When personal calls are not practicable, nor desirable, the leaving of
cards is accepted as an equivalent.
A few years ago, fashion demanded that all visiting-cards expressing or
acknowledging social civilities should be left in person; the
alternative in emergencies being to send them by the hand of a private
messenger, never through the post-office. There was good excuse for
this fashion in our grandmother's day, when the post was a slow coach,
or a storm-stayed postillion; but the admirable system of our postal
service to-day leaves no excuse for the prejudice in favor of the
private messenger; and it is not surprising that fashion has yielded to
common sense in allowing that many of these cards of courtesy may, with
perfect propriety, be sent by post.
The following instances illustrate the present correct usage in regard
to these three ways of leaving cards.