§ 994. There can be no sale without a price. Sine pretio nulla venditio est.1 Unless there be a valuable consideration, it is a gift. So, also, the price must be in money, or in its negotiable representative, - as notes or bills; for if articles be given one for another, it is merely a barter. The same principles of law, however, govern in cases of barter and of sale. The price must be a sum of money, either certain and definite, or susceptible of ascertainment by reference to some criterion prescribed in the contract,2 so as to render further negotiation between the parties unnecessary.8 Thus, a reference to a certain sum given by another person, or to the arbitration of a third person, is sufficient.4 Mere inadequacy of price, however, affords no ground to set aside a sale, unless it be of so gross a nature as to afford a necessary presumption of fraud and imposition, and then a court of equity will grant relief.5

1 Dig. Lib. 18, tit. 1, 1. 2; Instit. Lib. 3, tit. 24; Pothier, Contrat de Vente, art. 11, n. 16, 17, 18, etc.

2 See Dickson v. Jordan, 12 Ire. 79.

3 Flagg v. Mann, 2 Sumner, 486, 539; 2 Kent, Comm. 477; Long on Sales, 5; 1 Bell, Comm. 437; Brown on Sales, 148; Brown v. Bellows, 4 Pick. 179, 189; Pothier, Contrat de Vente, No. 23, 24.

4 1 Stair, Inst. B. 1, tit. 14; Brown v. Bellows, 4 Pick. 179, 189.

5 The rule in the civil law was, that a sale for one-half the value of the property might be set aside for inadequacy. 1 Doinat, Civ. Law, B. 1, tit. 2, § 3, 9, art. 1; Heinnec. Elem. Jur. 1 N. &. G. § 352; Ibid. § 316; Cod. Lib. 4, tit. 44, 1. 2, 9; Pothier on Oblig. by Evans, § 30, 33, 34; Osgood v. Franklin, 2 Johns. Ch. 1, 23, 24; Copis v. Middleton, 2 Madd. 410; Griffith v. Spratley, 1 Cox, 383; Butler v. Haskell, 4 Desaus. 651; Nott v. Hill, 1 Vern. 167; 2 Vern. 27; Story on Eq. Jur. § 244, 245, and cases cited; Robinson v. Schly & Cooper, 6 Ga. 515; Bedel v. Loo-mis, 11 N. H. 9.