Letters of introduction are one of the common methods of establishing social relations. The person who is not known to your friend can become known through your kind offices. In this way, very often, important services can be rendered.

Never give a letter of introduction unless you thoroughly understand the character and manners of the person to whom you write the letter and also of the person whom the letter introduces.

You have no right, to avoid giving offence, or through sheer inability to say no to a request, to foist upon your distant friend some one for whose acquaintance he will not thank you and who may prove a very undesirable visitor. If one or the other of the two parties concerned must be offended, let it be the applicant. You can usually give some sufficient reason for declining--but decline in any event, if the person is likely to prove objectionable.

As such a letter cannot well enter into particulars, it is customary and desirable to notify your friend by mail of the fact that you have given a letter of introduction to such a person, and tell him what further it is well for him to know concerning the character and purpose of his probable visitor. If you have given such a letter to a party of whom you do not approve, all that remains is to warn your friend privately, placing him on his guard against a possibly objectionable person.

A letter of introduction (unless sent by mail) should be delivered, unsealed, by the writer of the letter to the bearer of the introduction, and should be closed by the latter before delivery to the party to whom it is addressed. If purely a business introduction and one which can be delivered personally, it may remain unsealed.

The bearer of a letter of introduction should send it to the house of the person to whom it is addressed, together with a card on which should be written his address. It is not in order to deliver it in person, since this may force the party addressed into a position which he may prefer to decline. It does not follow, because a friend has chosen to introduce you to another, that this other may not have private reasons for declining your acquaintance, or may be prevented from seeing and entertaining you by stress of other engagements. If he lives in a large city, the letter may make him feel obliged to escort you to the various places of interest, or in any case to invite you to meals or other entertainments. We should not tax the time or the purse of a friend, except for a satisfactory reason.

The letter delivered, there is nothing more to be done until the party receiving it calls upon you or sends you some card or note of invitation. Those who receive such letters should, within twenty-four hours, if possible, take some kindly notice of them by a call or an invitation.

A letter of introduction must be carefully worded, stating clearly the name of the person introduced, but with as few personal remarks as possible. It suffices in most cases to say that the bearer is a friend of yours, whom you trust your other friend will receive with attention, or you may state his profession, object in traveling, etc. In traveling, one cannot have too many letters of introduction. It is the custom in foreign towns for the newcomer to call on the residents first, a hint that may prove acceptable to persons contemplating a long or short residence abroad.

A letter of introduction of a business nature may be delivered by the bearer in person, since it requires no social obligations. In style it should resemble other business letters; that is, it should be brief and to the point.

If a stranger sends you a letter of introduction, and his or her card (for the law of etiquette here holds good for both sexes), good form requires that you should not only call next day, but follow up that attention by others. If you are in a position to do so, the next correct proceeding is to send an invitation to dinner. Should circumstances not render this available, you can probably escort the stranger to some exhibition, concert, public building, museum, or other place likely to prove interesting to a foreigner or provincial visitor. In short, etiquette demands that you shall exert yourself to show kindness in some desirable way to the stranger, out of compliment to the friend who introduced him to you.

If you invite strangers to dinner or tea, it is a higher compliment to ask others to meet them than to dine with them alone. You thereby afford them an opportunity of making other acquaintances, and are assisting your friend in still further promoting the purpose for which he gave the introduction to yourself. Be careful at the same time only to ask such persons as you are quite sure are the stranger's own social equals.