SENIOR. Muhammad ibn-Umail al-Tamimi, fl. A.D. 900-960, was called al-Sadik. In English al-Sadik becomes "Zadith" and ibn-Umail is translated as "son of Hamuel." He wrote three treatises on alchemy, the most famous of which is Kitab al-ma' al-waraqi wal-ard an-najmiyah, or The Book of the Silvery Water and the Starry Earth. Ibn-Umail wrote it as a commentary on an alchemical poem, Risalah ash-Shams ila 'l-hilal, translated in Latin as Epistola solis ad lunam crescentem (The Letter of the Sun to the Waxing Moon, no date given) and attributed to "Senior Calid filius Hahmil" in medieval manuscripts. This attribution indicates some confusion between ibn-Umail and Khalid ibn-Yazid, referred to in the Latin text of "the Book Senior" as "Calid filius Seid," or, more correctly, "Calid filius Isid." The Latin work was published in volume V of Zetner's Theatrum chemicum in 1622.

The Canon's Yeoman tells the story of one of Plato's disciples as found in Senior's book, CYT 1448-1471. J. Ruska points out that the Arabic text mentions neither Solomon nor Plato, but Qalimus, who discourses on chalk and lime (Greek titanos). In Tabula chemica, chapter Tincture operatio, the story is told about Solomon, not Plato. E.H. Duncan shows that Chaucer uses an edition of Epistola solis in which Dixit Senior, i.e., Plato ("Senior, that is Plato, says"), is written in the margin of one fourteenth-century manuscript.

Senior, the Latin translation of the Arabic title, Sheik, appears medially, CYT 1450.