can only mean Bagdad, the seat of the
caliphs and the relation of his embassy might have been
curious and instructive. But how did he procure his books?
A library so numerous could neither be found at Bagdad, nor
transported with his baggage, nor preserved in his memory.
Yet the last, however incredible, seems to be affirmed by
Photius himself, 
Camusat (Hist. Critique des Journaux, p.
87 - 94) gives a good account of the Myriobiblon.