Dr. Duncan was imbued with a spirit of enlarged Christian benevolence, and felt a peculiar interest in the amelioration of the condition of the poorer classes. Hence he formed the scheme of the "Cheap Repository Tracts," addressed to the working classes, and designed to enforce the most useful lessons suited to their condition. It was in this collection that his "Cottage Fireside" was first published, a production which became exceedingly popular, and passed through many editions. The book abounds in happy delineations of Scottish manners, fine strokes of humor, and admirable lessons of practical wisdom. "The South Country Weaver," possesses the same qualities and aims; and, in a time of excessive political excitement, did much to allay the discontent and revolutionary tendency of the people. He is also said to be the author of another work of a higher grade, written in the same style of fictitious narrative, and intended to vindicate the principles and proceedings of the Scottish Covenanters, from the aspersions cast upon them by the author of Waverley. This production has been highly esteemed by good judges of literary merit, but it never became popular. It may well be supposed that Dr. Duncan felt a peculiar interest, not only in the spiritual but also in the temporal condition of his own parish, and hence he was ever devising plans for its benefit. In this respect he much resembled the benevolent Oberlin, whose well directed schemes turned the barren parish of Waldbach into a little paradise. Entering upon the duties of his charge at a time of national scarcity and distress, he imported from Liverpool, at considerable expense, and with great personal inconvenience, large quantities of food which he distributed among his poor parishioners He also devised new modes and sources of employment, and cheered them amid their privations by his counsel and sympathy. He instituted among them two admirable "Friendly Societies," one for males and another for females, the advantages of which are enjoyed to this day. But perhaps his highest claim to distinction as a philanthropist was the establishment of "The Ruthwell Parish Bank," the first "Savings Bank" in Europe, which, it is said, was suggested to him partly by the beneficial results and partly by the admitted defects of the Friendly Societies. His undoubted title to be regarded as the originator of "Savings Banks," has been acknowledged by the highest authorities; but it is not so generally known at what an immense expenditure of time, talent, energy and pecuniary means he succeeded in accomplishing this good object.