Ernst work on narcotics is his most famous and was recently translated into English and publish under the title "Plant Intoxicants". (). This was one of the first books to examine the cultivation, preparation, and consumption of the world’s major stimulants and inebriants. The book includes seventeen chapters : 1) coffee, 2) coffee leaves as a beverage 3) tea, 4) Paraguayan Tea (yerba maté), 5) Guarana, 6) chocolate, 7) Fahan Tea (the orchid Angraecum fragrans Thouars as a source of coumarin), 8) Khat, 9) Fly Agaric (Amanita muscaria) opiate derived from the "poison lettuce,"10) thorn apple, 11) coca, 12) opium, 13) Lactucarium 14) hashish, 15) tobacco 16) Betel and Related Substances (Areca catechu, areca nut; Piper siriboa, the betel leaf) and 17) arsenous acid or arsenic trioxide (As2O3). Because of Ernst's early investigation and writing on coffee, he is occasionally referenced in modern coffee literature.