This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
In most of the cases in which impossibility of performance is relied upon as a discharge, the impossibility has gone to the entire performance of the contract.1 Cases are, however, presented in which the impossibility of performance goes to part of the contract only. This impossibility may involve alternative covenants, which have been discussed elsewhere,2 or it may involve conjunctive covenants. In the latter case, the same principles seem to apply to impossibility as apply to breach of one of a number of distinct covenants.3 If the contract is entire, the question to be determined is whether the covenant which has become impossible of performance is a vital covenant or is merely a subsidiary provision. If the covenant is a vital covenant, subsequent impossibility of performance of such covenant operates as a discharge of the entire contract.4 The federal employers' liability act, which renders invalid a covenant in a contract between an employe and a railway whereby the employe agrees that if he accepts relief from the relief department he waives his claim for damages, renders invalid the remaining covenants of such contract and prevents the employe from asserting any claim against the relief department of such railway.5 This result was reached, however, in a case in which the employe had sued the railway for his injuries and had recovered damages; and he was now attempting to recover from the relief department of such railway in addition to his recovery in a tort action.6 If a contract by which A is to collect B's accounts provides for the use of B's system of advertising judgments against delinquent debtors, and such method of collecting accounts is subsequently made illegal, such impossibility operates as a discharge of the entire contract.7
1 Davidson v. Gaskill, 32 Okla. 40, 38 L. R. A. (N.S.) 692, 121 Pac. 640.
2 Davidson v. Gaskill, 32 Okla. 40, 38 L. R. A. (N.S.) 692, 121 Pac. 649.
3 Davidson v. Gaskill, 32 Okla. 40, 38 L. R. A. (N.S.) 692, 121 Pac. 649.
4 See Sec. 2717.
5 Prince v. Haworth  2K.B. 768.
1 See Sec. 2681 et seq.
2 See Sec. 2708.
3 See ch. LXXXIV.
4 Baltimore & O. R. Co. v. Miller, 183 Ind. 323, 107 N. E. 545; American Mercantile Exchange v. Blunt, 102 Me. 128, 120 Am. St. Rep. 464, 10 L. R. A. (N.3.) 414, 66 Atl 212.
If, on the other hand, the covenant which has become impossible is a minor and subsidiary covenant, impossibility of performing such covenant does not discharge the entire contract.8 A contract by which A is to remove rock from B's land, and to crush it, and B is to permit A to make use of B's premises for such purposes, is not discharged by the fact that A is enjoined from crushing rock upon such premises, since the place of performance is not of the essence of the contract.9 A contract of fidelity insurance is not discharged by the death of the employe whose fidelity is insured during the time for which such insurance is to run, so as to permit a recovery of the unearned amount of the premium, at least if the great bulk of the risks to secure which such insurance was given, have been accounted for during the lifetime of such employe.10 A lease which passes an interest in certain realty is not discharged by the destruction of the buildings thereon.11 A lease of premises for a number of purposes, including their use as a saloon, is not discharged by the fact that the use of such premises for use as a saloon is prevented by subsequent legislation or competent political authority.11 If a carrier has agreed to transport a passenger to a specific place, and from that place to another by a specific steamer, the identity of the steamer is not so vital an element of the contract that, on its destruction, the carrier can abandon the passenger at a point far from his own home. On the contrary, the carrier must, at least, use due diligence to furnish other means of transportation to him.13
5 Baltimore & O. R. Co. v. Miller, 183 Ind. 323, 107 N. E. 545.
6 Baltimore & O. R. Co. v. Miller, 1S3 Ind. 323, 107 X. E. 545.
7 American Mercantile Exchange v. Blunt, 102 Me. 128, 120 Am. St. Rep. 404, 10 L. R. A. (N.S.) 414, 06 Atl. 212.
8 Standard Brewing Co. v. Weil, 129 Md. 487, L. R. A. 1917C, 929, 99 Atl. 661; Williams v. Vanderbilt, 28 N. Y. 217, 84 Am. Dec. 333; Crouch v. Southern Surety Co., 131 Tenn. 260, L. R. A. 1915D, 966, 174 S. W. 1116; Brown v. Ehlinger, 90 Wash. 585, 156 Pac. 544.
9 Brown v. Ehlinger, 90 Wash. 585, 156 Pac. 544.
10 Crouch v. Southern Surety Co., 131 Tenn. 200, L. R. A. 1915D, 966, 174 S. S.W 1116.
11 England. Hare v. Grovos, 3 Anstr. 687.
Massachusetts. Ware v. Hobbs, 222 Mass. 327, 1 110 N. E. 903.
Michigan. Bowen v. Clemens, 161 Mich. 493, 126 N. W. 639.
Ohio. Linn v. Ross, 10 Ohio 412, 30 Am. Dec. 95.
Oregon. Moline v. Portland Brewing Co., 73 Or. 532, 144 Pac. 572.
See, Destruction of Demised Building, by J. E. Hogg, 26 Law Quarterly Review 71.
If the party who is prejudiced by the destruction of part of the subject-matter is willing to perform regardless of the fact of such destruction, the party not prejudiced thereby can not invoke such fact as a discharge.14 Thus destruction of buildings upon certain land after a contract for the sale thereof does not discharge the contract if the vendee is willing to carry out the contract as if the buildings were still standing.15 A contract to remodel a building using old walls was partly performed when the walls fell. The owner restored the building to the condition in which it was just before the accident, and demanded that the contractor complete it. Such facts were held not to discharge the contractor.16
If the party who is prejudiced by the partial injury on destruction demands performance with compensation for actual damage, it has been held that the adversary party can not treat the contract as discharged.17
If the covenant, the performance of which has become impossible, is an independent covenant, the impossibility of such performance does not operate as a discharge of the remaining covenants.18 If A entered into a contract by which he agreed to furnish seed potatoes to B at a specified price, and it was further agreed that if A demanded B's crop at a price of fifty cents per bushel above the market price, B should deliver his entire crop to A and should pay an additional amount per bushel for such seed, and A demands delivery of such crop after it has been destroyed without B's fault, it has been held that the destruction of the crop does not discharge B's covenant to pay such additional amount for the seed, since the two covenants are independent and since the covenant to pay such additional amount has not become impossible.19
12 Standard Brewing Co. v. Weil, 129 Md. 487, L. R. A. 1917C, 929, 99 Atl. 661.
13 Williams v. Vanderbilt, 28 X. Y. 217, 84 Am. Dec. 333.
14 Hallett v. Parker, 68 N. H. 598, 39 Atl. 433.
15 Hallett v. Parker, 68 N. H. 598, 39 Atl. 433.
16 Chapman v. Beltz, 48 W. Va. 1, 35 S. E. 1013.
In some cases this is regarded as requiring performance different from that agreed upon. See Sec. 2693.
17 Cunningham Iron Co. v. Warren Mfg. Co., 80 Fed. 878.
18 Varney v. Cole, 114 Me. 329, 96 Atl. 232.