It is, lastly, plain that such success as may be attained in the attempt to lay before the British public thoughts on the Union must, at bottom, depend upon the labours of men who for the last sixty years and more have investigated with infinite care the many different and important aspects of Scottish history, and who have thrown year by year more and more light on the parliamentary history of Scotland both up to and after the passing of the Act of Union. On the facts established by this patriotic and successful effort the commentary put forward in this essay depends. It is here both a pleasure and a duty to acknow ledge the infinite help given in the preparation of this book by friendly communications, by men com petent to speak — one of them, alas, is now for ever silent — with special authority as to different subjects on which these Thoughts at times touch. We are specially indebted to the late Professor Hume Brown.