This gentleman was the son of Sir William Nairne, the second baronet of Dunsinnan. Not being the oldest son, and having only a distant prospect of succeeding to the estate, he was educated for the profession of the law, and admitted an advocate in 1755. He was, in 1758, appointed Commissary-Clerk of Edinburgh, conjunctly with Alexander Nairne, a relative of his own. Sir William (then Mr. Nairn*;), continued to practise at the bar upwards of thirty years; and, if he did not acquire the fame of a great orator or a profound lawyer, he was at least respectable in both capacities, and his virtues gained him what was perhaps better—the esteem of all who knew him.

On the death of Lord Kennet, in 1786, Sir William was promoted to the bench, and took his seat as Lord Dunsinnau—a circumstance which called forth the following complimentary pun from the late Duchess of Gordon. A short time after his elevation, her grace, happening to meet the newly appointed judge, inquired what title he had assumed—Dunsinnan was of course the reply. "I am astonished at that, my lord," said the Duchess, "for I never knew that you had begun sinning."

In 1790 Sir William succeeded to the baronetcy, on the death of his nephew, and thus became the fifth in succession who bore the title. He, at the same time, bought the estate of Dunsinnau from another nephew, for the sum of .£16,000; and having almost no funds remaining, he was under the necessity of adopting the utmost economy in order to clear off the purchase money. With this view he continued to live a bachelor, keeping almost no company; and so strictly did he abide by the rules he had laid down in this respect, that he was accused by many of being actuated by very narrow and parsimonious feelings. It is told of him, as illustrative of his peculiar economy, that he had only one bed at Dunsinnan, besides those occupied by his servants, thus to preclude the possibility of being put to the expense of entertaining visitors. It so occurred that the late George Dempster of Dunnichen, one of the most intimate of the very few friends with whom his lordship associated, paid him a visit at Dunsinnan on one occasion; and having tarried a little later than usual, a violent storm arose, which induced Mr. Dempster to think of remaining all night. Dunsinnan, unwilling to declare the inhospitable arrangement of his mansion, evaded the proposition by every means possible, in hopes that the storm might abate. At last, finding no likelihood of this, he sallied forth to the stable to order his friend's coach to the door, as the only effectual hint to his guest; but Dempster's coachman was not to be so caught: he positively refused to harness the horses in such a night, especially as the roads were so bad and dangerous, preferring rather to lie in the stable, if he could get no other accommodation, till daylight. Lord Dunsinnan, thus driven to extremities, returned to his guest, and made known the dilemma in which they were placed. "George," said he, "if you stay, you will go to bed at ten and rise at three ; aud then I shall get the bed after you."

The property of Dunsinnan, which included nearly the entire parish of Collace, was far from being in a state of improvement when it came into his hands; a great part of the lands consisted of what is termed "outfield," and the farms were made up of detached portions, many of these at considerable distances. No sooner had Sir William obtained possession of the estate than he set about dividing the lands into compact and regular farms, which he enclosed, and gave to each a certain portion of outfield; at the same time he built comfortable dwellings for many of his tenants, and, by proper encouragement, induced others to do so for themselves. He thus, with no niggardly hand, promoted alike the prosperity of the tenant, and ensured the rapid improvement of the soil.

Sir William was appointed a Lord of Justiciary, in 1792, on the death of Lord Stonefield; and continued to attend the duties of the circuit until 180S, when he resigned, and the following year retired from the Court of Session altogether. He died, at a very advanced age, at Dunsinnan House, on the 25th March, 1811. The title became extinct in his person, and a nephew (his sister's son) succeeded to the estate and assumed the name of Nairne.

His lordship's residence in Edinburgh was Minto House, Argyle Square. Previous to his removal thither, he occupied a tenement at the head of the Parliament Stairs, lately a printing-office; but now removed to make way for the new Justiciary Court-Room.

Before concluding this sketch, it may be noticed that Lord Dunsinnan was uncle to the famous Catherine Nairne or Ogilvie, whose trial, in 1765, for the crimes of murder and incest, excited such general interest. She married, in that year, Thomas Ogilvie, Esq. of Eastmiln, Forfarshire—a gentleman, as was stated at the trial, of forty years of age and of a sickly constitution—the lady's own age being only nineteen. Shortly before the marriage, a younger brother of this gentleman, named Patrick, and a lieutenant in the 89th foot, had returned, on account of bad health, from India, and had taken up his residence as a visitor at his brother's house. The marriage took place three or four days after Patrick's return; and, in less than a week, the intercourse betwixt him and his brother's wife, which led to such tragical consequences, was stated to have commenced. Four months afterwards, in pursuance of a diabolical plot betwixt Mrs. Ogilvie and her seducer, the former effected the death of her husband by means of arsenic. She and her accomplice were accordingly brought to trial, when both were found guilty, and condemned to be hanged. Sentence was executed upon Patrick Ogilvie, in the Grassrnarket of Edinburgh; but Catherine Nairne, whose sentence had been delayed in consequence of pregnancy, made her escape from the tolbooth soon after her accouchement. She effected this by assuming the garb and demeanour of the midwife, Mrs. Shiells, who had, for several days previously, attended on her patient with her head muffled up, under pretence of a violent attack of toothache.

There is every reason to believe that the stratagem was matured under the connivance of her uncle Sir William, then Mr. Nairne; and, at least, some of the prison guards were not ignorant of what was to take place. There have been various conjectures as to the precise time Catherine Nairn quitted the city—some asserting that she remained concealed in Edinburgh for some days prior to her flight to the continent. It appears almost certain, however, that she left the city the same night (Saturday the 15th March, 1766) on which she escaped from the jail;—a carriage was in waiting at the foot of the Horse Wynd, in which was Mr. Nairne's clerk—the late Mr. James Bremner, afterwards solicitor of Stamps—who accompanied Mrs. Ogilvie as far as Dover, on her way to France.