The delivery of goods that may be accurately designated by number, weight or measure, such as corn or wine, on an undertaking that goods of like kind and quality shall be returned, creates what is known in the civil law as the contract of mutuum, a kind of bailment contract. Text writers on the common law regard such a transaction as a sale and not a bailment. "Where there is no obligation to return the specific article, and the receiver is at liberty to return another thing of equal value, he becomes debtor to make the return, and the title in the property is changed-the transaction is a sale." Benjamin on Sales, p. 5, n. 1. In such a case if the property delivered "is lost or destroyed by accident, it is the loss of the borrower, for it is his property." Story on Bailments §283; Schouler on Bailments p. 5. These propositions have long been elementary, but the courts have experienced much difficulty in applying them; and it may be said, that in view of recent decisions, the propositions are too broadly stated. Many cases have come before the courts wherein the contracts between the parties called for the return of other property than that delivered, but of like kind and value, which have been regarded as bailment contracts.
Knowlton, Jerome C. "The American Mutuum." Mich. L. J. 1, no. 10 (1892): 341-7.