But, in the two former cases, neither of the Contracting parties can by any means at his own option recede from the Agreement, unless for some just and reasonable cause; as, if the terms of the contract were, that either of the parties may with impunity retract within a certain period; then, indeed, either party may within the period prescribed avail himself of the terms of the Contract and recede, without being liable to any penalty: since it is, generally speaking, unquestionable that, _Conventio legem vincit_.[397] Besides, if the Vendor sold the thing to the Purchaser as being sound and without fault,[398] and the Purchaser can afterwards satisfactorily shew, that the thing at the time of the contract was not sound, but faulty, then, indeed, the Vendor shall be compelled to take back his property. But it is sufficient, if the thing was in a proper state, at the time of the Contract, whatever may afterwards happen to it. But I doubt, as to the period within which this should be proved, or complaint made concerning it, especially where there is no special Agreement. Where, however, Earnest only has been given, if the Purchaser would recede from the Contract, he may do so, with the loss of the Earnest. But if, in such case, the Vendor would retract, it is a question whether he can do so without incurring a penalty.[399] It does not seem that he can; because he would then be in a better situation than the Purchaser. But, if it cannot be done with impunity, what punishment shall such conduct incur?[400] The risk of the thing sold and purchased generally belongs to the person who has possession of it,[401] unless it has been differently arranged. [Footnote 397: _Pactum enim legem vincit._ (LL. Hen. 1. c. 49.) “Contracts legally made have the force of Law between those who have made them.” (Code Napoleon s. 1134.)] [Footnote 398: If, says a Law of Ina, a person has purchased any thing, and, within thirty days, discover it to be defective, he may restore the thing to the hands of the Vendor, unless the latter will swear, that he knew of no defect in it at the time he sold it. (LL. Inæ. c. 56.)] [Footnote 399: In Bracton’s time the Vendor forfeited double the Earnest—a rule according with that of the Roman code. (Bracton 62. a.)] [Footnote 400: “_Double the Earnest_” was to be forfeited by him according to the Reg. Maj. (L. 3. c. 10.)] [Footnote 401: _Quia re vera qui rem emptori nondum tradidit adhuc ipse dominus erit._ Hence—_Si post emptionem ante traditionem fundo vendito aliquid per alluvionem vel alio modo accrevit quod commodum ad venditorem pertinebit._ (Bracton 62. a.)] CHAP. XV. The Vendor and his Heirs are bound to warrant the thing sold to the purchaser and his Heirs, if the thing be an immoveable; and hence, the Purchaser[402] and his Heirs may be sued in the manner we have formerly explained, in treating of Warranties.