[18]. ‘Die Höhlenkunde des Karstes.’ Wien, 1854.
[19]. ‘Flora Fribergensis Plantas Cryptogamicas præsertim subterraneas exhibens.’[exhibens.’]
[20]. ‘Vegetabilia in Hercyniæ Subterraneis collecta Norinbergæ.’ 1811.
[21]. Torches are not allowed to be carried in the Grotto of Adelsberg, that the whiteness of the stalactites may not be tarnished by the smoke.
[22]. Voyages in the Lighthouse Yacht, published in Lockhart’s ‘Life of Sir Walter Scott.’
[23]. Kinglake.
[24]. Shakespeare, ‘Tempest,’ iv. 1.
[25]. ‘The Crescent and the Cross.’
[26]. ‘Ice Caves of France and Switzerland: a Narrative of Subterranean Exploration.’ By the Rev. G. F. Browne. Longmans, 1865.
[27]. Burslem, ‘A Peep into Toorkistan.’