BOYLE, ROBERT English natural philosopher, seventh son and 14th child of Richard Boyle, the great earl of Cork, was born at Lismore castle, Ireland, Jan. 25 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. In 1638 he went to travel abroad with a French tutor. Visiting Italy in 1645, he re mained during the winter of that year in Florence, studying the "paradoxes of the great star-gazer" Galileo. On returning to Eng land in 1644 Boyle 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 culti vation of the "new philosophy." They met often in London, at Gresham college ; some of the members also had meetings at Ox ford, and in that city Boyle went to reside in 16S4. Reading in 1657 of Otto von Guericke's air-pump, he set himself with the assistance of Robert Hooke to devise improvements in its con struction, and with the result, the "machina Boyleana" or "pneu matical engine," finished in 1659, he began a series of experiments on the properties of air. An account of the work was published in 1660 as New Experiments Physico-Meclianical 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 answer ing 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 5676. 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 presi dent of the society, but declined the honour from a scruple about oaths. In 1668 he moved to London, where he died on Dec. 3o, 1691.
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. He himself performed experiments in the hope of effecting the transmutation of metals, and he was instrumental in obtaining the repeal, in 5689, 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 propa gation 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, etc.—chem istry 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." He advanced towards the view that matter was ultimately composed of "corpuscles" of various sorts and sizes capable of arranging themselves into groups, and that each group constituted a chemical substance. He distinguished between mixtures and compounds, and showed that a compound might have different qualities from those of its constituents. He 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.
Besides being a busy natural philosopher, Boyle was interested in theology, and in 1665 would have received the provostship of Eton, if he had taken orders. He learned Hebrew, Greek and Syriac in order to pursue his scriptural studies, and spent large sums on Biblical translations. 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.
BIBLIOGRAPHY.--The following are the more important of his works Bibliography.--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) ; Hydrostatical Paradoxes (1666) , Origin of Forms and Qualities accord ing to the Corpuscular Philosophy (i666) , a continuation of his work on the spring of air (1669) ; Experiments and Notes about the Mechan ical Origin or Production of Particular Qualities, including notes on electricity and magnetism (1676) ; Memoirs for the Natural History of the Human Blood (1684) ; Short Memoirs for the Natural Experi mental History of Mineral Waters (5685); Medicina Hydrostatica (1690) ; and Experimenta et Observationes Physicae (1691) . His other writings include Occasional Reflections upon Several Subjects (1665), which was ridiculed by Swift in A Pious Meditation upon a Broom stick, and by Butler in An Occasional Reflection on Dr. Carlton's Feel ing a Dog's Pulse at Gresham College; Excellence of Theology cons pared with Natural Philosophy (1664) ; 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 (169o) . 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 (1692-98) ; and A Free Discourse against Customary Swearing (1695). An incomplete and unauthorized edition of Boyle's works was pub lished 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 5772 in six volumes, quarto. Boyle bequeathed his natural history collections to the Royal Society, which also possesses a portrait of him by the German painter, Friedrich Kerse boom (5632-9o). See F. Masson, Robert Boyle, a Biography (1914) .