in England, than that in sales of personal property, in the absence of express warranty, where the buyer has an opportunity to inspect the commodity, and the seller is guilty of no fraud, and is neither the manufacturer nor grower of the article he sells, the maxim of caveat emptor applies. Such a rule, requir ing the purchaser to take care of his own interest, has been found best adapted to the wants of trade in the business transactions of life. And there is no hardship in it, because, if the purchaser distrusts his judgment, he can require of the seller a warranty."

§ 834. How in sales of patents. This question has arisen frequently in actions brought to recover upon notes or other obligations given upon the sale or assignment of patents for inventions which have subsequently proven to be of little or no value. In such cases it is well settled that if the patent prove to be void, either because the alleged invention was not new or was not useful or because of defects in the issue of the patent, the note or other promise to pay is without consideration, and the money, if paid, can be recovered,' or, if not paid, no action can be maintained, even though the seller acted in good faith and both parties supposed the patent to be valid.

1 Sandage v. Studabaker Bros. Mfg. Co. (1895), 142 Ind. 148, 41 N. E. R. 380, 51 Am. St. R. 165.

2 In Nash v. Lull (1869), 102 Mass. 60, 3 Am. R. 435, Gray, J., said: "Letters patent of the United States can be lawfully granted only for new and useful inventions; and are but prima facie evidence of the novelty and utility of the invention described. U. S. Stat. 1837, ch. 45; Corning v. Burden, 15 How. (U. S.) 270, 271. All that is required to make an invention useful, under the patent laws, is that it should be capable of being applied to some practical and beneficial purpose, and not to be frivolous or injurious to the well being or morals of society. If it is useful in

this sense, it is patentable, and the degree of its utility or practical value does not affect the validity of the patent; if it is not useful, a patent for it is void. Lowell v. Lewis, 1 Mason, 185, 186; Bedford v. Hunt, id. 303, 304; Kneass v. Schuylkill Bank, 4 Wash. C. C. 12; Langdon v. De Groot, 1 Paine, 203; Roberts v. Ward, 4 McLean, 565. In a suit brought on a promissory note, the only consideration for which is the assignment of an interest in or right under a patent, the question of consideration depends upon the validity of the patent; if the patent is void, the note is of course without consideration; but if it is valid, the court will not inquire into the adequacy of the con

[$ 835. But if the patent is valid there may be a recovery notwithstanding the invention proves to be of little value, for the court will not inquire into the adequacy of the consideration.1

This rule is based, not upon the ground of implied warranty of validity for it is held that no such warranty is implied,but upon the ground of a failure of the consideration.2

3

835. How in sales of commercial instruments.-The same kind of question is sometimes raised in actions upon promises to pay for notes, bonds, scrip and other commercial paper which has proven not to be genuine. There is here a failure of consideration which will constitute a defense; but the law sideration. The issue in such a case (Tenn.) 418; Myers v. Turner (1855), is, therefore, the same as in a suit in 17 Ill. 179, and other cases supra. the courts of the United States for the infringement of a patent, the validity of which is denied by the defendant; and so it has been repeatedly adjudged in this and other courts. Bliss v. Negus, 8 Mass. 46; Dickinson v. Hall, 14 Pick. 217, 25 Am. Dec. 390; Bierce v. Stocking, 11 Gray, 174; Lester v. Palmer, 4 Allen, 145; Dunbar v. Marden, 13 N. H. 311; Cross v. Huntly, 13 Wend. (N. Y.) 385; Geiger v. Cook, 3 W. & S. (Pa.) 266; McClure v. Jeffrey, 8 Ind. 79; Myers v. Turner, 17 Ill. 179; Jolliffe v. Collins, 21 Mo. 338." Clough v. Patrick, 37 Vt. 421, was distinguished, and Elmer v. Pennel, 40 Me. 430, was denied. To the like effect, that a promise to pay for a void patent is without consideration, see Harlow v. Putnam (1878), 124 Mass. 553; Jack son v. Allen, 120 Mass. 64; Shepherd v. Jenkins (1881), 73 Mo. 510; Cowan v. Dodd (1866), 3 Coldw. (Tenn.) 278; Bellas v. Hays (1819), 5 S. & R. (Pa.) 427, 9 Am. Dec. 385; Keith v. Hobbs (1878), 69 Mo. 84; Rowe v. Blanchard (1864), 18 Wis. 441; National Bank v. Peck (1871), 8 Kan. 660. See also McKee v. Eaton (1881), 26 Kan. 226.

