As a matter of fact it is no such thing. This title, together with an extra title-page and colophon in the same hand, is a much later addition to the MS., which also has a fragment of some other medical work--at present unidentified--bound up with it. The folios of the MS. which deal with the _Tractatus_ have been bound together in extreme disorder, but examination of them has shown that they really form a fragment of the second book of ‫المختار قي الطبّ‬, the _Delectus de Medicina_, by ‫مهذب الدين ابو الحسن على بن احهد البغدادي‬, Muhaḏḏib ed Din Abu’l Hasan Ali Ibn Aḥmad of Bagdad.[360] Ibn Abi ‛Uṣaibia (1203-1269)[361] gives a life of this writer and a list of his works, which includes the _Delectus de Medicina_. According to him, Muhaḏḏib ed Din was born at Bagdad in A.H. 515 (= A.D. 1121), and after studying medicine and philosophy settled at Mosul. Later he became the physician of the Shah Arman, chieftain of Khalāt on Lake Van in Armenia, in whose service he amassed great wealth. He completed the _Delectus_ at Mosul in the year A.H. 560 (= A.D. 1164), and died there in A.H. 610 (= A.D. 1213), with the reputation of being first physician of his time. Another fragment of the same work of Muhaḏḏib ed Din, which includes most of the contents of the Bodleian MS., besides a good deal of material which has been lost from the latter, exists in the British Museum.[362] The Leyden Library contains a unique copy of the work in three books. This is claimed to be complete by the Catalogue of the library,[363] although Bar Hebraeus [1226-1286]--Catholicus of the Jacobite (Monophysite) Church[364]--says that the work ran into four parts.[365] The three books of the Leyden MS. treat (i) of generalities (i.e. Anatomy, Physiology, and the general causes of disease), (ii) of medicaments, and (iii) of particular diseases and their treatment. The Bodleian and British Museum MSS. contain part of the third book, which was probably in general use by itself as a dictionary of medicine. The British Museum copy has only lost the earlier chapters of this third part, but the Bodleian MS., although possessing a few more chapters at the beginning, is far less complete in the other portions.[366]