The opinion was delivered at March term 1855.

The bill in equity in this case seeks to obtain from the defendant the conveyance of a piece of land in Chelsea, which the plaintiff claims under the following contract: “ Boston, January 28th 1851. In consideration of fifty dollars, I agree to convey to G. W. Gerrish, the wharf and flats occupied by Towne & Hardin, and owned by Francis Head, any time within thirty days from date, on the payment of eight thousand dollars in cash, the premises to be free from all incumbrance. Luther Towne.”

The bill is framed with a double aspect, and alleges the right of the plaintiff to the conveyance which he seeks, on two grounds. The first is, that, by the terms of the contract itself, the defendant is bound to convey the property in question, and that a court of equity will decree its specific performance. The second is, that, by reason of a confidential relation of agency or brokerage subsisting between the parties, and the payment of the plaintiff’s money for the lot of land in question, a resulting trust is created in favor of the plaintiff, which the court will enforce by a decree for the conveyance of the property by the defendant to the plaintiff. An objection was taken to the form of the bill, on the ground that it was inconsistent in its allegations, and if maintained at all, could not be supported as a bill for specific performance. But upon looking at the bill, we think it sufficiently sets out in its stating part a contract on the part of the defendant for the conveyance of property, which it prays to have performed. It is true that it also alleges an agreement between the parties, and acts done in pursuance of if by which a trust is sought to be established, under which the plaintiff claims a conveyance of the same estate. This is entirely consistent with the established rules of equity pleading A party may well frame his bill in an alternative form, and aver facts of a different nature in its support. If the title to relief *87will be the same in either alternative, the bill can be maintained, although the case is presented upon allegations resting on en tiiely distinct and independent grounds. Story Eq. PL § 254. 1 Dan. Ch. Pract. 395.

The right of the plaintiff to the specific performance which he seeks in the present case depends upon the true construction of the contract between the parties. The plaintiff contends that i! the wharf and flats occupied by Towne & Hardin, and owned by Francis Head,” include a parcel of land lying north-of Marginal Street, and separated by said street from the property already conveyed to the plaintiff by the defendant. The defendant, on the other hand, alleges that by the conveyance executed and delivered by him to the plaintiff, of the estate lying South of Marginal Street, he has fully complied with the terms of the contract; and that the lot of land lying north of said street is not included in the description of the estate which he agreed to convey to the plaintiff.

It is quite obvious that the issue thus made between the parties cannot be determined by reference solely to the terms of the written contract. These are sufficiently intelligible, and by themselves present no patent ambiguity. If any doubt exists in respect to them, it arises from extrinsic facts, and creates a case of latent ambiguity which renders paroi evidence admissible to aid in its construction. The rule of law applicable to cases of this kind is very familiar. Whenever, in a contract or conveyance, an estate is specifically and fully described by monuments, bounds and admeasurements, no evidence dehors the writing can be admitted to show the intention of the parties in making the contract or conveyance, or to prove what estate is comprehended by the written description. But where general terms oi ly are used to designate the subject matter of the agreement oi conveyance, or the description is of a nature to call for evidence to ascertain the relative situation, nature and qualities of the estate, then paroi evidence is not only admissible, but is absolutely essential to ascertain the true meaning of the instrument, and to determine its proper application with reference to extrinsic circumstances and objects. In such cases paroi evi*88dence is not used to vary, contradict or control the written contract of the parties, but to apply it to the subject matter, and thereby to render certain what would otherwise be doubtful and indefinite. For this reason, any evidence which tends to indicate the nature of the subject matter included in a written contract, which would otherwise be uncertain or ambiguous, and to determine its application relatively to other objects, is admissible, as affording just means of interpretation of the intention of the parties. In the application of this general rule, it has therefore been held competent for parties to a written contract to show in aid of its interpretation the position of land and its condition, the mode of its use and occupation, that it had acquired a local designation or name by which it was known and distinguished, and also to show whether it was parcel of a particular estate. 1 Greenl. Ev. §§ 286, 288. Smith v. Jersey, 2 Brod. & Bing. 553. Paddock v. Fradley, 1 Cr. & J. 90. Murly v. M'Dermott, 8 Ad. & El. 138. Waterman v. Johnson, 13 Pick. 261. Brown v. Thorndike, 15 Pick. 400. Sargent v. Adams, ante, 79. By the terms of the contract in question, it is clear that the land included in the written contract can be ascertained only by resort to extrinsic facts. “ The wharf and flats occupied by Towne & Hardin, and owned by Francis Head,” is a general description referring to extrinsic objects and circumstances, which renders it necessary to resort to paroi evidence to prove the existence of the facts by which alone this description can be applied to its subject matter.

