For on the one hand, the former are particular cases where it is only this transfer of goods which enables me to perform my side of the agreement and where my obligation to perform it refers to the thing in question only in so far as it has come into my hands, as with loans, contracts of lease, and deposits (and as may be the case with other contracts, too) a circumstance which concerns not the nature of the relationship between stipulation and perform ance, but the manner of performance itself.