A mortgage is a mere security for the payment of a debt. It forms no part of the debt itself, and therefore may be released or discharged without affecting the validity of the debt. This is not denied by the counsel for the plaintiff, but it is contended that as the mortgage deed was under seal no parol agreement should be received as evidence of its discharge. To this argument we cannot assent. In the case of Barrelli & Martin v. O’Conner, 6 Ala. Rep. 617, this court held, that evidence might be received of an executed parol contract in discharge of a contract under seal. The decision is well sustained by authority, and in our judgment recognizes the correct rule. The evidence was therefore properly admitted and it justified the charge given by the court to the jury, for it tended to show a new and distinct contract with the mortgagor, by which the girl Harriett was to be discharged from the mortgage in consideration of the delivery of the boy Sam, who was to be retained by the mortgagee as a pledge for the security of the debt, in lieu of Harriett, who was conveyed by the mortgage for the same purpose. Whether the evidence was sufficient to establish such a contract or not is a question we cannot review — the sufficiency of the evidence is a matter purely for the jury, and if they erred in their conclusion of the fact, the plaintiff could only obtain relief by *741a motion for a new trial. Bat that the evidence was admissible ¡and the charge appropriate, as applied to it, we entertain rao doubt.
iia the case of Ranley v. Rice, 10 Metc. 7, it is said if a mortgagor of a chattel make a new and distinct contract with the mortgagee, by which he delivers to him not only the mortgaged chattel, but also other chattels not mortgaged, to be held by the mortgagee as a security for the debt, the mortgagee by such new agreement becomes the pawnee of all the chattels so delivered, as well those previously mortgaged as those that were not. The propriety of this decision is manifest when we reflect that the title to personal property may pass .by parol, and the fact that the instrument that conveys the ¡title to the owner is under seal, cannot restrain or control his right or capacity to convey it by parol or mere delivery. A -mortgagee may then release his mortgage by a sufficient parol agreement, although the mortgage be under seal and the debt unpaid.
2. The writ in this case was issued twenty-four days before it was served. The sheriff took possession of the slave, ¡as ¡the plaintiff had made the affidavit and given the bond required by the statute, and the defendant on the day of the service of the writ executed a replevy bond in the usual form. '0m ¡the trial the plaintiff requested the court to charge the jury that the replevy bond estopped the defendant from denying ¡that ¡he was in possession of the slave when the writ was is.sued. The plaintiff is bound to prove that his cause of action occurred before the suit commenced — therefore, it was incumbent on him to show that the defendant was guilty of an ¡unlawful detainer anterior to the time of issuing the writ. The ¡bond, however, is an admission, that he was id possession at the '-tii-oae the writ was executed, and is therefore a circum■stance tending to prove that the defendant was in possession anterior to that time, and in the absence of all other proof, the jury -might well find that the defendant was in possession at the date of the writ. But this may be repelled by proof to the contrary, as the bond contains no recital showing that the defendant was in possession previous to the day the writ was -executed. The bond estops the defendant from denying that the defendant was in possession at the date of the seiheice of *742the writ, but as no admission or recital is contained in it showing possession anterior to that time, it cannot preclude the defendant from showing that at the date of the writ he had not the possession and was not guilty of the unlawful detainer.
We are satisfied that the Circuit Court ruled the law correctly, and the judgment must therefore be affirmed.