The manuscript was written by Feargus Ó Caiside in the house of Énrigh Ó Caiside, perhaps at a place called Faithche Caorach in County Monaghan or Fermanagh (folio 4 recto, column a, line 34; cf. “Éigse”, volume 2, page 165). His hand is simple, small and neat. The sole marginalium, ‘amen’, (folio 4 recto), may be by another hand. Due to the illegibility of folio 4 verso through staining and rubbing, the account of it below is in some respects tentative.

With the manuscript is a letter, 1 folio, of Thomas E Cassidy, New Rochelle, New York, to the Curator of the Advocates Library, dated 4th July 1921, on the subject of a later Fergus O Cassidy and his descendants.

The contents (text) are as follows.

(i) On Aphorisms of Hippocrates, cf. Adv.MS.72.1.10, folio 1 recto, column a, line 37. Beginning "In acutis morbis frigidtas extremitatum malum est edhon tindscainter ann so an .vii. p[air]t[igeal] d' Amporismorum". Last section beginning 'Sia febris habito tumore non existente'. Ends folio 4 recto, column a, line 34 'is mar sin leighistear an n[eas]c[oid] darub ainm sgi[nannsia] mail[e] [re] grasaib Dia ⁊ na healadhna. Finit. Amen. Feargus O Caisidi do sgrib so a tig Enrigh I Caisidi ei[ar] faithchi caer[ach] Satharn roim la Lunusa ⁊rl-' (cf. Adv.MS.18.2.11, folio 170 verso, column a, bottom of page). Represents book 7, numbers 1-60. Also covered by Adv.MS.72.2.10, pages 1-56 (abridged version) and Adv.MS.18.2.11, folios 140-170. Authorities cited: Galen, Gilbertinus (G.b., folio 1 verso, column a, last line; folio 2 verso, column a, line 19; Gill., folio 1 verso, column b, line 18), Constantinus (folio 1 verso, column b, line 17), Avicenna, Theophilus (folio 2 recto, column b, bottom of the page), Martinus (folio 3 verso, column a, line 40), Rogerus (folio 4 recto, column a, line 18). (Folio 1 recto, column a, line 1.)

(ii) On crisis. Beginning 'Fiarf[ai]gter ann so, an gluasacht oband gluasacht an faet[ai]gti?' Ends 'gurab do ainmnigter an faeth[ugud]'. Authorities cited: Galen, Hippocrates, Avicenna. (Folio 4 recto, column a, line 38.)

(iii) On the four causes in Aristotelian logic. Beginning 'Scire est rem per quasum cognocire et cetera .i. as aml[aid] adeir an Feallsam'. Ends '⁊ fadeoigh an cuis crichnaidhteach'. (Folio 4 recto, column a, line 54.)

(iv) Lanfranc's teaching on diet. Beginning 'Langfrangcus adeir na briatra so sis'. (Folio 4 recto, column b, line 13.)

(v) On imposthumes. Beginning 'Fiarf[ai]gter ann so, an easl[aint]i a neasgoid?' Ends '⁊ gailar continoideach. Finit'. Authorities cited: Galen, Avicenna, Constantinus. (Folio 4 recto, column b, line 19.)

(vi) On the voice and on coughing. Beginning 'Et as[ed] as guth and gnim rouasal toileam[ail]'. Ends 'aderur an cosachtach'. Galen cited. (Folio 4 recto, column b, line 39.)

(vii) On hiccupping. Beginning 'Singultus adhon in fail'. (Folio 4 verso, column a, line 3.)

(viii) On the stomach. Beginning 'As[ed] as gaile ann dor[eir] G[alien] a l[eabar] Consantin don gaile'. (Folio 4 verso, column a, line 12.)

(ix) On the elements' control of medicines. Beginning 'Nod leat dor[eir] Roigriani(?) co fuil[id] gneiti dona l[eige]saib'. (Folio 4 verso, column a, line 19.)

(x) On veins and arteries. Beginning 'Tractadh (ann) so arna tarring a le(a)bruib Laidian'. Ends 'a timceall bona na cluasi'. (Folio 4 verso, column a, line 44.)

(xi) Quiz on physical topics. Beginning '(Ca) dath ata ar in teinidh? Ni [ansa]. Ni fuil dath uirri'. Ends illegible. (Folio 4 verso, column b, line 47.)