ment about the loss of many of his Writings,' published in May 1688, in which he described the various mischances, both by fraud and accident, having befallen them, and declared his intention to write thenceforth on loose sheets, as offering less temptation to thieves than bulky packets, and to send to press without the dangerous delays of prolonged revision. In the same year he gave to the world 'A Disquisition concerning the Final Causes of Natural Things,' and in 1690 'Medicina Hydrostatica ' and 'The Christian Virtuoso,' setting forth the mutual serviceableness of science and religion. The last work published by himself was entitled 'Experimenta et Observationes Physicae,' part i. (1691); the second part never appeared.
In 1689 the failing state of his health compelled him to suspend communications to the Royal Society, and to resign his post, filled since 1661, as governor of the Corporation for the Spread of the Gospel in New England. About the same time he publicly notified his intention of excluding visitors on certain portions of four days in each week, thus reserving leisure to 'recruit' (as he said) 'his spirits, to range his papers, and to take some care of his affairs in Ireland, which are very much disordered, and have their face often changed by the public calamities there.' He was also desirous to complete a collection of elaborate chemical processes, which he is said to have entrusted to a friend as 'a kind of Hermetick legacy,' but which were never made known. Some secrets discovered by him, such as the preparation of subtle poisons and of a liquid for discharging writing, he concealed as mischievous.
From the age of twenty-one he had suffered from a torturing malady, of which he dreaded the aggravation, with the approach of death, beyond his powers of patient endurance. But his end was without pain, and almost without serious illness. His beloved sister, Catherine Lady Ranelagh, a conspicuous and noble personage, died 23 Dec. 1691. He survived her one week, expiring three-quarters of an hour after midnight, 30 Dec., aged nearly 65, and was buried 7 Jan. 1692 in St. Martin's-in-the-Fields, Westminster. Dr. Burnet preached his funeral sermon. By his will he founded and endowed with 50l. a year the 'Boyle Lectures,' for the defence of Christianity against unbelievers, of which the first set of eight discourses was preached by Bentley in 1692.
'Mr. Boyle,' Dr. Birch writes (Life, p. 86), 'was tall of stature, but slender, and his countenance pale and emaciated. His constitution was so tender and delicate that he had divers sorts of cloaks to put on when he went abroad, according to the temperature of the air, and in this he governed himself by his thermometer. He escaped, indeed, the small-pox during his life, but for almost forty years he laboured under such a feebleness of body and lowness of strength and spirits that it was astonishing how he could read, meditate, try experiments, and write as he did. He had likewise a weakness in his eyes, which made him very tender of them, and extremely apprehensive of such distempers as might affect them.' To these disabilities was added that of a memory so treacherous (by his own account) that he was often tempted to abandon study in despair. He spoke with a slight hesitation; nevertheless at times 'distinguished himself by so copious and lively a flow of wit that Mr. Cowley and Sir William Davenant both thought him equal in that respect to the most celebrated geniuses of that age.' He never married, but Evelyn was credibly informed that he had paid court in his youth to the Earl of Monmouth's beautiful daughter, and that his passion inspired the essay on 'Seraphic Love,' published in 1660. It was, however, already written in 1648, and Boyle himself assures us, 6 Aug. of that year, that he 'hath never yet been hurt by Cupid' (Works, i. 155). The story is thus certainly apocryphal.
The tenor of his life was in no way inconsistent with his professions of piety. It was simple and unpretending, stainless yet not austere, humble without affectation. His temper, naturally choleric, he gradually subdued to mildness; his religious principles were equally removed from laxity and intolerance, and he was a declared foe to persecution. He shared, indeed, in some degree the credulousness of his age. He publicly subscribed to the truth of the stories about the 'demon of Mascon,' and vouched for the spurious cures of Greatrakes the 'stroker.' Nor did he wholly escape the narrowness inseparable from the cultivation of a philosophy 'that valued no knowledge but as it had a tendency to use.' His view of astronomical studies is, in this respect, characteristic. If the planets have no physical influence on the earth, he admits his inability to propound any end for the pains bestowed upon them; 'we know them only to know them' (ibid. v. 124). Yet his services to science were unique. The condition of his birth, the elevation of his character, the unflagging enthusiasm of his researches, combined to lend dignity and currency to their results. These were coextensive with the whole range, then accessible, of experimental investigation. He personified, it might be said, in a manner at once
