On the completion of his legal studies at the university of Edinburgh, Sir James went to the bar, (1734,) but without any intention of prosecuting the law as a profession. He soon after set out upon a tour of the continent, where he formed an acquaintance with the duke of Ormond, the earl Marischal, and other exiled Jacobite chiefs. The family from which he descended had been conspicuous for its attachment to the popular cause, for a century; but Sir James appears to have been converted by these nobles from his original Whig principles. Having permitted himself to be introduced by them to prince Charles Stuart at Rome, he received such civilities from that scion of expatriated royalty, as had a material effect upon the tenor of his future life. He returned to his native country in 1740, with many accomplishments, which added brilliancy to his character, but an unsettled tone of mind, which he afterwards greatly regretted.

Among the intimate friends of Sir James at this period of his life, was Mr Alexander Trotter, the father of one of the present land-proprietors of Mid Lothian. Mr Trotter was cut off in early life; and, during his last illness, made a promise to Sir James, that, if possible, he would come to him after his death, in an enclosure near the house of Coltness, which in summer had been frequently their place of study. It was agreed, in order to prevent mistake or misapprehension, that the hour of meeting should be noon; that Mr Trotter should appear in the dress he usually wore, and that every other circumstance should be exactly conformable to what had commonly happened when they met together. Sir James laid greater stress on this engagement than sound reason will warrant. Both before and after his exile, he never failed, when it was in his power, to attend at the place of appointment, even when the debility arising from gout rendered him hardly able to walk. Every day at noon, while residing at Coltness, he went to challenge the promise of Mr Trotter, and always returned extremely disappointed, that his expectation of his appearance had not been gratified. When rallied on the subject, he always observed seriously, that we do not know enough of "the other world"to entitle us to assume that such an event as the reappearance of Mr Trotter was impossible. We fear, however, that the most of those who peruse this narrative willbe inclined to class this anecdote with the "follies of the wise."

In the course of his travels, Sir James had formed an intimacy with lord Elcho, who, conceiving, in the warmth of youthful friendship, that the young baronet would be able to gain the affections of his sister, lady Frances Wemyss, carried him to Cedar Hall, in the north of Scotland, where that young lady was residing with the countess of Sutherland. As Elcho expected, Sir James gained the heart of lady Frances; and, after some scruples on the part of her relationds had been overcome, they were married in October, 1743, at Dunrobin castle, the lady bringing her husband what was then considered a very handsome fortune, namely, six thousand pounds. A pair more elegant, more amiable, and more accomplished, is rarely seen. Their union was blessed in August, 1744, by the birth of their son, the late Sir James Steuart, who was for many years the principal object of their care.

The subject of our memoir had joined the opposition party, and in the year last named he had an unpleasant collision with the family of Dundas, which was then beginning to take a leading part in Scottish politics. A claim preferred by him to be enrolled amongst the freeholders of Mid-Lothian, was refused; and for this he raised an action against Dundas of Arniston, then one of the senators of the college of justice. In the course of the judicial proceedings, Sir James pled his own cause in so masterly a manner, that lord Arniston descended from the bench, and defended himself at the bar. The cause was given against the young advocate; and this, no doubt, conspired, with other circumstances, to prepare him for the step he took in the subsequent year.

Sir James was residing in Edinburgh, in attendance upon lady Frances, who was then in a state of ill health, when prince Charles, at the head of his Highland army, took possession of the city. Among the principal adherents of the young adventurer, was lord Elcho, the brother-in-law and bosom friend of Sir James Steuart. The latter, with the earl of Buchan, who had married one of his sisters, formed the wish of being introduced to prince Charles, but without pledging themselves to join his standard. They, therefore, induced lord Elcho to seize them at the cross of Edinburgh, and conduct them, apparently as prisoners, into the presence of the prince. Being brought into an antechamber in Holyroodhouse, their friend proceeded to inform his royal highness of their arrival, and of the circumstances under which they approached him; when Charles, with great dignity, refused to see them in any other character than as avowed adherents of his cause. When Elcho returned with this intelligence, the earl of Buchan took his leave; while Sir James, a man greatly excelling that nobleman in intellect, proceeded to offer his services to the young chevalier. He was fortunately saved from the ultimate perils of the campaign, by being immediately despatched on a mission to the French court, where he was at the time of the battle of Culloden. The penalty of his rashness, was an exile of nearly twenty years, being, though not attainted, among the exceptions from the act of indemnity.

