The collection comprises thirteen manuscript volumes, each of which contains numerous illustrations as well as transcriptions of letters originally composed while Forbes was in India, with a particular concentration on the natural history of India. The manuscript was finished in 1800, although most of the drawings are those done at the time of the voyage, circa 1765-1776. Volume 1 includes a presentation page, dated 11 April 1800, in which Forbes gives the set to his daughter, Elizabeth Rosée Forbes. Elizabeth would later edit and revise the second edition of Forbes's Oriental memoirs (1834).