igations of men to each other under promises, benefits, and
injuries. Lord Mackenzie treats the subject in the order of the
Institutes:--

"Obligations contracted _re_--by the intervention of _things_--are
called by the moderns real contracts, because they are not perfected
till something has passed from one party to another. Of this description
are the contracts of loan, deposit, and pledge,--security for
indebtedness. Till the subject is actually lent, deposited, or pledged,
it does not form the special contract of loan, deposit, or pledge."

Next to the perfection of contracts by _re_,--the intervention of
things,--were obligations contracted by _verbis_, spoken _words_, and by
_literis_, or writings. The _verborum obligatio_ was contracted by
uttering certain words of formal style,--an interrogation being put by
one party, and an answer given by the other. These stipulations were
binding. In England all guarantees must be in writing.

The _obligatio literis_ was a written acknowledgment of debt, chiefly
employed when money was borrowed; but the creditor could not sue upon a
note within two years from its date, without being called upon also to
prove that the money was in fact paid to the debtor.

Contracts perfected by consent, _consensu_, had reference to sale,
hiring; partnership, and mandate, or orders to be carried out by agents.
All contracts of sale were good without writing.

Acts which caused damage to another opened a new class of cases. The
law obliged the wrong-doer to make reparation, and this responsibility
extended to damages arising not only from positive acts, but from
negligence or imprudence. In cases of libel or slander, the truth of the
allegation might be pleaded in justification. In all cases it was
necessary to show that an injury had been committed maliciously; but if
damage arose in the exercise of a right, as killing a slave in
self-defence, no claim for reparation could be maintained. If any one
exercised a profession or trade for which he was not qualified, he was
liable to all the damage his want of skill or knowledge might
occasion,--a provision that some of our modern laws might advantageously
revive. When any damage was done by a slave or an animal, the owner of
the same was liable for the loss, though the mischief was done without
his knowledge and against his will. If anything was thrown from a window
giving on the public thoroughfare so as to injure any one by the fall,
the oc