The Inverness Lunacy District, which was formed after the passing of the Lunacy Act of 1857, comprises the four counties of Nairn, Inverness, Ross, and Sutherland, and is of very large extent. Its area is, roughly, one-third of the total area of Scotland, and includes the greater part of the Highlands. Its population, on the other hand, is extremely sparse, and has been steadily decreasing during the last fifty years. It is a district in which there has been much intermarriage of relatives, and which is less open and accessible than most of the rest of Scotland to the factors that have brought about such great changes in the general life of the country during the last fifty years. In recent years, however, the extension of railways, and the wide use of motor cars, have done much to diminish this degree of isolation and remoteness.