Four years after the publication of this work, and after a residence of thirteen years in Glasgow, Mr. Smith, in 1763, was induced to relinquish his professorship, by an invitation from the Hon. Mr. Townsend, who had married the Duchess of Buccleugh, to accompany the young Duke, her son, in his travels. Being indebted for this invitation to his own talents alone, it must have appeared peculiarly flattering to him. Such an appointment was, besides, the more acceptable, as it afforded him a better opportunity of becoming acquainted with the internal policy of other states, and of completing that system of political economy, the principles of which he had previously delivered in his lectures, and which it was then the leading object of his studies to perfect. Mr. Smith did not, however, resign his professorship till the day after his arrival in Paris, in February 1764. He then addressed the following letter to the Right Honourable Thomas Millar, lord advocate of Scotland, and then rector of the college of Glasgow:-- 'MY LORD,--I take this first opportunity after my arrival in this place, which was not till yesterday, to resign my office into the hands of your lordship, of the dean of faculty, of the principal of the college, and of all my other most respectable and worthy colleagues. Into your and their hands, therefore, I do resign my office of professor of moral philosophy in the university of Glasgow, and in the college thereof, with all the emoluments, privileges, and advantages, which belong to it. I reserve, however, my right to the salary for the current half-year, which commenced at the 10th of October, for one part of my salary, and at Martinmas last for another; and I desire that this salary may be paid to the gentleman who does that part of my duty which I was obliged to leave undone, in the manner agreed on between my very worthy colleagues before we parted. I never was more anxious for the good of the college than at this moment; and I sincerely wish, that whoever is my successor, he may not only do credit to the office by his abilities, but be a comfort to the very excellent men with whom he is likely to spend his life, by the probity of his heart and the goodness of his temper.' His lordship having transmitted the above to the professors, a meeting was held; on which occasion the following honourable testimony of the sense they entertained of the worth of their former colleague was entered in their minutes:--