Disciples of Light contains almost two hundred of the earliest known English and Scottish photographs, most of which have never been published. The volume includes all the significant photographs in the album, compiled by Sir David Brewster, an important early patron of photography. Photographs by William Henry Fox Talbot, the inventor of negative-positive paper photography, are included, as well as works by other photographers who improved upon Talbot's invention. The text discusses the context in which the album was compiled, the personalities of the photographers, and the groups of specific images that it contains. Numerous comparative illustrations are included, as well as a checklist of all photographic images, a bibliography, and an index of all proper names and place names.

The Clan Chisholm is said to descend to have Norman origins and to have come from the borders of Scotland. However, for over six hundred years the clan has been associated with the highlands of Scotland, particularly Inverness, Sutherland, Ross and Caithness.

The tragedy of the Clearances, brought about by cynical, often absentee landlords, is a black page in Scotland's history. Written while the effects it describes were still unfolding, Mackenzie's history brings the distress before the reader.