Till the year 1763, when George III. permitted him to return home, Sir James Steuart resided abroad with his family, employing his leisure in those studies which he afterwards embodied in his works. He spent the greater part of the period of his exile in the town of Angouleme, where he became intimately acquainted with the French finance system, through a body of counsellors of the parliament of Paris, who were banished to that town for nearly the space of two years. Sir James also spent some time at Frankfort, at Spa, at Venice, and at Padua. When in Germany, he and his lady were received with extraordinary marks of favour at the courts of Wirtemberg, Baden-Dourlach, and Hohenzollern. At Venice, in 1758, he and lady Frances had the good fortune to form a friendship with the celebrated lady Mary Wortley Montagu, who, till the end of her life, corresponded frequently with both, and gave them and their son many proofs of her affection: a series of her ladyship’s letters to Sir James and lady Frances were printed at Greenock, under the care of the late Sir James, in 1818. Though exiled from Britain, on account of disloyalty to the Hanover dynasty, Sir James Steuart never entertained a disloyal feeling towards his country. On the contrary, the enthusiasm with which he rejoiced in the successes of the British arms during the seven years’ war, led to his falling under the suspicion of the French court, and, while residing at Spa, in a neutral territory, a large body of troops was sent to apprehend him, and convey him to prison in the duchy of Luxemburg. It was not for many months that he succeeded in convincing the government of its error, or regained his liberty.

The first work published by Sir James, was a volume, which appeared at Frankfort sur le Main, in 1758, under the title of "Apologie du Sentiment de Monsieur le Chevalier Newton, sur l’ancienne Chronologie des Grecs, contenant des reponses a toutes les objections qui y ont eté faites jusqu’ a present." In the same year, while settled at Tubingen, in Germany, he produced his "Treatise on German Coins," in the German language. It was followed in 1761, by "A Dissertation on the Doctrine and Principles of Money, as applied to the German Coin:" and in the same year, he so far made his peace with the British government, as to obtain a cornetcy in the Royal, or 1^st regiment of dragoons. At the peace of Paris, in 1763, he was tacitly permitted to return home, and resume possession of his estates. It was in retirement at Coltness that he probably put the last hand to his "Inquiry into the Principles of Political Economy," which was published in 1767, in two volumes, quarto. Messrs Miller and Cadell gave five hundred pounds for the copyright of this work, the merits of which were at the time a subject of considerable dispute. It has at least the merit of having been the first considerable work on this subject published in Britain, being about nine years antecedent to the work of Dr Smith. In 1769, Sir James published, under the assumed name of Robert Frame, "Considerations on the Interests of the County of Lanark." By the interest of his friends, he now obtained a full pardon, which passed the great seal 1771; and in the year following, he printed "The Principles of Money applied to the present state of the Coin of Bengal." He also wrote, "A Plan for introducing an uniformity of Weights and Measures," which was published after his death. He likewise published, "Observations on Beattie’s Essay on Truth:" "Critical Remarks on the Atheistical Falsehoods of Mirabaud’s System of Nature:" and "A Dissertation concerning the Motice of Obedience to the Law of God." It is supposed that the ardour and assiduity with he pursued his studies, proved detrimental to his health. An inflammation, commencing with a toe-nail too nearly cut, put an end to his valuable life, on the 26th of November, 1780. His remains were interred in the family vault at Cambusnethan church, and a monument has been erected to his memory in Westminster abbey.