BOYLE, ROBERT (1627–1691), English natural philosopher, seventh son and fourteenth child of Richard Boyle, the great earl of Cork, was born at Lismore Castle, in the province of Munster, Ireland, on the 25th of January 1627. While still a child he learned to speak Latin and French, and he was only eight years old when he was sent to Eton, of which his father’s friend, Sir Henry Wotton, was then provost. After spending over three years at the college, he went to travel abroad with a French tutor. Nearly two years were passed in Geneva; visiting Italy in 1641, he remained during the winter of that year in Florence, studying the “paradoxes of the great star-gazer” Galileo, who died within a league of the city early in 1642. Returning to England in 1644 he found that his father was dead and had left him the manor of Stalbridge in Dorsetshire, together with estates in Ireland. From that time he gave up his life to study and scientific research, and soon took a prominent place in the band of inquirers, known as the “Invisible College,” who devoted themselves to the cultivation of the “new philosophy.” They met frequently in London, often at Gresham College; some of the members also had meetings at Oxford, and in that city Boyle went to reside in 1654. Reading in 1657 of Otto von Guericke’s air-pump, he set himself with the assistance of Robert Hooke to devise improvements in its construction, and with the result, the “machina Boyleana” or “Pneumatical Engine,” finished in 1659, he began a series of experiments on the properties of air. An account of the work he did with this instrument was published in 1660 under the title New Experiments Physico-Mechanical touching the spring of air and its effects. Among the critics of the views put forward in this book was a Jesuit, Franciscus Linus (1595–1675), and it was while answering his objections that Boyle enunciated the law that the volume of a gas varies inversely as the pressure, which among English-speaking peoples is usually called after his name, though on the continent of Europe it is attributed to E. Mariotte, who did not publish it till 1676. In 1663 the “Invisible College” became the “Royal Society of London for improving natural knowledge,” and the charter of incorporation granted by Charles II. named Boyle a member of the council. In 1680 he was elected president of the society, but declined the honour from a scruple about oaths. In 1668 he left Oxford for London where he resided at the house of his sister, Lady Ranelagh, in Pall Mall. About 1689 his health, never very strong, began to fail seriously and he gradually withdrew from his public engagements, ceasing his communications to the Royal Society, and advertising his desire to be excused from receiving guests, “unless upon occasions very extraordinary,” on Tuesday and Friday forenoon, and Wednesday and Saturday afternoon. In the leisure thus gained he wished to “recruit his spirits, range his papers,” and prepare some important chemical investigations which he proposed to leave “as a kind of Hermetic legacy to the studious disciples of that art,” but of which he did not make known the nature. His health became still worse in 1691, and his death occurred on the 30th of December of that year, just a week after that of the sister with whom he had lived for more than twenty years. He was buried in the churchyard of St Martin’s in the Fields, his funeral sermon being preached by his friend Bishop Burnet.
Boyle’s great merit as a scientific investigator is that he carried out the principles which Bacon preached in the Novum Organum. Yet he would not avow himself a follower of Bacon or indeed of any other teacher: on several occasions he mentions that in order to keep his judgment as unprepossessed as might be with any of the modern theories of philosophy, till he was “provided of experiments” to help him judge of them, he refrained from any study of the Atomical and the Cartesian systems, and even of the Novum Organum itself, though he admits to “transiently consulting” them about a few particulars. Nothing was more alien to his mental temperament than the spinning of hypotheses. He regarded the acquisition of knowledge as an end in itself, and in consequence he gained a wider outlook on the aims of scientific inquiry than had been enjoyed by his predecessors for many centuries. This, however, did not mean that he paid no attention to the practical application of science nor that he despised knowledge which tended to use. He himself was an alchemist; and believing the transmutation of metals to be a possibility, he carried out experiments in the hope of effecting it; and he was instrumental in obtaining the repeal, in 1689, of the statute of Henry IV. against multiplying gold and silver. With all the important work he accomplished in physics—the enunciation of Boyle’s law, the discovery of the part taken by air in the propagation of sound, and investigations on the expansive force of freezing water, on specific gravities and refractive powers, on crystals, on electricity, on colour, on hydrostatics, &c.—chemistry was his peculiar and favourite study. His first book on the subject was The Sceptical Chemist, published in 1661, in which he criticized the “experiments whereby vulgar Spagyrists are wont to endeavour to evince their Salt, Sulphur and Mercury to be the true Principles of Things.” For him chemistry was the science of the composition of substances, not merely an adjunct to the arts of the alchemist or the physician. He advanced towards the modern view of elements as the undecomposable constituents of material bodies; and understanding the distinction between mixtures and compounds, he made considerable progress in the technique of detecting their ingredients, a process which he designated by the term “analysis.” He further supposed that the elements were ultimately composed of particles of various sorts and sizes, into which, however, they were not to be resolved in any known way. Applied chemistry had to thank him for improved methods and for an extended knowledge of individual substances. He also studied the chemistry of combustion and of respiration, and made experiments in physiology, where, however, he was hampered by the “tenderness of his nature” which kept him from anatomical dissections, especially of living animals, though he knew them to be “most instructing.”
