Kitāb Jālinus ’ilā Ghlūqun (Therapeutics to Glaucon) by celebrated translator and scholar Hunayn ibn Ishaq al-ʻIbadi (circa 809–73) consists of two treatises by the Greek physician Galen (Jalinus in Arabic, circa 131–201). Husayn explains that the Greek physicians of the great medical school at Alexandria classified works by Galen into various categories for students. The first category included four books as introductory works to medicine: 1, a treatise on medical sects; 2, a small work on the art of medicine; 3, a book on the pulse, and 4, the work presented here, Kitāb Jālinus ’ilā Ghlūqun. The first treatise opens with a classification of diseases according to their cause and proceeds to a discussion of the causes of fevers and of their treatment. This section is followed by a section on headaches, including hemicrania. The second treatise, which is shorter, deals with swellings and their underlying cause, which is presented as the overabundance of one of the four humors of the body: black bile, yellow bile, phlegm, and blood. The treatise also presents various treatments and medications for restoring balance to the humors. Galen was one of the greatest and most prolific medical writers in classical times. He was born in Pergamon, in present-day Turkey, and spent much of his life in Rome, where he promoted the ideas of Hippocrates. He emphasized dissection (of apes and pigs), clinical observation, and thorough examination of patient and symptoms. Galen addressed the work on which this manuscript draws to Glaucon, who was also a physician and was his pupil. The manuscript is written in naskh script and black and red ink.