inhabitants of those districts, in the vicinity, and forming a part of a great nation far advanced in knowledge and in wealth, appear to be chiefly those which determine the amount of intercourse between them. Where that intercourse is easy and constant, the process of assimilation proceeds rapidly, and the result is as certain as that of opening the sluices in the ascending lock of a canal. Where that intercourse is impeded, or has not been established, it may perhaps be possible to institute a separate local civilization, an isolated social progress; but an instance of its successful accomplishment is not to be found in those districts. “Whatever tends to facilitate and promote intercourse between the distressed districts and the more advanced parts of the country, tends to assimilate the habits and modes of life of their inhabitants, and, therefore, to promote education, industry, good management, and everything in which the great body excels the small portion that is to be assimilated to it.”[92] Notwithstanding the immense number of people who have emigrated from the Highlands during the last 100 years, the population of the six chief Highland counties, including the Islands, was in 1861 upwards of 100,000 more than it was in 1755. In the latter year the number of inhabitants in Argyll, Inverness, Caithness, Perth, Ross, and Sutherland, was 332,332; in 1790-98 it was 392,263, which, by 1821, had increased to 447,307; in 1861 it had reached 449,875. Thus, although latterly, happily, the rate of increase has been small compared with what it was during last century, any fear of the depopulation of the Highlands is totally unfounded.