In Russell v. Southard (1851) 53 U.S. 139, there was between the fraudulent transaction and the commencement of the suit a lapse of nineteen years and eight months, and it was held that that was not sufficient, the court saying (p. 155): "The absence of all valuable consideration for the surrender of the equity, and the circumstances of distress under which it was made, and which, so far as appears, continued to exist down to the filing of the bill, coupled with the conviction, which we think Russell mistakenly entertained, that his rights were probably destroyed, must prevent us from allowing the lapse of time to be a positive bar." In dealing with the question of the admissibility of parol evidence to establish the relation of mortgagor and mortgagee in the face of an unambiguous memorandum which was clearly designed to manifest a conditional sale, the Supreme Court of the United States uses this language: "It is insisted, on behalf of the defendants, that the question is to be determined by inspection of written papers alone, oral evidence not being admissible to contradict, vary, or add to, their contents. But we have no doubt that extraneous evidence is admissible to inform the court of every material fact known to the parties when the deed and memorandum were executed. This is clear both upon principle and authority." Mr. Justice Curtis delivering the opinion of the Court, sayid: "It is the doctrine of this Court that when it is alleged and proved that a loan on security was really intended and the defendant sets up the loan as a payment of purchase money, and the conveyance as a sale, both fraud and vice in the consideration are sufficiently averred and proved to require a court of equity to hold the transaction to be a mortgage." The importance of the consideration in determining whether the transaction was a sale or mortgage is given emphasis in Russell v. Southard, in the following words: "In examining the question whether the transaction was a sale or mortgage, it is of great importance to inquire whether the consideration was adequate to induce a sale."