Ogier Ghislain de Busbecq,
The Life and Letters of Ogier Ghiselin de Busbecq…
“ They do not mention the geographical position of this river (methinks it ought to be marked down in Dreamland) ; all they tell me is that it is concealed beneath a covering of deep darkness and thick night, and that no mortal since Chederle has had the luck to see it; but that Chederle himself, being released from the laws of death, rides to and fro on a gallant steed, which, like its master, has, by a draught of this same water, purged itself of mortal dross. ”
