I have adopted certain tests of form, meaning, and distribution. With regard to the test of the form of a word great care must be exercised. Old Norse and Old Northumbrian have a great many characteristics in common, and some of these are the very ones in which Old Northumbrian differs from West Saxon. It has, consequently, in not a few cases, been difficult to decide whether a word is a loanword or not. Tests that apply in the South prove nothing for the North. Brate rightly regarded _leȝȝkenn_ in the Ormulum as a Scandinavian loanword, but in Middle Scotch _laiken_ or _laken_ would be the form of the word whether Norse or genuine English. Certain well-known tests of form, however, first formulated by Brate, such as _ou_ for O.E. _ea_, or the assimilation of certain consonants apply as well to Scotch as to Early Middle English. The distribution of a word in English dialects frequently helps to ascertain its real history, and may become a final test where those of form and meaning leave us in doubt. In the study of Norse or Scandinavian influence on Lowland Scotch the question of Gaelic influence cannot be overlooked. The extent of Norse influence on Celtic in Caithness, Sutherland and the Western Highlands, has never been ascertained, nor the influence of Celtic on Lowland Scotch. A large number of Scandinavian loanwords are common to Gaelic, Irish, and Lowland Scotch. It is possible that some of these have come into Scotch through Gaelic and not directly from Norse. Perhaps _faid_, "a company of hunters," is such a word.
There are no works bearing directly on the subject of Scandinavian elements in Lowland Scotch proper. J. Jakobsen's work, "Det norrøne Sprog på Shetland," has sometimes given me valuable hints. From Brate's well-known work on the Ormulum I have derived a great deal of help. Steenstrup's "Danelag" has been of assistance to me, as also Kluge's "Geschichte der englischen Sprache" in Paul's Grundriss, the latter especially with regard to characteristics of Northern English. Wall's work on "Scandinavian Elements in English Dialects" has been especially helpful because of the excellent list of loanwords given. In many cases, however, my own investigations have led me to different conclusions, principally with regard to certain tests and the dialectal provenience of loanwords. Finally, the excellent editions of Scottish texts published by the S.T.S. and the E.E.T.S. have made the work less difficult than it otherwise would have been. I may mention particularly "The Bruce," Dunbar, and Montgomery, where Scandinavian elements are very prominent.