Tableaux de la nature, ou Considérations sur les déserts, sur la physionomie des végétaux, et sur les cataractes de l’Orénoque; Q Science
Letters of Alexander von Humboldt to Varnhagen von Ense. From 1827 to 1858. With extracts from Varnhagen’s diaries, and letters of Varnhagen and others to Humboldt Q Science
Physiology: a manual of 1000 questions and answers systematically arranged, containing a full treatment of the physiological effects of alcohol and narcotics Q Science
