¶1Oral evidence, tending to establish an independent collateral agreement as a condition precedent to a contract becoming operative, is not evidence tending to vary or impeach a written instrument; and its exclusion constitutes reversible error. Benton v. Martin, 52 N. Y. 575; Burke v. Delaney, 153 U. S. 228.
¶2Present: Gildersleeve, Fitzgerald and Davis, JJ.
¶3Judgment reversed and new trial ordered, with costs to appellants to abide event.