The Divine Comedy by Dante, Illustrated, Purgatory, Volume 5 It is is biographical book. While singly thus along the rim we walked, Oft the good master warned me: 'Look thou well. Avail it that I caution thee. ' The sun Now all the western clime irradiate changed From azure tinct to white; and, as I passed, My passing shadow made the numbered flame Burn ruddier. At so strange a sight I marked That many a spirit marveled on his way. This bred occasion first to speak of me, 'He seems, ' said they, 'no insubstantial frame:' Then to obtain what certainty they might, Stretched towards me, careful not to over pass The burning pale.