were his own. _In rebus commodatis tails diligentia proestanda est,
qualem quisque diligentissimus paterfamilias suis rebus adhibet_.
[Footnote: D. 13, 6, 1 pr.] He could only use a thing for the purpose for
which it was lent; he could not keep it beyond the time agreed upon, nor
detain it as a set-off against any debt. He was bound to restore the
article in the same condition as received, subject only to the
deterioration arising from reasonable use, whether a horse, a house, or
a carriage. And he was required to make good all injuries caused by his
own fault or negligence. If the article perished, without any blame or
neglect, the loss fell on the owner. If the loan was for consumption,
which was called _mutuum_, like corn, or oil, or wine, the borrower
was required to return as much of the same kind and quality, whether the
price of the commodity had risen or fallen. In a loan of money, under
_mutuum_, the borrower was not required to pay interest. Interest
was only due _ex lege_, or by agreement. The rate varied at
different times; generally, it was eight and one third per cent., and
even more than this in the latter years of the republic. Justinian
introduced a scale which varied with different classes of society.
Persons of illustrious rank could lend money at four per cent., ordinary
people at six, and for maritime risks twelve; but it was unlawful to
charge interest upon interest. [Footnote: C. 4, 32, 26, Section 1.]
Property would double, at eight and one third, in twelve years, not so
rapidly as by our system of compound interest, especially at the rate of
seven per cent. In England the usury laws of different monarchs limited
interest from ten per cent, to five; but these were repealed in 1854.
Only five per cent. can now be recovered upon any contract.

[Sidenote: Deposits.]

A deposit differed from a loan in this,--that the depositary was not