¶2If the testimony, which plaintiffs contend was erroneously rejected, had been received, it would, together with the evidence introduced, have tended, (upon the construction most favorable to plaintiffs,) to establish a state of facts substantially as follows, viz. : That on the second day of September, 1871, plaintiffs being engaged in a general foundry business at St. Paul, defendant promised to supply them with all the Lake Superior pig iron wanted by them in their said business, from said date until December thirty-first, next ensuing, at specified prices, and that plaintiffs simultaneously promised to purchase of defendant all of said iron, which they might want in their said business, during the time above mentioned, at said prices. If this state of facts establishes any contract, it is a contract of •mutual ■promises. That is to say, the sole consideration for defendant’s promise to supply, is plaintiffs’ promise to purchase, and vice versa.
¶3The general rule (with exceptions not important in this instance,) is, “ that a promise is not a good consideration for a promise, unless there is an absolute mutuality of engagement, so that each party has the right at once, to hold the other to a positive agreement.” 1 Parson’s Contracts, 449, and note z.
¶4Upon the foregoing state of facts, the .engagement of plaintiffs was to purchase all of said pig iron, which they might want in their said business during the time specified ; but they do not engage to want any quantity whatever. They do not even engage to continue their business. If they. see fit to discontinue it on the very day on which the supposed agreement is entered into, they are at entire liberty to do so at their own option, and, whatever might have been defendant’s expectation, he is without- remedy. In other words, there is no absolute engagement on plaintiff’s part to “ want,” *538and of course no absolute engagement to purchase any iron of defendant.
¶5Without such absolute engagement on plaintiffs’ part,'there is no “ absolute mutuality of engagement,” so that defendant “ has the right at once to hold ” plaintiffs “-to a positive agreement.” '■
¶6Upon these grounds we are of opinion that the testimony excluded was properly excluded, since it did not tend to establish a valid contract on the part of defendant, and was therefore immaterial.
¶7The testimony being excluded, there was nothing for the jury, and the action was rightly dismissed. >
¶8This case may be looked at from, another point of view with like results. Plaintiffs’ promise was the sole consideration for defendant’s promise. To be a sufficient consideration it is necessary that plaintiffs’ promise be a benefit to defendant, or an injury to plaintiffs. (1 Parsons on Contracts, 431.) .But so long as, for the reasons before given, plaintiffs are not bound to do anything whatever by virtue of their promise, the promise cannot be such benefit or injury.
¶9Judgment affirmed.