To those who believed that the earth was flat it was somewhat startling to be told that there were antipodes. This elementary truth of cosmology Bishop Virgil of Salzbourg was courageous enough to assert as early as A.D. 764. He wrote a book in which he stated that men of another race, not sprung from Adam, lived in the world beneath our feet. This work aroused the anger of Pope Zacharias II, who wrote to the King of Bavaria that Virgil should be expelled from the temple of God and the Church, and deprived of God and the Church, and deprived of his office, unless he confessed his perverse errors. In spite of the censure and sentence of excommunication pronounced upon him, Bishop Virgil was canonised by Pope Gregory XI.; thus, in spite of his misfortunes brought about by his book, his memory was revered and honoured by the Western Church. If the account of his imprisonment be true (of which there is no contemporary evidence) our own celebrated English philosopher, Roger Bacon, is one of the earliest scientific authors whose works proved fatal to them. In 1267 he sent his book, _Opus Majus_, together with his _Opus Minus_, an abridgement of his former work, to Pope Clement IV. After the death of that Pope Bacon was cited by the General of the Franciscan order, to which he belonged, to appear before his judges at Paris, where he was condemned to imprisonment. He is said to have languished in the dungeon fourteen years, and, worn out by his sufferings, to have died in his beloved Oxford during the year of his release, 1292. The charge of magic was freely brought against him. His great work, which has been termed "the _Encyclopaedia_ and the _Novum Organum_ of the thirteenth century," discloses an unfettered mind and judgment far in advance of the spirit of the age in which he lived. In addition to this he wrote _Compendium Philosophiae_, _De mirabili Potestate artis et naturae, Specula mathematica, Speculum alchemicum_, and other works.