delivered the opinion of the Court:

At the threshold of the case we are met with the contention that it was error to permit the plaintiff, in an action of assumpsit, to recover upon an unexecuted sealed instrument. That the previous negotiations between these parties became merged in that instrument cannot be gainsaid. Where the terms of a contract have been reduced to writing and signed by the parties, neither party can abandon the instrument and resort to the verbal negotiations which were preliminary to its execution, since “all previous negotiations and verbal statements are merged and excluded when the parties assent to a written instrument as expressing the agreement.” Merchants’ Mut. Ins. Co. v. Lyman, 15 Wall. 664, 21 L. ed. 246; DeWitt v. Berry, 134 U. S. 306, 33 L. ed. 896, 10 Sup. Ct. Rep. 536; Magruder v. Belt, 7 App. D. C. 303; Bergin v. Williams, 138 Mass. 544. In the present case, there was no contract of marriage until the contract under seal was executed. Everything preceding it was merely tentative and preliminary. That contract crystallized the previous negotiations between the parties. Counsel for the plaintiff answer that, conceding all this, still they may rely upon “repeated promises^ made by and between the defendant *344and plaintiff after the execution of the agreement,” but they fail to point to any evidence tending to show that the written instru7 ment ever was abandoned or modified. McKay v. Darling, 65 Vt. 639, 27 Atl. 324. The conduct of the parties following the execution of that instrument amounted to nothing more than a recognition of it. The question is, therefore, whether the defendants motion for a verdict upon count No. 1 should have been granted.

The rule of law is that where a special contract remains executory, the plaintiff must sue upon it. Marine Ins. Co. v. Young, 1 Cranch, 332, 2 L. ed. 126; Magruder v. Belt, 7 App. D. C. 303; Brown v. Commercial F. Ins. Co. 21 App. D. C. 335. In Magruder v. Belt, the court said: “A simple contract and a contract under seal between the same parties cannot both subsist for the same subject-matter or obligation. The contract under seal,'being of superior dignity and solemnity in the contemplation of law, will merge the simple contract. * * * There will be a merger of the simple contract, whether the parties wish it or not, for the two contracts are incompatible, and except where one is intended to be simply collateral to the other, they cannot subsist together for the same thing, and the higher must prevail. Price v. Moulton, 10 C. B. 561, 20 L. J. C. P. N. S. 102, 15 Jur. 228; Leonard v. Hughlett, 41 Md. 380. The action should have been debt or-covenant upon the sealed contract.” In Young v. Preston, 4 Cranch, 239, 2 L. ed. 607, it was ruled that “whenever a man may have an action on a sealed instrument, he is bound to resort to it.” When, however, a special contract has been fully executed according to its terms, suit may be brought upon it, or in assumpsit upon the common counts. In either case the contract will determine the rights of the parties. Dermott v. Jones, 23 How. 220, 16 L. ed. 442, and 2 Wall. 1, 17 L. ed. 762. The rule here invoked is not an arbitrary rule, but, on the contrary, one founded in reason and justice. If parties enter into a contract of the dignity and solemnity of the one here involved, the party seeking damages for the breach of that contract should declare upon it. The plaintiff in the present case, by deliberately abandoning the *345second count in her declaration, relied upon the count which sets up a simple contract. Her proof showed the existence of a different contract, one that had superseded the former, and which would not support the declaration as it then stood.

But, it is said, the defendant by bis inconsistent positions is estopped to raise this question. We are unable to accept this contention. The record fails to show upon what ground the defendant, at the close of plaintiff’s evidence, moved for a directed verdict on the second count. It does show, however, that the plaintiff, without waiting for a ruling by the court, voluntarily abandoned that count. Surely the defendant had a right, before introducing his evidence, to obtain a ruling from the court upon the sufficiency of either or both of the counts of the declaration. If the plaintiff elected voluntarily to abandon a count, it was no fault of the defendant. Nor do we find anything unusual in the fact that, defendant’s prayer for a directed verdict on count No. 1 having been denied, he submitted other prayers inconsistent therewith. It was the duty of counsel to protect their client’s interests to the fullest extent, and they were well within their rights in submitting these prayers. We find none of the elements of estoppel present.

The judgment must be reversed, with costs, and tbe cause remanded for further proceedings not inconsistent with this opinion. Reversed and remanded.