The plaintiffs assert that the garnishee is indebted, to their debtor, John Gray, by force of a written contract entered into between, and signed and sealed by, the garnishee and said Gray, on the 10th of February, 1851, a copy of which appears in the bill of exceptions;, and they have resorted to the remedy by garnishment, (instituted before the Code went into effect,) to reach and recover that, indebtedness. By that remedy, they are “merely substituted to the rights” of their debtor, and cannot reach the demand, if, from its character, their debtor could not have maintained debt or indebitatus assumpsit upon it. — Hall v. Magee, 27 Ala. 414; Lundie v. Bradford, 26 Ala. 512 ; Cook v. Walthall, 20 Ala. 334; Loftin v. Shackelford, 17 Ala. 455; Hazard v. Franklin, 2 Ala. 349; The Br. Bk. at Mobile v. Poe, 1 Ala. 396.
The legal effect of the contract is, that Nesbitt should pay Gray, in the installments, and at the times specified therein, six thousand dollars, “in iron at 5 cents per pound, and castings at 4 cents per pound, to be delivered at the place or places where made;” with a condition superadded, givingtoNesbitt the privilege of discharging it in a specified “way;” that is, by doing the two things specified, to-wit, paying 'the note for $941 to the State, and giving “his obligation for three thousand dollars,” payable in money, in the installments, and at the times specified. That privilege was merely for the benefit of Nesbitt, and did not put him under any obligation to pay the note to the State, nor to give his obligation for the three thousand dollars to be paid in money. The only “way” in which he could manifest an election to avail himself of the privilege, was by doing both the things prescribed; that is, by paying the note to the State, anfl giving his obligation for the three thousand dollars payable in money. And unless both of these things were done by him within a reasonable time after the contract was made, he lost the privilege, and his obligation to pay the six thousand dollars in iron and eastings, at the times and prices specified, is precisely the same as if the privilege had not been given by the contract to discharge it in the prescribed “way.” Gray has no right, under the contract, to hold *74the garnishee liable for the three thousand dollars, for which the latter had the privilege to give his obligation, unless that obligation has been given. , And as it seems to be a conceded fact, that no such obligation has been given, the garnishee is not liable for the three thousand dollars; but, if liable at all, his liability is for apart or the whole of the six thousand dollars first mentioned in the contract, to be paid in iron and castings as therein shown.— Plowman v. Riddle, 7 Ala. 775; Love v. Executors of Simmons, 10 Ala. 113.
Supposing him liable for a part or the whole of that six thousand dollars, the question is, could Gray have maintained debt or indebitatus assumpsit to enforce that liability. We think it clear that he could not. An action by him, to enforce such liability, must have been an action on the contract itself. — Hall v. Magee, 27 Ala. 414; Merriweather v. Taylor. 15 Ala. 735. Indebitatus assumpsit could not have been supported, because (if for no other reason) the contract is under seal. — See Cochran v. Tatum, 3 Monroe, 405. Debt could not have been sustained, because each installment was to be paid in iron and castings at a specified price. — Scott v. Young, 5 Ala. 475; Jolley v. Walker, 26 Ala. 690; Love v. Executors of Simmons, 10 Ala. 113; Carlisle v. Davis, 7 Ala. 42; Wilson v. Jones, 8 Ala. 536.
In an action on the written contract, or to enforce it, parol evidence is not admissible, to add to, contradict, or vary its terms. — Cole v. Spann, 13 Ala. 587; West v. Kelly, 19 Ala. 353; Dixon v. Barclay, 22 Ala. 370; Phillips v. Longstreth, 14 Ala. 337.
When, as in this case, the answer of the garnishee is controverted by the oath of the plaintiff in attachment, “the issue is, of necessity, confined to a general allegation that the garnishee is indebted to the defendant in attachment, either generally, or in a larger sum than admitted by his answer.” — Myatt v. Lockhart, 9 Ala. 91. See, also, 2 Ala. 349; 1 Ala. 396; 17 Ala. 455.
The issue, as made up under the direction of the court in this case, was not the proper issue. In directing that issue to be made up, the court erred in requiring the garnishee *75to join issue on tbe allegations of tbe plaintiff in relation to tbe written contract between Gray and tbe garnishee. Those allegations, if true, do not show any indebtedness which can be reached by the garnishment.— See authorities above cited.
The court also erred, in admitting those portions oí the evidence of the witness McLain, embraced by the first three exceptions taken thereto by the garnishee. That evidence tended to contradict, add to, or vary the written contract; and should, therefore, have been excluded on the objections made thereto by the garnishee.
It is unnecessary to consider or decide whether the court below did not err in its other rulings embraced by the assignments of error; because the views above expressed by us are decisive of the case against the plaintiff.
For the errors above noticed, the judgment of the court below is reversed, and the cause remanded.