1 Green v. Stuart (1874), 7 Baxt.

An English patent, if regular in form and in existence as a document, is, by force of the English decisions (see Hall v. Conder, 2 C. B. (N. S.) 22, 53; Noton v. Brooks, 7 Hurl. & N. 499; Trotman v. Wood, 16 C. B. (N. S.) 479; Adie v. Clark, L. R. 3 Ch. Div. 134; Lawes v. Purser, 6 El. & Bl. 930; Smith v. Neale, 2 C. B. (N. S.) 67; Bowman v. Taylor, 2 Ad. & El. 278; Hills v. Laming, 9 Exch. 256; Wiles v. Woodward, 5 id. 557; Cutler v. Bower, 11 Ad. & El. (N. S.) 973), sufficient con. sideration to support a promissory note made in Massachusetts, even though the patent is in fact invalid for want of novelty, and notwithstanding the fact that under the Massachusetts decisions a note given for an invalid United States patent is without consideration. Chemical Electric Co. v. Howard (1889), 148 Mass. 352, 2 L. R. A. 168, 20 N. E. R. 92. 2 Hiatt v. Twomey (1836), 1 Dev. & Bat. (N. C.) Eq. 315; 3 Robinson on Patents, §§ 1230-1239, where this subject is more fully discussed.

3 Wood v. Sheldon (1880), 42 N. J. L 421, 36 Am. R. 523; Thrall v. Newell (1847), 19 Vt. 202, 47 Am. Dec. 682; Aldrich v. Jackson (1858), 5 R. L. 218.

also implies a warranty in such cases, and the subject is reserved for fuller consideration when the subject of implied warranties is reached.1

§ 836. How on sale of goods to which seller had no title.A similar question arises also where the purchaser has been divested of the goods by a title superior to that of his vendor, or where the goods have been taken from him as the goods of the vendor upon some claim or process to which the attempted sale must have been subject. Here also is an unquestionable failure of consideration, which will defeat a recovery. There is also, usually, as will be seen, an implied warranty of title, and the whole question will be considered later.3

§ 837. How in case goods sold conditionally are retaken by the seller.- The defense of a failure of consideration has likewise been interposed in actions brought upon promises to pay for goods which have been delivered upon a contract of purchase or a conditional sale, and which have been subsequently retaken by the vendor. In such cases it has been held by some courts that, upon such retaking, the promise to pay for the goods fails, and that therefore no recovery can be had." The true defense, however, is undoubtedly that considered in an earlier action, namely, that the retaking must have been a rescission of the contract which releases both parties.5

II.

As GROUND OF ACTION By Buyer.

§ 838. Buyer may have action to recover price paid without consideration. The objection of a want or failure of conCompare Christy v. Sullivan (1875), 50 Cal. 337, 19 Am. R. 655.

1 See post, § 1332.

2 Matheny v. Mason (1881), 73 Mo. 677, 39 Am. R. 541; Bailey v. Foster (1829), 9 Pick. (Mass.) 139; Dyer v. Homer (1839), 22 Pick. (Mass.) 253; Hunt v. Sackett (1875), 31 Mich. 18; Costigan v. Hawkins (1867), 22 Wis. 74; Marshall v. Duke (1875), 51 Ind. 62.

