An early to mid 19th century pocket treen nutmeg grater in the shape of the wine bottle of the period. This one unscrews in the middle to reveal the grater and storage space for the nutmeg.
The cork turned in wood, at the top of the wine bottom lifts off.
These small antique nutmeg graters were carried around in pockets and used for grating nutmeg into mulled wine or punch. Nutmeg graters were a real status symbol. Around the middle of the 19th century the price of nutmeg began to drop and became more affordable.