This impressive portrait, which expresses so clearly the keen intellect and physical frailty of the sitter has descended through the family of Robert Boyle's kinsmen, the Earls of Shannon. It is of a type produced by Johann Kerseboom after a sitting in 1689, noted in a letter of Samuel Pepys to his friend John Evelyn.1 The Shannon portrait is an autograph version by Kerseboom from this sitting and demonstrates fully the artist's painterly quality in the handling of the draperies and fabrics as well as in the striking flesh tones.

Collins-Baker in his seminal work on the history of seventeenth century British portraiture, Lely and the Stuart Portrait Painters (speaking of the version in the collection of the Royal Society, which with this example is the only other version presently believed to be by the hand of Kerseboom himself) remarks that the portrait is ''a work of eminently respectable quality. The somewhat ascetic, melancholy temper of this portrait, and the curiously absent-minded look in the head, are marked characteristics that I have found in the work of no other painter.''2 He notes also the ''musing introspective look that gives us the impression that the sitter has fallen into some reverie, all oblivious of the business in hand''3

The likeness preserved by Kerseboom accords well with descriptions of Boyle in the writings of contemporaries. A debilitating illness at the age of twenty-one left him infirm for the rest of his life, and his appearance was notably pallid and emaciated. He pursued his scientific enquiries to the detriment of his health, and a more robust constitution than his could not have borne prolonged contact with mercury and other noxious elements without harm. By 1689, the year of this portrait, Boyle's state was such that he suspended his attendance at meetings of the Royal Society and declined to receive visitors for four days out of each week. He did not give up his research, however, and, indeed, was tempted to do so only by the one faculty that had alarmed him throughout his life, his exceedingly poor memory.

At the time of Boyle's death in 1691 the disposal of his effects fell to his executors, Richard Earl of Burlington, John Warr and Sir Henry Ashurst. Portraits of Boyle from the Kerseboom sitting were distributed to institutions associated with Robert Boyle, as well as to members of the immediate family. The executors presented an autograph version to the Royal Society in 16924, and a copy was given to the Boyle School Yetminster, a charitable foundation. Both Burlington and Sir Henry possessed a version of the portrait, these now being in the collections of the College of William and Mary, Williamsburg, Va. and the National Portrait Gallery, London, respectively. Both are considered studio copies. A further version, which may have been autograph but is now lost, is recorded by George Vertue in the collection Richard Lord Burlington, grandson of the executor, in 1727.5

It is most probable that the Shannon portrait of Robert Boyle was presented by Lord Burlington to his nephew, Colonel the Hon. Henry Boyle, son of his brother Charles Earl of Orrery, as a part of these donations. Colonel Boyle died shortly afterwards in 1693 whilst on active service in Europe, when he was succeeded by his son Henry. Henry Boyle entered into politics and became a shrewd and accomplished power-broker in Irish and English affairs, filling the offices of Speaker of the Irish Parliament and Lord Chief Justice of Ireland. For these achievements he was raised to the peerage as Earl of Shannon, and it is in the family of the Earls of Shannon that this portrait has remained.

Robert Boyle was born in 1627, the seventh son of Richard Boyle, the first and ''great'' Earl of Cork, and the great-uncle of Henry first Earl of Shannon. At the age of eight Boyle went to Eton and studied there for four years before moving to his father's new estate at Stalbridge, Dorsetshire, where his education was continued by private tutors. In 1638 he and his eldest brother Francis began a Grand Tour of Europe, spending several years in Switzerland and Italy -where he was exposed to the ''new paradoxes of the star-gazer Galileo'' before finally returning in 1644 to an England in the throes of Civil War. Boyle spent much of the next four years engaged in experimental enquiries and, after visiting his Irish estates in 1652-3, returned to settle in Oxford in the society of many of his former philosophical associates.

There he continued his investigations, including physiological and physical experiments with an air pump constructed for him by Robert Hooke. Simultaneously he improved his knowledge of foreign languages and wrote several moral and philosophical essays.

In 1668 he went to reside in London, where he continued to produce a steady flow of scientific and religious writings which brought him an immense reputation both at home and abroad. Among Boyle's numerous correspondents were Newton, Locke, Aubrey, Evelyn, Oldenburg, Wallis and Hartlib. He took a most active and influential part in the establishment of the Royal Society, was a member of its first Council named in the first Royal Charter and was elected its third President on 30th November 1680 but declined to serve. As a powerful advocate of experimental method and mechanical atomism he left his mark on his contemporaries and subsequent generations. He is probably best known for his formulation of Boyle's Law. He died on 30th December 1691 and was buried eight days later in St Martin in the Fields, Westminster.

We are grateful to Tabitha Barber of the Tate Gallery, London, for confirming the attribution to Johann Kerseboom.

(1) ''The most excellent Mr Boyle… has newly been prevailed with by Dr King [Sir Edmund King (1629-1709) FRS Robert Boyle''s Physician] to have his head taken by one of much less name than Mr Kneller, and a stranger, one Causabon [i.e. Kerseboom]'' Diary and Correspondence of John Evelyn, FRS, edited by William Bray, 4 vols. London 1854, vol. iii, p312. This apparent dismissal of Kerseboom deserves explanation. Both Pepys and Evelyn were patrons -and, clearly, partisans- of Sir Godfrey Kneller (1646-1723), who had been established in London for nearly fifteen years by the date of this sitting in 1689. Kerseboom was a much more recent arrival, having reached London with his father (or uncle?) Frederick in the early 1680s. The portrait of Robert Boyle remains one of earliest dated works, but also his most striking in composition and accomplished in characterisation. Had Pepys and Evelyn been aware of Kerseboom's insightful full-length Portrait of Edward Russell 5th Earl of Bedford dated to c.1685 they would have been more conscious of his merits. Kerseboom went on to enjoy a fashionable practice; his greatest prominence was to come in the period c.1694-1705, when he painted a series of Admirals, including a Portrait of John Lord Berkeley.

(2) C. H. Collins Baker Lely and the Stuart Portrait Painters, London, 1912, Vol. II, p. 50.

(3) Ibid.

(4) Journal Book of the Royal Society, viii, 1690-1696 records: ''The President was desired to Return the Societie's Thanks to the Executors of Mr Boyle for their Present of Mr Boyle's picture this Day presented.''

(5) Walpole Society, 1932, XX p39 Vertue Note Books.