A few words of personal explanation are due to those who may have seen, in the Preface to the First Volume of my edition of the Rig-Veda, a note announcing as ready for publication an Introductory Memoir on the Literature of the Veda. Ten sheets of this Memoir were printed when, in the beginning of the year 1851, 1 was appointed Deputy Professor, and, after the death of my lamented friend, Francis Trithen, in the year 1854, Professor of Modern European Languages and Literature in the University of Oxford. In compliance with the statutes for the Foundation of Sir Robert Taylor, I had to write "Three Courses of Lectures in every year, on the Philology or Literature of some of the principal Languages of Europe." These new and unexpected duties rendered it necessary for me to discontinue for a time my favourite studies.