Mr. Justice Green
delivered the opinion of the Court,
We think it can not be questioned that the deed from Jackson to Joseph M. Payne of June 1st, 1872, and the mortgage in suit from J. M. Payne to Jackson of same date, for securing the payment of $9,000, were intended by all the parties to *78represent, and actually did represent, an arrangement for securing to Jackson the payment of a debt due by' George Payne to him. The legal title to the premises was at that time in Jackson. He was willing to convey the title to George. Payne or to any one he might name, and take a mortgage from the grantee of the title to secure his debt. All of this was testified to by Jos. M. Payne, was notcontradictedby Jackson, and is corroborated most strongly by Jackson’s letters of March 2d, and March 17th, 1871, to George Payne, and December 8th, 1871, to Jos. M. Payne. There was no proof of any independent transaction between Jackson and J. M. Payne and no proof of any indebtedness from J. M. Payne to Jackson other than that derived from the mortgage in question. The object of the arrangement manifestly was, the vesting of the title in some one representing George Payne, and at the same time securing to Jackson the payment of the debt which George Payne owed him in as effective a manner as was possible, by a mortgage on the premises described in that instrument. This being the true situation of the parties, it is clear that the matter embraced in the offer of testimony covered by the first assignment of error was competent, because it tended to disclose, in connection with the evidence by which it was to be followed, the character of the original transaction between Jackson and George Pajme. We think it also illustrates the correctness of the answer to the defendant’s 1-|- point covered by the sixth assignment. That.is, upon the theory that the mortgage in suit was given to secure a debt of George Payne, it should not include more than was legally due, and any excess over that amount could not be recovered although the mortgage given by J. M. Payne was the obligation of another person. It seems to us also that there was sufficient evidence to show that the original conveyance by George Payne to Jackson was intended merely as a security for a debt, and not as an absolute deed. It would not be possible to understand the letters and above all the ultimate transaction with Jos. M. Payne except upon that theory.
But the court went further than this and referred to the jury the question whether there was a bonus of $2,000 exacted from J. M. Payne, and added to the amount of the real debt making it $10,000 instead of $8,000. In support of this allegation there was no testimony but the unsupported oath of Joseph M. Pa3'ne the defendant. It was absolutely denied by the oath of the plaintiff and the case stood on this subject upon the oath of the plaintiff and the mortgage on one side, and the unsupported oath of the defendant on the other.
The letter of the plaintiff of March 2d, 1871, written more *79than a year before and in which the plaintiff said “the amount is something over $8,000 ” contained a mere casual and indefinite statement, not purporting to be precise, and is of no weight whatever when contrasted with the solemn and deliberate'act of giving a mortgage for a different amount fifteen months later. There-was neither allegation nor proof of any fraud, accident or mistake, in the execution of the mortgage, nor of any promise then made as to its use which was subsequently violated. We have several times held, that in these circumstances parol evidence is not admissible to contradict or vary written instruments. We have also held that in any case where such evidence is admissible, if there is but the unsupported oath of one of the parties to the instrument on the one side, and the opposing and contradictory oath of the other party, together with the words of the instrument, on the other side, such unsupported oath is not sufficient to justify the reformation of the instrument, and in such case the evidence should not be submitted to the jury. In Phillips v. Meily, 10 Out., 536, both these phases of the general subject were carefully considered and authoritatively ruled, and in our subsequent reflection and experience have confirmed us in the views there expressed. Authorities to the same effect are Thorne v. Warfflein, 4 Out., 456, 519; Nicolls v. McDonald, 5 Id., 514; Smith v. Nat. Life Ins. Co., 7 Id. on p. 184; North and West Branch Railway Co. v. Swank, 9 Id., 555. In the case of Juniata Building Association v. Hetzel, 7 Out., 507 our brother Tbtjnkey expresses our convictions fully in the following language: “ The defendant seeks to escape liability on the ground of a verbal agreement that induced him to sign the bond, because it shifted his position, as it appears on the face of the bond, to a secondary one which cannot be reached until after exhaustion of another security. He sets up an equitable defence and contends that if the testimony of himself stands alone, and is contradicted by a dozen witnesses it remains for the jury to determine the facts involved. This is true as respects every question of fact in any claim at law, but every right founded upon a claim which is strictly equitable whatever the form of procedure, should be supported by evidence that would satisfy a chancellor. If a fact be averred in the bill and denied in the answer it cannot be pretended that the uncorroborated testimony of the plaintiff would be sufficient to establish such fact in a court of equity.” As the attempt in the present case is to reform a mortgage by showing that it was given for an amount different from that which is expressed on its face, the contention comes clearly within the purview of the foregoing observations which are repeated in 9 Out. on p. 501-2. In the portion of the *80charge covered by the fourteenth assignment the learned court below submitted to the jury the determination of the question as to the amount due upon the mortgage as originally given, when in our opinion they should have given a binding instruction that it must be taken as $9,000, the amount stated in the instrument. In this we think there was error, and we therefore sustain the fourteenth assignment. The argument that the mortgage was obtained by duress we regard as without merit in any point of view. The first and sixth assignments are not sustained.
