Opinion by
Beeber, J.,The first contract made by these parties was that the plaintiff would appoint the defendant his deputy and allow him to do all the work which the law required to be done and to receive all the pay, provided defendant would use his political influence to secure plaintiff’s appointment as mercantile appraiser. If the plaintiff, after his appointment had been secured by defendant’s political influence, had refused to appoint defendant his deputy and to allow him to receive the pay, it is clear, under the numerous authorities cited by appellant, that defendant would have no right of action against the plaintiff. The reason is that the consideration which the defendant gave plaintiff for this promise, the breach of which would be the cause of action, which consideration was the exercise of the defendant’s political influence resulting in the appointment to the office, was not a legal one. The defendant under such circumstances would be required to prove a legal consideration given by him to the plaintiff for the plaintiff’s promise to appoint him, and when it appeared that that consideration was the exercise of defendant’s political influence, he would be defeated by the operation of the rule, which prevents a plaintiff from recovering where he requires the aid of the illegal transaction to establish his case. The test is whether the consideration for the promise, the breach of which is the cause of action, is a legal or illegal one, and when it appears that it is illegal the action falls.
But this was not the contract upon which the plaintiff brought suit. The undisputed evidence shows' that after the appointment was made, it was discovered, upon consulting counsel, that plaintiff could not legally appoint a deputy. Plaintiff proved that it was then agreed between them that plaintiff should serve as appraiser and that defendant should go with him and assist in the performance of the duties, for which assistance plaintiff was to pay defendant whatever was right. *526When the pay was due, plaintiff gave defendant an order upon the county treasurer to pay defendant the balance due plaintiff as mercantile appraiser, upon which order defendant collected the money. Plaintiff testified that when he gave this order he instructed defendant after deducting expenses and the amount due him for his assistance, to pay the balance on account of an indebtedness of the plaintiff. The defendant failed to pay the balance on account of plaintiff’s indebtedness, but kept it for his own use, and it was this failure to pay the balance in this way that was the plaintiff’s cause of action. It is true defendant denied that there was any such instruction, but the jury have found against him. We cannot see why the plaintiff is precluded from recovering from the defendant for this breach of his implied undertaking to pay the balance as directed by plaintiff. The plaintiff did not require the aid of the original illegal transaction to prove his case. In the cases cited on this subject it is frequently said that the plaintiff will fail if the evidence shows that he needs the aid of the illegal transaction to establish his case, but we cannot take this to mean that the mere introduction of evidence of the illegal transaction defeats the plaintiff. The question still remains, does plaintiff need the evidence to prove his ease. There are many cases which hold that a new contract, founded on a new consideration, although in relation to the same subject-matter respecting which there had been unlawful transactions between the parties, is not itself unlawful: Armstrong v. Toler, 24 U. S. 258; Lestapies v. Ingraham, 5 Pa. 71; Thomas v. Brady, 10 Pa. 164. This being the rule we think the plaintiff can recover for the defendant’s failure to pay the money as directed, even though he and defendant made an illegal contract to secure the plaintiff’s appointment as mercantile appraiser. The assignments of error from the seventh to the twelfth inclusive are overruled.
The rejection of the evidence embraced in the second and third assignments of error was proper. This evidence was offered as a set-off to plaintiff’s claim, but it is clear that if plaintiff’s evidence was accepted by the jury a set-off is inadmissible, because the defendant is found, in plain language, to have violated a special trust, which was to apply the money on a certain account, and of course he could not apply it to his own use by pleading a set-off. If the defendant’s evidence of the *527contract had been accepted there could be no recovery of any amount against him, and therefore nothing against which there could be a set-off. The evidence embraced in the first assignment was merely cumulative, looking at it in the light most favorable to the defendant, and that, too, upon an immaterial matter, as there was no substantial dispute as to the amount of services defendant rendered. Even though we are convinced, which we are not, that it was error to exclude this evidence, we would not reverse on that account, for, as we have said, it was only cumulative evidence upon an immaterial and undisputed question. Nor can we see an error in the refusal of the court to admit the evidence, rejection of which forms the fifth assignment. It did not contradict, or tend to contradict, any material evidence of the plaintiff. The refusal of the court to affirm the third point of the defendant, which asked it to say that as the burden of proof lay on the plaintiff, and as his case was supported by the oath of the plaintiff alone, and contradicted by that of the defendant, he had not made out his case by a preponderance of evidence and therefore there could be no recovery, forms the sixth assignment of error. We think it was right to refuse to affirm this point. The preponderance of evidence is not determined by a mere count of the witnesses. The learned trial judge told the jury that plaintiff must prove his case by a preponderance of evidence and this was as far as he was required to go in this respect. It is his duty in the first instance to decide whether there is enough evidence to be submitted to the jury, and having once submitted it to them, it is their duty to decide on which side lies the preponderance. This depends so much on the credibility of the witnesses that the proper tribunal to decide it is the jury. The first, second, third, fifth and sixth assignments are overruled.
