In his notice of the philosopher Abū Bishr, of Dair Ḳunnā, Ibn al-Ḳiftī mentions that he had a public discussion with the grammarian Abū Sa‘īd al-Ḥasan al-Sīrāfī, famous for his commentaries on Sībawaihi's grammar. This discussion is reported at length by Yāḳūt in his invaluable Mu‘jam al-udabā, on the authority of Abū Ḥayyān, from whose works Yāḳūt derives much that is interesting, though he accuses Abū Ḥayyān of habitually romancing. Abū Ḥayyān, whose full name was ‘Alī Ibn Muḥammad al-Tauḥīdī, was an eminent writer of the fourth century of Islam, of whose works only three (to the best of my knowledge) have as yet been published: his treatises on Friendship and the Sciences, printed at the Jawā‘ib press in 1301 a.h.—without the very important treatise on the lives of the two viziers Ibn al-‘Amīd and Ibn ‘Abbād, which had been promised in advertisements, but which is said to be a book that brings ill-luck; and a work lithographed in India called Muḳābasāt. A brief account of him is given by Ibn Khillikān in his life of Ibn al-‘Amīd (translated by De Slane, iii, 264) ; a lengthier one by Ṣafadī, which Mr. Amedroz has kindly copied for me, and which is given in a note; and a very lengthy one by Yāḳūt, in the fifth volume of his dictionary. An extract from one of his works, which occurs in al-Ḳiftī's dictionary, is translated into German by Dieterici (“ Philosophie der Araber,” i, 144).