Two of the rulings made at the trial were erroneous.
1. The plaintiff, as part of his case, and for the purpose oí proving the extent of his damages by the breach of the contract declared on, offered evidence to show that he was to receive, as part of his compensation for performing the work for the defendants under the alleged contract, an assignment of their claim against the Boston & New York Central Railroad Company for damages for locating their railroad across the land of the defendants. To prove the value of this claim and the loss he had sustained by reason of the omission of the defendants to assign it to him, he offered a paper purporting to be written by the register of deeds for the county of Norfolk, stating the substance of an assignment and conveyance made of said claim and other property to the trustees of an association, in consideration of the sum of $25,275. To rebut the inference which might be drawn from this evidence as to the value of such claims, the defendants offered to prove that it was in fact worthless, and that nothing was paid or agreed to be paid therefor by the association to which it was assigned. This evidence was relevant and material. It tended directly to rebut the evidence which had been offered by the plaintiff. Nor was it objectionable on the ground that it was in its nature secondary, which is the reason assigned in the exceptions for its rejection. The purpose of it was only to show that no part of the consideration named in the certificate as paid to the defendants was given for the assignment of the claim for land damages. To prove this, parol evidence was competent. The consideration stated in a deed is only prima facie evidence. The real sum paid may be proved by any evidence, either oral or written; the rule excluding parol evidence to vary or control a written document not being applicable to the statement of the consideration in a deed or other instrument. Wilkinson v. Scott, 17 Mass. 249. Gale v Coburn, 18 Pick. 397. Miller v. Goodwin, 8 Gray, 542.
2. The evidence offered for the purpose of showing that the plaintiff had suborned a witness to testify falsely in support of his claim against the defendants, and, in connection therewith, *452that in procuring such false testimony he had acted under an assumed name, was clearly competent and ought to have been admitted. These facts were in the nature of admissions implied from the conduct of the party that his claim against the defendants was false and unjust. The inference is a reasonable and proper one, that a person having an honest and fair debt which he claims to be due will not endeavor to support it by falsehood and fraud; and the fact that he resorts to such means of proof has a tendency to show that he knows he cannot maintain his suit by evidence derived from pure and incorrupt sources. Truth does not ally itself with falsehood, but falsehood will often endeavor to make it appear that truth is on its side. When therefore it is shown that a party to a suit has sought to suborn wit- • nesses to swear falsely in his behalf, and has been guilty in his own person of fraud and deceit in the maintenance of his action, such evidence is competent, as an admission of the falsity or fraudulent nature of the claim. 1 Greenl. Ev. § 196. Morgan v. Frees, 15 Barb. 352. On the same ground it is held that the suppression of documents in a party’s possession or control is an admission that their contents are unfavorable to the party suppressing them, and will not sustain his case. James v. Biou, 2 Sim. & Stu. 600, 606. Owen v. Flack, Ib. 606. On these grounds, we are of opinion that the defendants are entitled to a new trial. Exceptions sustained