Mr. Parry, in his answer 7351 (Minutes, p. 470), advocates the plan of having a separate index of subjects, and in spite of all that has been said in favour of dictionary catalogues, I hold that this is the simplest and most useful for students; although for popular libraries there is much to be said in favour of dictionary catalogues. One of the most elaborate indexes I know is that by my brother, Mr. B. R. Wheatley, for the Catalogue of the Royal Medical and Chirurgical Society. By this plan he who knows what he wants finds it without being confused by, to him, useless references, while he who does not know can consult the index.
In an index the headings will of course be in alphabet, and the sub-headings may be so also; but often some system of classification will be better. No hard-and-fast rule can be made for all cases. But it is usually better to bring the subjects of the books together, regardless of the wording of the title.
CHAPTER VI.
ARRANGEMENT.
Rule II. of the British Museum is: "Titles to be arranged alphabetically, according to the English alphabet only (whatever be the order of the alphabet in which a foreign name might have been entered in its original language);" and this rule has been generally followed. Mr. Cutter (rule 169) adds to this, "Treat I and J, U and V, as separate letters;" and every consulter of the British Museum Catalogue must wish that this rule was adopted there, for anything so confusing as this unnecessary mixing of the letters I and J and U and V it is scarcely possible to imagine. Mr. Cutter goes on: "ij, at least in the olden Dutch names, should be arranged as y; do not put Spanish names beginning with Ch, Ll, Ñ, after all other names beginning with C, L, and N, as is done by the Spanish Academy."
The Museum rule (XIII.) is: "German names in which the letters ä, ö, or ü occur, to be spelt with the diphthong æ, œ, and ue respectively."