Anonymous communications are both cowardly and ill-bred. Under no circumstances should they be written. The fire is the only fit asylum for them when received. The Gunpowder Plot might have been revealed openhandedly, and the anonymous letter even in that case nearly missed its aim. The only anonymous communications which can be tolerated are the harmless missives called valentines. These, however, have fallen out of favor in polite society. Children and servants are the chief supporters of the manufacturers of the gorgeous love-letters. In writing to a person who is the guest of another, take care to place the name of the host or hostess on the cover of your letter. Some people address the letter in such a case to the host, and inscribe the name of their correspondent in the left-hand corner, thus: JAMES GORDON, ESQ., No. 347 --- Street, New York. For Mrs. T. C. BATES. This practice is very likely to lead to an unintentional opening of the letter by the wrong person; for a cursory glance at the cover would seem to show that the letter was intended for the person whose name was most prominent. The letter should have been directed, to the person for whom it was intended first, thus: Mrs. T. C. BATES, Care of JAMES GORDON, Esq., No. 347 --- Street, New York. Unless very well acquainted with your correspondent, do not use terms implying intimacy. Business letters usually commence with "Sir," "Gentlemen," "Dear Sir," or "Dear Sirs," and end with, "I am, Sir (or Gentlemen), Your obedient servant," etc. Official letters invariably begin with the title of the person addressed, and then "Sir," if a civilian or the rank of an officer. If the letter be to the head of a Department, to a high Government official, or to a superior officer, it is customary to write in a strain a little more deferential than ordinary, so that, instead of saying, as you would to a friend, "I have to acquaint you," "I have to acknowledge the receipt of your letter," you would say, "I have the honor to acknowledge." The ending, too, of such letters should be slightly different: "I have the honor to be, General, Your obedient servant," taking the place of "I am, sir," etc. In official communications, margins are always left, so as to allow of notations being made for the purpose of framing an answer, and the backs of the pages should be left blank for the same purpose. It is not customary to write down quite to the bottom of the page, but to take ample room for the substance of the letter. Unless writing officially, or to some public person, it is not customary in this country to give a man all the titles which may belong to him.