Native to the Spice Islands, this seed from the nutmeg tree (a tropical evergreen) was extremely popular throughout much of the world from the 15th to the 19th century. When the fruit of the tree is picked, it is split to reveal the nutmeg seed surrounded by a lacy membrane that, when dried and ground, becomes the spice MACE. The hard, egg-shaped nutmeg seed is grayish-brown and about 1 inch long. The flavor and aroma are delicately warm, spicy and sweet. Nutmeg is sold ground or whole. An oil is a substance that is in a viscous liquid state ("oily") at ambient temperatures or slightly warmer, and is both hydrophobic (immiscible with water) and lipophilic (miscible with other oils, literally). This general definition includes compound classes with otherwise unrelated chemical structures, properties, and uses, including vegetable oils, petrochemical oils, and volatile essential oils. Oil is a nonpolar substance.