Dialect is local colour individualised. Ian Maclaren, in "The Bonnie Brier Bush," following in the wake of Crockett and Barrie, has given us the dialect of Scotland: Baring Gould and a host of others have provided us with dialect stories of English counties; Jane Barlow and several Irish writers deal with the sister island; Wales has not been forgotten; and the American novelists have their big territory mapped out into convenient sections. Soon the acreage of locality literature will have been completely "written up"; I do not say its yielding powers will have been exhausted, for, as with other species of local colour, dialect has had to suffer at the hands of the imitator who dragged dialect into his paltry narrative for its own sake, and to give him the opportunity of providing the reader with a glossary.
The reason why dialect-stories were so popular some time ago is twofold. First, dialect imparts a flavour to a narrative, especially when it is in contrast to educated utterances on the part of other characters. But the chief reason is that dialect people have more character than other people—as a rule. They afford greater scope for literary artistry than can be found in life a stage or two higher, with its correctness and artificiality. St Beuve said, "All peasants have style." Yes; that is the truth exactly. There is an individuality about the peasant that is absent from the town-dweller, and this fact explains the piquancy of many novels that owe their popularity to the representations of the rustic population. The dialect story, or novel, cannot hope for permanency unless it contains elements of universal interest. The emphasis laid on a certain type of speech stamps such a literary production with the brand of narrowness. I understand that Ian Maclaren has been translated into French. Can you imagine Drumsheugh in Gallic? or Jamie Soutar? Never. Only that which is literature in the highest sense can be translated into another language; hence the life of corners in Scotland, or elsewhere, has no special interest for the world in general.
The rule as to dealing with dialect is quite simple. Never use the letters of the alphabet to reproduce the sound of such language in a literal manner. Suggest dialect; that is all. Have nothing to do with glossaries. People hate dictionaries, however brief, when they read fiction. George Eliot and Thomas Hardy are good models of the wise use of county speech.
Excerpt from "How to Write a Novel"