ff. 1r-20v of MS 163 contain the text on medicine, known as Isagoge Ioannitii ad Tegni Galieni ('Hunayn's Introduction to the Art of Galen'). This text was composed in Baghdad in the 9th century by physician and scholar, Hunayn bin Ishaq (known in the West as Ioannitius). Hunayn bin Ishaq's work was based on Galen, and it came to form the central text of a collection of bound medical treatises used to teach medicine in the Middle Ages, the 'Articella'.

This text by Hunayn bin Ishaq was incredibly influencial on Western Europe, when it was transmitted there in the 12th and 13th centuries. It introduced the Galenic theory of naturals (elements, humours, and the qualities contained in and part of living beings), nonnaturals (the things needed to sustain life, such as food, air, sleep, motion) and contranaturals (things that worked against life, such as disease, and also causes and symptoms of illness) in medical thought.

The text begins on f. 1r with the words Incipiunt Ysagoge Johannicii in microtegni Galieni. Medicina dividitur in duas partes idest theoricam et practicam. Quarum una theorica in tria...

The text ends on f. 20v with the words Qualitatis. Quantitatis. Temporis. Ordinis. Boni mali ve discretio. Explicit Ysag in tegni.