Sec. 109. In general.
Sec. 110. Non-enforceability may result from prevention: (1) of plaintiff's performance, or (2) of defendant's performance.
Sec. 111. (I) Plaintiff's performance prevented : In general.
Sec. 113. Same : Presumption rebuttable.
Sec. 114. Same : Effect of express stipulation.
Sec. 115. (2) Receipt of benefit by defendant.
Sec. 116. (a) Destruction of building in course of improvement.
Sec. 117. Same : Upon principle.
Sec. 118. Same : Doctrine of Niblo v. Binsse.
Sec. 119. (b) Destruction of personalty in course of alteration or repair.
Sec. 120. (c) Loss of goods in course of carriage: Disablement of carrying vessel.
Sec. 121. (d) Loss of vessel in course of seaman's service.
Sec. 122. (e) Illness or death of contractor.
Sec. 123. Same : Limitation of rule.
Sec. 124. (/) Act of government.
Sec. 125. (3) Measure of recovery.
Sec. 126. Same : In case of insurance contracts.
Sec. 127. (II) Defendant's performance prevented : In general.
Sec. 128. (1) Recovery of prepaid purchase price of goods or land.
Sec. 129. (2) Recovery of prepaid freight.
Sec. 130. (3) Enforcement of restitution impracticable : Part payment of unapportionable consideration.
Sec. 131. (4) Enforcement of restitution inequitable: Change of position.
Strictly speaking, a contract is not discharged by reason of being or becoming impossible of performance. But not infrequently a contract which in terms is unconditional is in substance and effect subject to a condition which protects the contractor against a contingency which makes performance impossible.1 In other words, the contract is so construed, by reading an implied condition into it, as to excuse the contractor from his obligation under the particular circumstances which make performance impossible. The scope of this chapter is confined to cases in which a benefit is conferred in reliance upon a contract the failure to perform which is so excused.