3 See post, § 1300.

4 Minneapolis Harvester Works v. Hally (1881), 27 Minn. 495, 8 N. W. R. 597 (but see, as to this, Aultman v. Olson, 43 Minn. 409, 45 N. W. R. 852); Howe Machine Co. v. Willie (1877), 85 Ill. 333. See also ante, § 620, where the cases are more fully collected. 5 See ante, § 617.

sideration may also to anticipate somewhat matters more fully considered in a later chapter-furnish the foundation for an action by the buyer to recover the price paid. Thus, for example, if the buyer has paid the price, but the title has failed and he has been divested by the true owner; or if he has paid for a patent which proves to be invalid;2 or if he has paid for commercial instruments, such as notes, bonds, scrip, and the like, which prove not to be genuine,'-in these and the like cases he may recover his money as paid without consideration.

§ 839.. So, if the buyer has paid the price in advance, but has never received the goods at all; or has rejected them wholly, as he had the right to do because they were not such as the contract contemplated; or if they were not as agreed, but entirely worthless; or if the agreed article has not been delivered, but another substituted for it, and the latter has been returned, in these and similar cases there is a total failure of consideration, and the buyer may recover his money. He may likewise do so pro tanto where he has paid for more than he has received.8

1 Eicholtz v. Bannister (1864), 17 Com. B. (N. S.) 708; Ledwich v. McKim (1873), 53 N. Y. 307; Wilkinson v. Ferree (1855), 24 Pa. St. 190.

2 Darst v. Brockway (1842), 11 Ohio, 462.

3 Frank v. Lanier (1883), 91 N. Y. 112; Wood v. Sheldon (1880), 42 N. J. L. 421, 36 Am. R. 523; Thompson v. McCullough (1860), 31 Mo. 224, 77 Am. Dec. 644; Gurney v. Womersley (1854), 4 El. & Bl. 133, 82 Eng. Com. L. 132; Paul v. Kenosha (1867), 22 Wis. 256, 94 Am. Dec. 598; Terry v. Bissell (1857), 26 Conn. 23.

4 Nash v. Towne (1866), 72 U. S. (5 Wall.) 689; Dalton v. Bentley (1854), 15 Ill. 420; Cleveland v. Sterrett (1871), 70 Pa. St. 204.

Pope v. Allis (1885), 115 U. S. 363; Meader v. Cornell (1895), 58 N. J. L. 375, 33 Atl. R. 960.

6 Petersen v. Door, Sash & Lumber Co. (1883), 51 Mich. 86, 16 N. W. R. 243; Ripley v. Case (1889), 78 Mich. 126, 43 N. W. R. 1097, 18 Am. St. R. 428.

The consideration fails entirely where the seller of trees agrees to set them out and care for them, but neglects to do so, whereby they become totally worthless. Perkins v. Brown (1897), 115 Mich. 41, 72 N. W. R. 1095.

7 Howe Machine Co. v. Willie (1877), 85 Ill. 333.

8 Devaux v. Conolly (1849), 8 C. B. 640, 65 Eng. Com. L. 639; Wheadon v. Olds (1838), 20 Wend. (N. Y.) 174; Hill v. Rewee (1846), 11 Metc. (Mass.) 268; Devine v. Edwards (1877), 87 Ill. 177; (1881) 101 Ill. 138.

§ 840. Purpose of this chapter.-In a preceding chapter there has been given quite a full consideration of the question of the mistakes which will prevent the creation of the contract in the first instance, but some reference to the same general subject seems desirable in this place as furnishing another of the grounds which will justify the avoidance of the assumed

contract.

§ 841. Kinds of mistake involved. As seen in the previ ous discussion, the kinds of mistake which most frequently affect the formation of the contract are: mistake as to the nature of the transaction, mistake as to the identity of the parties, mistake regarding the existence, identity, quantity, kind, quality, character or location of the thing sold, mistake respecting the terms of the contract, and mistake as to the possibility of performance.

§ 842. Mistake which would prevent formation will justify avoidance of contract.-It must in general be true that

1 See ante, § 265-279.