Opium, how obtained, properties and uses of, [154], [155]
——, how cultivated in England, [155]
——, how adulterated, [154]
Orange, flowers, juice and peel, uses of, [194], [195]
——, Seville or bitter, [195]
Orchall, description, preparation, and use of, [270]
Orders of plants, [4]
Orenberg gum, of what made, [237]
Orris root, description and uses of, [17]
Osier, wood and bark, uses of, [243]