a right said, according to the original practice, Spondesne? "Do you promise?" to which the other replied, Spondeo, "I promise." But in later time any other suitable words might be used, e.g. Dabisne? "Will you give?" Dabo, "I will give." The essential was that the answer should not add to or vary the scope and conditions contained in the questions: the agreement had to be precise. A record in writing was very usual, but not necessary, provided the stipulation could be proved by witnesses. The drawback in stipulation, viz., that it required the stipulator and promiser to meet, was to some extent removed by the use of slaves or children, for they could stipulate (though not promise) on behalf of their master or father, and the fact that they were under his power made the contract at once his contract. A free person sui juris could only stipulate for himself, and thus could not act as a mere channel pipe for another. Stipulation however had this great convenience that it was applicable to any kind of agreement, and at once elevated a mere pactum into a strict, valid contract. The pactum was usually put in writing and the fact of its having been confirmed by a stipulation was added to the record. If a promise was stated, the law presumed it to be in reply to an appropriate question: where consent was recorded, no special form of words was necessary (472). A law of Justinian (531) enacted that such record should not be disputable, whether the stipulation was effected through a slave or by both parties themselves: if it stated that the slave had done it, he should be deemed to have belonged to the party and to have been present: if it stated the latter, the parties should be deemed to have been present in person, unless it was proved by the very clearest evidence (Justinian delights in superlatives) that one of the parties was not in the town on the day named.
A very important contract, resting on a transfer of ownership, was mutuum, i.e. loan of money or of corn or any other matters (often called "fungibles") in which quantity and not identity is regarded, one sum of money being as good as any other equal sum. The lender was entitled to recover the same quantity at the agreed time, but had no implied right to interest unless the debtor made delay. A loan was therefore usually accompanied by a stipulation for interest. Justinian however in 536 enacted that a mere agreement was enough to secure interest to bankers. If no day for payment of a loan was named, the debtor might await creditor's application. Part payment could not be refused. Justinian (531) gave to a debtor on loan as in other cases a right to set off against a creditor's claim any debt clearly due from him.
The rate of interest was limited by law. In Cicero's time and afterwards it was not to exceed 12 per cent. per annum. Justinian forbad illustres to ask more than 4 per cent. per annum. Traders were limited to 8 per cent.; other persons to 6 per cent. But interest on bottomry might go up to 12 or 12½ per cent. (= ⅛) during the
