The occasion which gave rise to these notes was the discovery three years ago, at Blickling in Norfolk, of the diplomatic papers of John Hobart, second Earl of Bucking-hamshire, who was ambassador to the Court of Russia from 1762 to 1765. These were entrusted to me by their owner, Constance, Marchioness of Lothian, to examine and catalogue, and among them, it soon became evident, were notes and memoranda relating to questions of a much earlier date than that of Lord Buckinghamshire's mission, which it was of interest to trace to their source.