The Bute administration, brief as it was, is memorable for the patronage which it extended to literature. The minister, himself a man of letters and of science, wished that the new reign should be the commencement of an Augustan era; and he accordingly was the means of directing the attention of the young monarch to a number of objects, which had hitherto languished for want of the crown patronage. One of the most remarkable effects of the spirit infused by his lordship into the royal mind was, the rescuing of the majestic mind of Johnson from the distresses of a dependence on letters for subsistence; a transaction, for which many bosoms, yet to be animated with the breath of life, will expand in gratitude at the mentlon of the name of George III.

The ministerial character of lord Bute has been thus drawn by an impartial writer: "Few ministers have been more hated than lord Bute was by the English nation; yet, if we estimate his conduct from facts, without being influenced by local or temporary prejudices, we can by no means find just grounds for the odium which he incurred. As a war minister, though his plans discovered little of original genius, and naturally proceeded from the measures of his predecessor, the general state of our resources, the conquests achieved, and the dispositions of our fleets and armies, yet they were judicious; the agents appointed to carry them on were selected with discernment, and the whole result was successful. His desire of peace, after so long and burdensome a war, was laudable, but perhaps too eagerly manifested. As a negotiator, he did not procure the best terms, which, from our superiority, might have been obtained. His project of finance, in itself unobjectionable, derived its impolicy from the unpopularity of his administration. Exposed from unfounded prejudices to calumny, he deserved and earned dislike by his haughty deportment. The manners which custom might have sanctioned from an imperious chieftain to his servile retainers in a remote corner of the island, did not suit the independent spirit of the English metropolis. The respectable mediocrity of his talents, suitable attainments, and his decent moral character, deserved an esteem which his manners precluded. Since he could not, like Pitt, command genius, he ought, like the duke of Newcastle, to have conciliated by affable demeanour. His partizans have praised the tenacity of lord Bute in his purposes; a quality which, guided by wisdom in the pursuit of right, and combined with the power to render success ultimately probable, is magnanimous but, without these requisites, is stubborn obstinacy. No charge has been more frequently made against lord Bute, than that he was a promoter of arbitrary principles and measures. This is an accusation for which its supporters can find no grounds in his particular acts; they endeavoured therefore to establish their assertion by circuitous arguments. Lord Bute had been the means of dispossessing the Whig connection of power, and had given Scotsmen appointments which were formerly held by the friends of the duke of Newcastle. To an impartial investigation, however, it appears evident, that lord Bute preferred himself as minister to the duke of Newcastle. If we examine his particular nominations, we shall find that he neither exalted the friends of liberty nor despotism, but his own friends. It would probably have been better for the country if lord Bute had never been minister; but all the evils that may be traced to that period did not necessarily proceed from his measures, as many of them flowed from circumstances over which he had no control. Candour must allow that the comprehensive principle on which his majesty resolved to govern was liberal and meritorious, though patriotism may regret that he was not more successful in his first choice. The administration of Bute teaches an instructive lesson, that no man can be long an effectual minister of this country, who will not occasionally attend, not only to the well-founded judgment, but also to the prejudices, of Englishmen."

The earl of Bute spent the most of the remainder of his life in retirement, at his seat of Luton in Bedfordshire, but not without the suspicion of still maintaining a secret influence over the royal counsels. "The spirit of the Favourite," says Junius, "had some apparent influence over every administration; and every set of ministers preserved an appearance of duration, as long as they submitted to that influence." The chief employment, however, of the ex-minister was the cultivation of literature and science. He was more fond of books of information than of imagination. His favourite study was botany, with which he acquainted himself to such an extent, that the first botanists in Europe were in the habit of consulting his lordship. He composed a work on English plants, in nine quarto volumes, of which only sixteen copies were thrown off; the text as well as the figures of the plants being engraved on copper-plates, and these plates, it is said, immediately cancelled, though the work cost upwards of one thousand pounds. He presented to the Winchester college a bronze statue of their founder, William of Wykham, supposed to have been the work of some great artist in the fourteenth century. It is a full figure in the episcopal habit, sixteen inches high, and executed with remarkable elegance. His lordship was elected one of the trustees of the British Museum in 1765, held the office of chancellor of the Marischal college and, on the institution of the Society of Antiquaries in Scotland (1780) was elected president. He was an honorary fellow of the Royal College of Physicians at Edinburgh, and to him the university of that city was indebted for its useful appendage, the Botanic Garden.