In the winter of 1831 he commenced his studies in the Divinity Hall under Dr. Chalmers, and the study of Church History under Dr. Welsh.  It may be naturally asked, What led him to wish to preach salvation to his fellow-sinners?  Could he say, like Robert Bruce, “I was first called to my grace, before I obeyed my calling to the ministry?” Few questions are more interesting than this; and our answer to it will open up some of the wonderful ways of Him “whose path is in the great waters, and whose footsteps are not known,” Psalm 77:19; for the same event that awakened his soul to a true sense of sin and misery, led him to the ministry.

During his attendance at the literary and philosophical classes he felt occasional impressions, none of them perhaps of much depth.  There can be no doubt that he himself looked upon the death of his eldest brother, David, as the event which awoke him from the sleep of nature, and brought the first beam of divine light into his soul.  By that providence the Lord was calling one soul to enjoy the treasures of grace, while He took the other into the possession of glory.

In this brother, who was his senior by eight or nine years, the light of divine grace shone before men with rare and solemn loveliness.  His classical attainments were very high; and, after the usual preliminary studies, he had been admitted Writer to the Signet.  One distinguishing quality of his character was his sensitive truthfulness.  In a moment would the shadow flit across his brow, if any incident were related wherein there was the slightest exaggeration; or even when nothing but truth was spoken, if only the deliverer seemed to take up a false or exaggerated view.  He must not merely speak the whole truth himself, but he must have the hearer also to apprehend the whole truth.  He spent much of his leisure hours in attending to the younger members of the family.  Tender and affectionate, his grieved look when they vexed him by resisting his counsels, had (it is said) something in it so persuasive that it never failed in the end to prevail on those with whom his words had not succeeded.  His youngest brother, at a time when he lived according to the course of this world, was the subject of many of his fervent prayers.  But a deep melancholy, in a great degree the effect of bodily ailments, settled down on David’s soul.  Many weary months did he spend in awful gloom, till the trouble of his soul wasted away his body:  but the light broke in before his death; joy from the face of a fully reconciled Father above lighted up his face; and the peace of his last days was the sweet consolation left to his afflicted friends, when, 8th July 1851, he fell asleep in Jesus.