<p style='text-align: justify;'>Cambridge, Trinity College, MS O.8.31 (hereafter Trinity MS O.8.31) is a composite manuscript that contains a compilation of popular scientific treatises on subjects at the intersection of medicine and the astronomical and astrological sciences. Comprising five main parts of varying date and place of origin, the manuscript was almost certainly bound in its present form by the third quarter of the 15th century, since it was once owned or used by Roger Marchall (c. 1417-1477), a doctor and physician to Edward IV. Marchall added a table of contents on f. <a href='' onclick='store.loadPage(12);return false;'>iii verso</a> (that given on f. <a href='' onclick='store.loadPage(9);return false;'>ii recto</a> does not relate to this manuscript, but to another lost or unidentified volume) and inserted rubrics to some of these treatises where they appear in the manuscript. Texts matching the descriptions given by Marchall are to be found in four of the five central Parts (nos 2-3 and 5-6), confirming that none of these is a later addition to the manuscript, though there are some differences in attribution. For instance, the first and third texts in the table correspond to the first and third texts in Part 2, the <i>Chirurgia</i> of Henri de Mondeville (ff. <a href='' onclick='store.loadPage(13);return false;'>1r-63v</a>) and the recipes from surgical treatises by Roger and Roland of Salerno (ff. <a href='' onclick='store.loadPage(223);return false;'>106r-108r</a>). The text that sits between them, however, is described by Marchall as a 'Tractatus aquarum' and attributed to Petrus Hispanus, but as an 'Antidotarius' by Henri de Mondeville in the scribal rubric that marks its beginning (f. <a href='' onclick='store.loadPage(141);return false;'>65r</a>).</p><p style='text-align: justify;'>Further disparities between the table of contents and what follows suggests that the manuscript has been subject to some rearrangement, part of it at least at Marchall's hands. None of the texts in Part 4 is listed in Marchall's table of contents, but these five quires must have been in his possession, since two of the texts are prefaced by rubrics written by his hand (see ff. <a href='' onclick='store.loadPage(276);return false;'>132v</a> and <a href='' onclick='store.loadPage(279);return false;'>134r</a>). Notably, one of the two recipes in this Part for 'metheglyn', a spiced or medicated variety of mead, is written in Middle English; Marchall's manuscripts typically contain texts written only in Latin. Part 4 is preceded not by the deontological text Marchall described as 'De gestu medici erga infirmum' ('On the conduct of a doctor towards the patient'), which is not found in the volume, but by the text he listed last in his table: '8. Anothomia Magistri Ricardi' (ff. <a href='' onclick='store.loadPage(237);return false;'>113r-118v</a>).</p><p style='text-align: justify;'>Each Part of Trinity MS O.8.31 is written on paper and, as is sometimes found in books of this period, the quires have been reinforced by sewing guards: strips of parchment placed along the spinefold around the back and at the centre of each quire. It is often the case, as here, that these strips have been recycled from one or more manuscripts (usually documents), and occasionally enough of the text may be read to afford some clues as to the general location of the manuscript's binding and thus likely provenance (see <a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-DD-00005-00053/1'>Cambridge, University Library, MS Dd.5.53</a>, for example). Unfortunately, for this manuscript, the sewing guards were cut vertically from their source, so only a couple of letters of a minute textualis bookhand are visible (see, for example, the image of f. <a href='' onclick='store.loadPage(21);return false;'>5r</a>). Nevertheless, the source manuscript appears to have contained works of a scientific nature, since several of the guard strips bear brief sequences of medieval Hindu-Arabic numerals. Owing to the condition of the binding, and the narrowness of each guard, it has not been possible to digitise these elements. </p><p style='text-align: justify;'>Roger Marchall's ownership or use of manuscripts is very well-attested, with forty-five surviving books (including this one) bearing evidence to connect him to them in some way; six others may have been his or accessed by him, and a further twelve are recorded but not traced. Thirteen manuscripts owned or used by Marchall (and another with possible Marchall connections) have been digitised, catalogued and conserved as part of the <a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/collections/medievalmedicalrecipes'><i>Curious Cures in Cambridge Libraries</i></a> project: <ul><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-GONVILLE-AND-CAIUS-00059-00153/1'>Cambridge, Gonville and Caius College, MS 59/153</a> (Voigts (1995), no. 2) </li><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-GONVILLE-AND-CAIUS-00098-00050/1'>Cambridge, Gonville and Caius College, MS 98/50</a> (Voigts (1995), no. 4) </li><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-GONVILLE-AND-CAIUS-00105-00057/1'>Cambridge, Gonville and Caius College, MS 105/57</a> (Voigts (1995), no. 5)</li><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-GONVILLE-AND-CAIUS-00159-00209/1'>Cambridge, Gonville and Caius College, MS 159/209</a> (Voigts (1995), no. 9)</li><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-GONVILLE-AND-CAIUS-00178-00211/1'>Cambridge, Gonville and Caius College, MS 178/211</a> (Voigts (1995), no. 10)</li><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-GONVILLE-AND-CAIUS-00181-00214/1'>Cambridge, Gonville and Caius College, MS 181/214</a> (Voigts (1995), no. 11)</li><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-GONVILLE-AND-CAIUS-00345-00620/1'>Cambridge, Gonville and Caius College, MS 345/620</a> (Voigts (1995), no. 12)</li><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-GONVILLE-AND-CAIUS-00373-00593/1'>Cambridge, Gonville and Caius College, MS 373/593</a> (Voigts (1995), no. 13)</li><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-GONVILLE-AND-CAIUS-00379-00599/1'>Cambridge, Gonville and Caius College, MS 379/599</a> (Voigts (1995), no. 14)</li><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-GONVILLE-AND-CAIUS-00401-00623/1'>Cambridge, Gonville and Caius College, MS 401/623</a> (Voigts (1995), no. 16)</li><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-PETERHOUSE-00095/1'>Cambridge, Peterhouse, MS 95</a> (Voigts (1995), no. 24)</li><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-PETERHOUSE-00222/1'>Cambridge, Peterhouse, MS 222</a> (Voigts (1995), no. 28)</li><li><a target='_blank' class='externalLink' href='https://mss-cat.trin.cam.ac.uk/Manuscript/O.8.31'>Cambridge, Trinity College, MS O.8.31</a> (Voigts (1995), no. 29)</li><li><a target='_blank' class='externalLink' href='https://cudl.lib.cam.ac.uk/view/MS-ADD-09213/1'>Cambridge, University Library, MS Add. 9213</a> (possible Marchall connections) (Voigts (1995), no. 48)</li></ul></p><p style='text-align: justify;'>Dr Sarah Gilbert<br /> Curious Cures in Cambridge Libraries Project Cataloguer<br /> Cambridge University Library<br /> and<br /> Dr James Freeman<br /> Medieval Manuscripts Specialist<br /> Cambridge University Library</p><p style='text-align: justify;'><b>References</b>: <div style='list-style-type: disc;'><div style='display: list-item; margin-left: 20px;'>L. Voigts, 'A doctor and his books: the manuscripts of Roger Marchall (d. 1477)', in R. Beadle and A. J. Piper (eds.), <i>New science out of old books: studies in manuscripts and early printed books in honour of A.I. Doyle</i> (Aldershot, 1995) pp. 249-314</div></div><br /></p>