The fourth assignment is to the admission of evidence as to the relative financial responsibility of the parties to the action. Defendant was a witness in his own behalf. On his cross-examination he said substantially that the plaintiff, at the time of his appointment, was insolvent or worth nothing. He was then asked on further cross-examination whether he himself was not at that same time worth more than plaintiff and worth ■several thousand dollars, which he admitted to be true. It is evident that these questions were asked to secure answers which *528would, affect the credibility of defendant’s evidence in chief, to the effect that plaintiff had agreed to allow him, the defendant, to have the money sued for to help pay the big rent defendant was then paying. The rule is undoubted that a party who has been examined in chief as a witness in his own behalf may be cross-examined as to any matters which go to affect his credibility: Huoncker v. Merkey, 102 Pa. 462. It may be conceded that tlie evidence in a case may be such that the credibility of a part of it would be seriously affected by showing the relative financial responsibility of the parties to the action, but we do not think tins case was such an one. It is common practice, where several creditors are asserting claims against a common debtor, for some of them to show that the claims of others, based upon an alleged loan, are probably bogus, by showing that' the creditors claiming to have made the loan were insolvent at the time it was alleged to have been made: Hirsh v. Wenger, 182 Pa. 246. The same kind of proof will be admitted where there is a question of fraud, or undue influence in the case: Stevenson v. Stewart, 11 Pa. 307; Hartman v. Shaffer, 71 Pa. 312; Glessner v. Patterson, 164 Pa. 224. The plaintiff got the benefit of the principle established by these cases when he proved by cross-examination of the defendant that he, the plaintiff, was worth nothing or insolvent at the time when defendant alleged that plaintiff agreed that defendant was to be given this money to pay his heavy rent. Whatever of improbability was imparted to defendant’s evidence in chief by the insolvency of the plaintiff was thus before the jury, but to permit the plaintiff to go further and prove the probable wealth of the defendant would not, in our opinion, increase that improbability. We do not think the trial judge could presume that the possession of property by the defendant rendered it improbable that plaintiff would have given him money to pay big rent, for it is not at all uncommon for men of considerable wealth to be sometimes in pressing need of ready money. We think such evidence is excluded by the principle established in Woods v. Gummert, 67 Pa. 136. In that case it was held, in a suit by the plaintiff to recover money which he alleged that he had advanced to the defendant, it was inadmissible to prove that an execution, issued against the plaintiff some time before the advances were alleged to have been made, *529had been returned nulla bona. It was there said that when a suit is brought to recover money advanced it should not be inferred, from the cases allowing the widest latitude in the admission of evidence in questions of fraud, “ that it is competent to the defendant to give evidence of the pecuniary inability of the plaintiff and thus raise an issue entirely collateral. What legitimate inference in such a case can be drawn from the insolvency of the plaintiff? Men heavily indebted and even keeping their creditors at bay, often have large transactions in borrowing and lending and are possessed of considerable sums of money. If the defendant is allowed to show that the plaintiff owes debts which he does not pay, the plaintiff may certainly rebut the evidence by showing that he has a good defense to them. Thus, innumerable collateral issues might be introduced.” So in this case it may be pertinently asked, what legitimate inference can be drawn from the fact that the defendant was possessed of considerable property? Men of considerable wealth are often so involved in their business that ready money is an imperative necessity. If plaintiff is to be allowed to show that defendant was possessed of considerable property, surely defendant may rebut such evidence by showing that he was in pressing need of ready money, and thus innumerable collateral issues would be introduced to the confusion of the real issue. The prejudices of a jury are too easily aroused to justify the introduction of such evidence except in cases where it is clear to the judicial mind that it would affect the credibility of other evidence. For these reasons we are compelled to sustain the fourth assignment of error.
Judgment reversed and venire facias de novo awarded.