If you are a man and your introduction is to a lady, you go to her house as soon as you arrive in her city, and leave the letter with your card at her door. Usually you do not ask to see her; but if it is between four and six o'clock it is quite correct to do so if you choose. Presenting yourself with a letter is always a little awkward. Most people prefer to leave their cards without asking to be received. If your letter is to a man, you mail it to his house, unless the letter is a business one. In the latter case you go to his office, and send in your card and the letter. Meanwhile you wait in the reception room until he has read the letter and sends for you to come into his private office. If you are a woman, you mail your letter of social introduction and do nothing further until you receive an acknowledgment. If the recipient of your letter leaves her card on you, you in return leave yours on her. But the obligation of a written introduction is such that only illness can excuse her not asking you to her house--either formally or informally. When a man receives a letter introducing another man, he calls the person introduced on the telephone and asks how he may be of service to him. If he does not invite the newcomer to his house, he may put him up at his club, or have him take luncheon or dinner at a restaurant, as the circumstances seem to warrant. CHAPTER III GREETINGS =WHAT TO SAY WHEN INTRODUCED= As explained in the foregoing chapter, the correct formal greeting is: "How do you do?" If Mrs. Younger is presented to Mrs. Worldly, Mrs. Worldly says "How do you do?" If the Ambassador of France is presented to her, she says "How do you do?" Mrs. Younger and the Ambassador likewise say "How do you do?" or merely bow. There are a few expressions possible under other circumstances and upon other occasions. If you have, through friends in common, long heard of a certain lady, or gentleman, and you know that she, or he, also has heard much of you, you may say when you are introduced to her: "I am very glad to meet you," or "I am delighted to meet you at last!" Do not use the expression "pleased to meet you" then or on any occasion. And you must not say you are delighted unless you have reason to be sure that she also is delighted to meet you. To one who has volunteered to help you in charitable work for instance, you would say: "It is very good of you to help us," or, "to join us." In business a gentleman says: "Very glad to meet you," or "Delighted to meet you." Or, if in his own office: "Very glad to see you!" =INFORMAL GREETINGS= Informal greetings are almost as limited as formal, but not quite; for besides saying "How do you do?" you can say "Good morning" and on occasions "How are you?" or "Good evening."