The price to be paid must be certain, or so referred to a definite standard that it may be made certain; (p)1 as what another * man has given; or what another man shall say should be the price; but if this third party refuse to fix the price, the sale is void. (q) And the thing sold must be specific, and capable of certain identification. There must be an agreement of mind as to this; and if there be an honest error as to the price, or as to the substantial and essential qualities of the thing sold (not as to its mere worth or condition), the sale may be treated as null; (r) but this perhaps should be confined to cases where the difference between the thing bought and the thing supposed to be bought, is sufficient to affect its identity. For anything less than this the parties must be left to the law of warranty. (s) This agreement of mind may be expressed orally or by letter; but we have already considered these questions fully, when treating of assent; and we would refer in this connection to what we there said, (t) adding here, that where a proposal to purchase goods is made by letter sent to another State, and is there assented to, the contract of sale is made in that State, and if it is valid by the laws of the latter State, it will be enforced in the State whence the letter is sent, although it would have been invalid if made there. (u)

(o) Bradford v. Tappan, 11 Pick. 76, 79.

(p) Brown v. Bellows, 4 Pick. 189, where the price was fixed by referees, and the court said in giving judgment: " It is objected that the price should have been fixed by the agreement, whereas it was to be ascertained by the referees; and we are referred to Inst. 3, 24, pr. where it is said: 'Pretium autem constitui oportet, nam nulla emptio sine pretio esse potest.' But we apply another rule - id certum est, quod certum reddi potest It was, indeed, formerly doubted whether, when a thing was to be sold, at whatever price Titius should value it, such contract would be good; but by Inst. 3, 24, 1, it is decided that it would be 'sed nostra decisio ita hoc constituit, ut quoties sic composita sit venditio, quanti ille aestimaverit, sub hac conditione staret contractus, ut siquidem ille, qui nominatus est, pretium definierit tunc omnimodo secundum ejus aestimationem et pretium persolvatur, et res tradatur, et venditio ad effectum perducatur.' So it is said in Ayliffe, Civ. Law, b. 4, tit. 4: 'The price agreed on between the parties ought to be certain; wherefore a purchase is not valid if it depends on the will of the buyer or seller; though such price may be well enough referred to the arbitration of a third person to adjudge and determine the value of the thing sold.' ' And thus the certainty of a price may be had, either by the determination of the contracting parties themselves, or else by relation had to some person or thing.' In the case at bar, the referees have fixed the price, and according to these authorities, and the reason of the thing, the sale should be carried into effect, unless for some other objection which has been made by the counsel for the defendant, it should be differently determined." See also Flagg v Mann, 2 Sumner, 539: Cunningham v. Ashbrook, 20 Mo. 553; McCandlish v. Newman, 22 Penn. St. 460.

(q) Story on Sales, § 220. A sale may be made of an article for what it is worth, for that can be ascertained by experts. See Hoodley v. McLaine, 10 Bing. 487; Acebal v. Levy, id. 382. See also Dick-son v. Jordan, 12 Ired. L. 79, and 11 Ired. L. 166.

1 If not fixed, a reasonable price is implied, James v. Muir, 33 Mich. 223, 227; as the market price at the time and place of delivery. McEwen v. Morey, 60 Ill. 32. See Callaghan v. Myers, 89 Ill. 566. The price may be fixed by valuers, Newlan v. Dunham, 60 Ill. 233; but if they refuse to act, there is no contract in the case of an executory sale. Wittkowsky v. Wasson, 71 N. C. 451. If by a referee, there is no sale until he fixes the price. Hutton v. Moore, 26 Ark. 382; Vickers v. Vickers, L. It. 4 Eq. 529. See Brown v. Cole, 45 Ia. 601. Where the price of wheat was to be fixed by the seller by a certain standard, and it was destroyed before so fixed, it was held to be the buyer's loss. McConnell v. Hughes, 29 Wis. 537; Easterlin v Rylander, 59 Ga. 292; Ames v. Quimby, 96 U. S. 324. - K.