Eleven years after the above lines were written, there appeared in Madrid a study of Dante’s relations with Mohammedan Eschatology,[320] which may possibly prove to hold the key to some of the problems raised by the _Gospel of Barnabas._ The learned Spanish Professor of Arabic is by no means the first to explore the field of possible Oriental sources for the Divine Comedy. Since Ozanam wrote his _La Philosophie Chrétienne avant Dante_, a number of writers—D’Ancona, D’Ovidio and others in Italy, and Vossler in Germany—have busied themselves with this subject; and in 1901, M. Blochet[321] brought both the general idea of the Unearthly Pilgrimage and some of its details into what looks like a derivative relationship with the two great Oriental Ascension-myths: the very ancient Mazdean story of Arda-Viraf, of Persian origin, and the secondary legend of Mohammed’s one-night journey through the heavens, founded on a short and obscure passage in the _Koran_[322] and known as the _Miradj_. Together with other researchers in the same field, M. Blochet brings in also Sinbad the Sailor, the Voyage of St. Brendan, and all the family of the Quest of the Fortunate Isles; working up the pedigree right back to the Hesperides of the Hellenic myths—themselves descended from an ancestry more ancient still, and of origin further East. He suggests the many possible channels of transmission of oriental lore to Western Europe, and in particular to Ireland[323] by the more easterly “Amber Route” which archaeology shews to have passed from Mesopotamia over the Caucasus and through Russia to the Baltic. He points again to the openings made by the Crusades, and singles out the work of Dante’s Venetian contemporary, Marin Sanudo, _Liber secretorum fidelium crucis_,[324] as evincing such a mastery of the entire “Eastern Question” as would imply a very exact knowledge of the Moslem religion and its legends. He points also to Paget Toynbee’s demonstration of Dante’s indebtedness in no less than ten passages of the _Vita Nuova_ and _Convivio_, to the Moslem astronomer Djaafer-îbn-Mohammed-el-Balkhi, known to the mediaeval West by the less cumbrous name of Alfraganus.[325] New ground has, however, undoubtedly been opened up by Dr. Asín. In his Inaugural Lecture he makes claims which, no doubt, will be fiercely combated, and in the end largely discounted. Dr. Parodi in his important notice of this book[326] points out that Asín’s contention is two-fold, and one half of it, at least, unprovable. The Spanish Orientalist claims to have proved (1) that the Western legends of the World Beyond are derived from Arab (and ultimately from Persian) sources, (2) that Dante was acquainted with specific Moslem sources, and used them freely.