In the admirable new edition of "Jamieson" by Longmuir and Donaldson, published at Paisley in 1879, this matter is set right.

They quite rightly reprint this "Dissertation," which affords valuable testimony as to the study of English in 1808, but accompany it with most judicious remarks, which are well worthy of full repetition.
"That once famous Dissertation can now be considered only a notable feat of literary card-building; more remarkable for the skill and ingenuity of its construction than for its architectural correctness, strength and durability, or practical usefulness.

That the language of the Scottish Lowlands is in all important particulars the same as that of the northern counties of England, will be evident to any unbiassed reader who takes the trouble to compare the Scottish Dictionary with the Glossaries of Brockett, Atkinson, and Peacock.
And the similarity is attested in another way by the simple but important fact, that regarding some of our Northern Metrical Romances it is still disputed whether they were composed to the north or the south of the Tweed....

And to this conclusion all competent scholars have given their consent." For those who really understand the situation there is no harm in accepting the distinction between "Scottish" and "English," as explained above.

Hence it is that the name of "Middle Scots" has been suggested for "the literary language of Scotland written between the latter half of the fifteenth century and the early decades of the seventeenth." Most of this literature is highly interesting, at any rate much more so than the "English" literature of the same period, as has been repeatedly remarked.