This rule of evidence is not disputed by the counsel for the defendant, but it is urged that it has no application to the case at bar. It is not denied that if the question at issue was solely as to the lot of land lying below Marginal Street, it would be competent for the plaintiff to show by paroi proof what were the wharf and flats occupied by Towne & Hardin, because these words, taken in their strict primary sense, are sensible with reference to extrinsic circumstances, and are directly applicable in all respects to that parcel of land; But it is argued that it would tend directly to vary and control the written contract, to admit evidence^ to show that the piece of land lying north of Marginal *89Street was included in these terms of description, because it would prove that the words were used in an unusual and secondary sense, so as to include a separate tract of upland which can in no proper sense be described as wharf and flats. This position would be decisive of the question if it were supported by the facts in proof. It is true that the two pieces of land are now separated by a street, and that the upper parcel, which is the subject of controversy, is thereby cut off from immediate access to the water, so that vessels cannot be unloaded directly upon it. But it is also true that it is proved by the testimony in the cause that prior to 1836 or 1837, when Marginal Street was built, the two pieces constituted one entire parcel of land; that they have for many years been used together; and that, before the street was built, the whole of the upper parcel above the street was covered with water at very high tides, and a part of it was so covered at all ordinary tides; that both parcels have been filled up, and for many years have been occupied for the purpose of receiving wood and lumber from vessels, and storing it for sale. Upon this state of facts, we think the paroi evidence does not prove that the words “ wharf and flats,” in order to be applicable to the upper lot, must be used in any unusual or secondary sense; but that it tends to show that they were primarily sensible with reference to the upper as well as to the lower parcel. For these reasons, we are of opinion that the paroi evidence offered by the plaintiff was competent and admissible for the purpose of showing that the upper lot was intended by the parties to be included in the term “ wharf and flats” used in the written contract.

The question still remains as to the effect of the evidence offered by the plaintiff to show that the upper lot was comprehended in the description of the land which the defendant agreed to convey to him. Upon a careful scrutiny of the testimony, and laying aside that portion of the evidence which was given by the near relatives of the plaintiff, we think it is satisfactorily proved, in addition to the facts already enumerated, that both parcels of land, having long been used and occupied together for the landing of wood and lumber, and its storage and sale, *90were foi many years generally known as and called in the vicinity “ Towne & Hardin’s wharf;” that they were so designated by the defendant and his copartner; and that the wood and lumber lying thereon had been insured by the defendant, and described in the policy as being on Towne & Hardin’s wharf. Besides, and this perhaps is the most significant evidence, it appears by the testimony of Head, the original owner of the estate, that in the agreement which he gave to the defendant in the winter of 1851 for the conveyance of these premises, in pursuance of' which the entire estate was conveyed to the defendant in February following, the same words “ wharf and flats ” were used to designate both parcels. This fact far outweighs any inference which can be drawn from the leases made by Kuhn to the defendant and his copartner in the years 1843 and 1845, in which the premises are described separately, the lower lot as wharf and flats, and the upper parcel as a piece of land. It shows the understanding of the defendant as to the meaning of these words at the time when the written agreement was given by him to the plaintiff, and that they were then used to designate both parcels. That such was the full understanding between the parties is also shown by the studious care with which the defendant kept from the plaintiff’s knowledge the fact that the upper parcel had been conveyed to him by Head by a separate deed, on the same day as that on which the deed of the lower lot was executed, and his subsequent representation, as testified to by Hubbard, that he was unable to procure a deed of the upper lot for the plaintiff, but that it was a gift to him from Head. We cannot think any great weight is to be attached to the fact that the defendant gave to the plaintiff a warranty deed of the lower lot, of which he had only taken a deed of release and quitclaim from Head. It does not appear that there was any doubt concerning the title, or that any importance was attached to the form of the deed, at the time, by the plaintiff or defendant.

It was urged by the defendant, that the acceptance by the plaintiff of the deed of the lower lot, with a full knowledge that it conveyed only that lot, was not only conclusive evidence-of his understanding of the terms used in the contract, but *91estopped him from setting up any claim under it to a conveyanóe of the upper parcel. This would be a sound, and perhaps a conclusive answer to the plaintiff’s case, if we were not satisfied that the plaintiff received the deed under a misapprehension, induced by the statements of the defendant that he had been unable to procure a conveyance of the upper lot. This appears from the evidence of Hubbard, an impartial and disinterested witness, who in this particular corroborates fully the evidence of Benjamin T. Gerrish, the plaintiff’s brother. The plaintiff, having acted under a mistake of facts caused by the misrepresentations of the defendant, in taking the deed of the lower lot, cannot be held to have waived any of his legal rights, or to be estopped from enforcing them as against the defendant.

Without going more at large into the case, it is sufficient to say that, for the reasons already given, we are of opinion that the' paroi evidence was competent and admissible for the purpose of enabling the court to apply the terms of the written contract to the subject matter; that upon this evidence we are satisfied that both parcels were included within the term “ wharf and flats,” and that the original intention of both parties was to embrace both parcels in the agreement for a conveyance; that the defendant is not estopped by any act of his from claiming a full performance of the agreement from the defendant, and is en-titled to a decree for a conveyance of the upper lot, as prayed for in his bill. It therefore becomes unnecessary to express any opinion upon the other branch of the case.

One question of practice was raised in the argument, upon which it may be well to express an opinion. The plaintiff in his bill waived the oath of the defendant to the answer. The defendant, notwithstanding this express waiver, answered under oath. The plaintiff, without moving the court for the cancellation of the oath, filed a general replication. A general replication waives all insufficiencies and defects in the answer; but it does not at all affect the question of its competency as proof of the facts and statements which it contains. Such indeed is the necessary effect of the rule itself, which provides that when the *92plaintiff waives the necessity of the answer being made on the oath of the defendant, “ the answer may be made without oath, and shall have no other or greater force as evidence than the bill.” Fifth rule in chancery of this court, 24 Pick. 41L

Specific performance decreed.