The re-cataloguing of the Royal Society's collection of oil paintings has thrown up some interesting questions about works of art no longer in the Society's care, and in particular the whereabouts of at least four (or possibly five) 'missing' pictures that were very early acquisitions and that formed an important display element in the organization's houses at Gresham College and Crane Court during the Society's first century of activity. Although all of these works must have been painted in the seventeenth century, only two were donated then: a further two were eighteenth-century acquisitions. This last pair survived into the nineteenth century before disappearing from the occasional catalogues produced by the Society. What were they and what happened to them? Milo Keynes's excellent short paper on the Society's picture of William Harvey (1578-1657) attributes the work now in Carlton House Terrace to a copyist after a lost original by Sir Peter Lely (1618-80) and argues that it was in the Society's custody from 1683. 1 The donation was by John Mappletoft FRS (1631-1721), and there is some clear evidence to support this within the Society's minutes, which state that 'Dr Mapletoft presented the Picture of Dr. Wm. Harvey; for which Mr. Hill was desired to return him the thanks of the Company.' 2 The association of the painting and donor is recorded in the first list of artworks printed by the Royal Society in 1834. 3 However, there is a slight complicating element to this story, not dealt with by Keynes. A minute of 1696 records that 'Mr. Povey presented the Society with the picture of the fam'd Dr. Harvey and Mr. Buchanan, both of wch. were order'd to be hung in the Society's meeting room.' This implies that a second Harvey portrait was gifted to the Society by Thomas Povey FRS (ca. 1615ca. 1702) and that in common with the accompanying likeness of George Buchanan (1506-82) it was an oil painting rather than a print. Keynes's main argument is unaffected (that the Royal Society's surviving Harvey portrait has a seventeenth-century provenance), but there now seems to be an element of uncertainty as to which donor originally owned the image. Oddly, although Keynes cited a list of the Society's pictures compiled by the eighteenth-century engraver George Vertue (1684-1756) in 1737 within his article, he seems to have missed the second portrait (it is there as 'ditto', after the first). 4 If confirmation of the nature of the additional work were needed, a later piece describing the Society's paintings from The Gentleman's Magazine lists two Harvey portraits as late as 1768, 5 one on the staircase at Crane Court, the other in the meeting room. The anonymous writer distinguishes between original pictures, busts and prints, confirming the medium of both works as oils. No clue as to the appearance of the *