Besides being a busy natural philosopher, Boyle devoted much time to theology, showing a very decided leaning to the practical side and an indifference to controversial polemics. At the Restoration he was favourably received at court, and in 1665 would have received the provostship of Eton, if he would have taken orders; but this he refused to do, on the ground that his writings on religious subjects would have greater weight coming from a layman than a paid minister of the Church. He spent large sums in promoting the spread of Christianity, contributing liberally to missionary societies, and to the expenses of translating the Bible or portions of it into various languages. By his will he founded the Boyle lectures, for proving the Christian religion against “notorious infidels, viz. atheists, theists, pagans, Jews and Mahommedans,” with the proviso that controversies between Christians were not to be mentioned.
In person Boyle was tall, slender and of a pale countenance. His constitution was far from robust, and throughout his life he suffered from feeble health and low spirits. While his scientific work procured him an extraordinary reputation among his contemporaries, his private character and virtues, the charm of his social manners, his wit and powers of conversation, endeared him to a large circle of personal friends. He was never married. His writings are exceedingly voluminous, and his style is clear and straightforward, though undeniably prolix.
The following are the more important of his works in addition to the two already mentioned:—Considerations touching the Usefulness of Experimental Natural Philosophy (1663), followed by a second part in 1671; Experiments and Considerations upon Colours, with Observations on a Diamond that Shines in the Dark (1663); New Experiments and Observations upon Cold (1665); Hydrostatical Paradoxes (1666); Origin of Forms and Qualities according to the Corpuscular Philosophy (1666); a continuation of his work on the spring of air (1669); tracts about the Cosmical Qualities of Things, the Temperature of the Subterraneal and Submarine Regions, the Bottom of the Sea, &c. with an Introduction to the History of Particular Qualities (1670); Origin and Virtues of Gems (1672); Essays of the strange Subtilty, great Efficacy, determinate Nature of Effluviums (1673); two volumes of tracts on the Saltness of the Sea, the Hidden Qualities of the Air, Cold, Celestial Magnets, Animadversions on Hobbes’s Problemata de Vacuo (1674); Experiments and Notes about the Mechanical Origin or Production of Particular Qualities, including some notes on electricity and magnetism (1676); Observations upon an artificial Substance that Shines without any Preceding Illustration (1678); the Aerial Noctiluca (1680); New Experiments and Observations upon the Icy Noctiluca (1682); a further continuation of his work on the air; Memoirs for the Natural History of the Human Blood (1684); Short Memoirs for the Natural Experimental History of Mineral Waters (1685); Medicina Hydrostatica (1690); and Experimenta et Observiationes Physicae (1691). Among his religious and philosophical writings were:—Seraphic Love, written in 1648, but not published till 1660; an Essay upon the Style of the Holy Scriptures (1663); Occasional Reflections upon Several Subjects (1665), which was ridiculed by Swift in A Pious Meditation upon a Broomstick, and by Butler in An Occasional Reflection on Dr Charlton’s Feeling a Dog’s Pulse at Gresham College; Excellence of Theology compared with Natural Philosophy (1664); Some Considerations about the Reconcileableness of Reason and Religion, with a Discourse about the Possibility of the Resurrection (1675); Discourse of Things above Reason (1681); High Veneration Man owes to God (1685); A Free Inquiry into the vulgarly received Notion of Nature (1686); and the Christian Virtuoso (1690). Several other works appeared after his death, among them The General History of the Air designed and begun (1692); a “collection of choice remedies,” Medicinal Experiments (1692–1698); and A Free Discourse against Customary Swearing (1695). An incomplete and unauthorized edition of Boyle’s works was published at Geneva in 1677, but the first complete edition was that of Thomas Birch, with a life, published in 1744, in five folio volumes, a second edition appearing in 1772 in six volumes, 4to. Boyle bequeathed his natural history collections to the Royal Society, which also possesses a portrait of him by the German painter, Friedrich Kerseboom (1632–1690).