As to the second, third and fourth assignments we can not understand why declarations or acts which transpired between the plaintiff and the defendant in the present action, are not admissible, even though they occurred in the presence of George Payne. They are admissible because they are the acts and declaration of these parties, and thej are no less the acts and declarations of these parties in every sense in which the law can regard them, whether any other person was present or not. We think that conversation with George Payne in his life time, or acts then done with him, can not loe proved by Jackson in this case because it was George Payne’s debt for which the mortgage in suit was given, and the plaintiff is the survivor of the transaction between hi in and George Payne, whose rights in this respect have devolved upon the defendant. But that circumstance can not defeat the right of the plaintiff to testify as to what took place between himself and the defendant, whether George Payne was then present or not. The defendant is alive, is a competent witness, and can testify fully in relation to the same matters. Between them there is no inequality if both may testify to the same matters occurring when both were together, but there would be very serious inequality if the defendant may, and the plaintiff may not, testify as to such matters. We sustain these three assignments in so far as they cover the exclusion of evidence by the plaintiff as to acts and declarations occurring between the plaintiff and defendant in the presence of George Payne. In other respects they are not sustained.
The fifth assignment is unimportant while, if the case stood only upon the mortgage of 27th February, 1849, a presumption of payment would arise in 1872, yet if the mortgage of 1872 were given in whole or in part for the same debt, that presumption would necessarily be thereby rebutted. The assignment is not sustained.
As to the seventh, ninth, tenth and twelfth assignments we do not feel that we can say there was no evidence, or not more than a scintilla, tending to prove at least negligence on the part of the plaintiff in the matters referred to, and hence we *81can not sustain them. Wé do think, however, it would have been proper for the court to define with more accuracy the duty of the plaintiff in the premises, and to explain what acts or omissions would constitute negligence, and even to refer to some extent to the testimony on both sides on these subjects. Merely naming the witnesses on each side, or some of them, and telling the jury that counsel have discussed it and that they must find a fair and impartial verdict, is not an adequate mode of presenting such matters to a jury. It does not enlighten them as to what their duties' are, nor does it furnish them with any sufficient guide for their action in considering and passing upon' a mass of testimony the meaning and effect of which may not be very intelligible to the ordinary mind without explanatory comments by the court. As the case must be tried again, we do not desire to discuss the testimony, nor do we feel called upon to reverse upon any of the assignments we are now considering, trusting that what we have said in a cautionary way may receive the consideration of the court on another trial. These assignments are not sustained.
As to the eighth and thirteenth assignments we have serious question whether there was even a scintilla of evidence upon which the plaintiff can be properly charged with culpable negligence for not prosecuting the suit against Freck with due diligence, and thus becoming chargeable with the consequences of an actual recovery and collection of the claim against him. Very able and experienced counsel were employed to commence and prosecute the claim. An action was brought in due season. There was delay in getting it tried, but it is not easy to see how the plaintiff is responsible for that kind of delay. The cause was repeatedly on the trial list but not reached. The time of the court was occupied in an extraordinary degree by the trial of very exciting and important criminal cases. It is a hard measure of liability for a private citizen to be held responsible for delay in collecting a claim, when the delay was not of his own production. A judgment was recovered but it was five years after suit brought, and in the mean time Freck, the defendant, became insolvent and the claim was not collected. We will not reverse on these assignments, because what was said by the court was hypothetical upon assumed facts which if true would justify the conclusions expressed. But we have much doubt whether all the actual facts in evidence were sufficient to justify a conclusion of liability for negligence. Upon another trial we think the circumstances which would constitute liability by reason of negligence should be defined with more precision in order that the jury may understand the duty to which the plaintiff was subject in this regard, and in *82what respects, if any, he disregarded it to the injury of the defendant. The case is not the same as if the plaintiff already held a judgment against Freck for the claim in question and failed to take proper measures for its collection. But it includes the necessity of first obtaining a judgment and for that, after a suit was brought, other persons, some of them officers of the law. whom the plaintiff could not control, are in part responsible, and the question is whether the delay was due entirely to the fault of the plaintiff, or whether by greater exertions, such as a person would use in prosecuting his own claims, a speedier judgment might have been obtained, and if so, whether it would have been in time to collect the claim.
We can not say there was error in the language covered by the fifteenth assignment. It is perhaps amenable to some of the foregoing criticism, but in itself it is .not error.
Judgment reversed and new venire awarded.