provided it appear to be reasonable and convenient. Thus, where a certain cargo of corn was sold in bulk under a warranty, it was held that evidence was admissible to show a usage in the place where it was sold that the purchaser could keep as much of the corn as answered the warranty and decline taking the residue, - although the general rule of law required him, if he would rescind the sale, to restore the entire quantity.2 But a usage that warehouse receipts pass by delivery, without indorsement, has been held bad.3

1 Perkins v. Franklin Bank, 21 Pick. 483; Mechanics1 Bank v. Merchants1 Bank, 6 Met. 13. See also, to this point, Merchants1 Bank v. Woodruff, 6 Hill, 174.

2 Clark v. Baker, 11 Met. 189. Mr. Justice Dewey said: " In the present case, the usage found by the jury goes directly to establish a rule in contravention of the rules of the common law, in relation to rescinding a contract in a case of sale of an unsound article, accompanied by a warranty, or induced by false representations. The general rule of law requires the vendee, if he would rescind the sale for such cause, to restore the entire commodity purchased. The local usage proved is, that in a sale of corn under like circumstances, the party may keep so much of the commodity as answers the warranty or representation, and decline taking the residue; that is, he may rescind the contract in part, and, without returning the corn he has received, may recover back the money paid for so much of the article as does not answer the representation. This usage is certainly not an unreasonable one, and not to be rejected upon that ground. The nature of the commodity, the manner of exposing the article for sale, the price being fixed by the bushel, and the mode of delivery, all alike point out this as a reasonable and convenient usage. We understand the contract to have been an oral one. Such being the case, the admission of the evidence of the usage is not objectionable upon the ground of its being offered to control, vary, or contradict a contract in writing. Nor does the usage contradict any express oral contract made by the parties. Had it done either, it would have presented a very different question.

"Usages of this character are only admissible upon the hypothesis that the parties have contracted in reference to them. If the parties make express stipulations as to the terms of a sale, or the manner of performance of a contract, or state the conditions upon which it may be rescinded, such express stipulations must be taken as the terms of the contract, and they are not to be affected by any usage contrary to them.

3 Lehman v. Marshall, 47 Ala. 362 (1872).

§ 797. It must also appear that the usage is reasonable, or it will not be admitted in explanation of the contract. Thus, a usage among owners of vessels engaged in the whaling trade to accept all bills of their masters drawn on them for supplies furnished abroad, was held to be of .so unreasonable a character that the owners would not be governed thereby, even were the usage proved to exist.1

§ 798. Again, the usage must not be narrow, local, and confined; nor must it be the private opinion of a few; but it must be so uniform and notorious, and of such long standing, as to afford a presumption that the parties contemplated it as a part of their contract.2 Thus, the usage or custom of a particular port, in respect to a particular trade, is not a sufficient custom to limit the terms of a contract of insurance; but it must be some known or general custom in the trade, applicable to all ports of the State wherein it exists..1 So, also, proof that a particular mode of selling cotton in Mobile "was very common in the trade, but that a few factors in Mobile would not do so," was held not to be proof of a usage of trade.2