Intimately connected with compilation is arrangement, for however well the contents of a book may be analysed, the result will not form a good Index unless it is well arranged.

An Index should be one and indivisible, and not broken up into several alphabets, thus every work ought to have its complete Index whether it is one volume or many. This important rule has frequently been neglected in English books, and is almost universally rejected in Foreign ones, to the great inconvenience of readers. An Index may be arranged either chronologically, alphabetically, or according to classes, but great confusion will be caused by uniting the three. The alphabetical arrangement is so simple, so convenient, and so easily understood by all, that it has naturally superseded the other forms, but some still cling to the rags of classification, in the belief that that is a more scientific arrangement. The evil of this is that the consulter is never sure whether the reference he requires may not be lurking in some place that he has missed, but in the case of a single alphabet an answer to the question “Does the Index contain what I require?” is obtained at once.