The principal question is in relation to the admissibility of evidence. The defendant had contracted in writing to sell to Hixon W. Field of New York, ten thousand tons of ice at $2.50 per ton. The plaintiffs wrote upon the back of a copy of this contract the words following:
"We, the undersigned, hereby agree to furnish to A. Eich, Jr. three thousand tons of ice (3000 tons) per the within contract.”
This writing is signed by the plaintiffs, and is dated May 15, 1876. This action is to recover for ice claimed to have been delivered in pursuance of this agreement. The form of the action is general indebitatus assumpsit upon an account annexed to the writ.
The exceptions state that the defendant’s counsel offered to prove by parol evidence that the defendant, under an understanding or agreement with the plaintiffs, took the Field contract in his own name, they to have an interest in it; also to prove by parol evidence that the plaintiffs agreed after the contract was made with Field by the defendant, and before and at the time of making the contract between the parties to the suit, to take an interest in the Field contract to the extent of three thousand tons, and to rely for payment upon Field, as specified in the written contract.
The evidence was objected to and excluded. We think it should have been received. In no way would it have varied or contradicted the writing signed by the plaintiffs. That writing contained one side of the contract only. It contained a promise by the plaintiffs, but none by the defendant. In support of their action the plaintiffs must have relied upon an implied promise. The case shows that they neither proved nor attempted to prove an express one. When, in support of an action of assumpsit, the plaintiff relies upon an implied promise, can there be any doubt that the defendant may repel the implication by parol evidence of an express promise, accepted by the plaintiff, which is inconsistent with the one implied by law ? We do not say such would be the law if the plaintiffs had obtained from the defendant ail *237express written promise on which they relied in support of their action. But such is not the fact. They had no written promise from the defendant. Tomato out a prima facie case they were themselves obliged to rely upon parol evidence. The first step taken in the trial was to call one of the plaintiffs, and have him testify that the defendant was the party with whom they dealt, and to whom they delivered their ice, apparently intending thereby to lay the foundation for an implied promise, which would, prima facie, support their action. Under these circumstances we cannot doubt that it was competent for the defendant to prove by parol evidence what his exact promise was, and to show, if he could, that it was contingent; that it was dependent upon whether or not he should collect his pay of Field; that the plaintiffs were to share the risks as well as the benefits of his contract; that they were to rely upon Field’s ability to pay for the ice which they should furnish, as the defendant would be obliged to do for the ice which he should furnish. Such an agreement is not improbable. The plaintiffs were to receive for their ice the- full price paid by Field. The defendant would receive no profit upon it. Why, then, should he insure their pay? Of course it would be competent for him to do so. But looking at the transaction in the light of what is probable and what is improbable, it seems as if such could hardly have been the fact. But all we mean to say is that a different understanding, such an understanding or agreement as the defendant offered to prove, is by no means improbable, or in conflict with any writing signed by the defendant; or, in conflict, even, with the writing which the plaintiffs signed. We think the evidence should have been received. We do not rest our decision upon the ground that the evidence was admissible to explain any supposed ambiguity in what was written. We hold that it was admissible to supply important facts in relation to which'the writing was entirely silent. Admitted for such a purpose, the rule excluding parol evidence to vary or contradict written documents would not be infringed. The -evidence would in no way vary or contradict any thing that was •written. Davenport v. Mason, 15 Mass. 85 ; Pierce v. Woodward, 6 Pick. 206; Hogins v. Plympton, 11 Pick. 97; Tisdale *238v. Harris, 20 Pick. 9; Kinney v. Whiton, 44 Conn. 262; Lindley v. Lacey, 17 C. B. (N.S.) (112 E. C. L.) 578 ; 1 Gr. Ev. § 284, a. ; Stephen on Ev. Art. 90, (2).
Hxcejptions sustained. Hew trial granted.
Appleton, C. J., Barrows, Daneorth, Peters and Symqnds, JJ., concurred.