Although the volume of the surviving papers of Robert Boyle is substantial (over 20,000 leaves), a considerable amount of the written material left by Boyle at his death in 1691 has not survived in the Boyle archive. This paper gauges the scale and identity of these losses using the surviving inventories made by the Rev. Henry Miles in the 1740s when he was collecting and sorting Boyle's literary remains in conjunction with Thomas Birch's preparation of his 1744 Life and Works (...) of Boyle. These detailed lists (edited as appendices to this paper), together with other sources, indicate losses due to a variety of reasons, some deliberate, others accidental. The losses involved the disposal of both items judged (in the eighteenth century) to be peripheral to Boyle's archive and, ironically, those in the most finished state from Boyle's hand, which were perhaps abortively destined for the Birch edition. These losses have significantly altered the character of the Boyle Papers, and thus the view of Boyle that is derived from them. (shrink)