This rare wig powdering carrot dates from the late 1700s. The top unscrews to allow powder to be placed inside, by sliding the cover to one side.  The powder was typically made of starch, sometimes scented, for the wigs. The small turned horn mouth piece at the other end would have been blown and the powder dispersed over the wig, and everywhere else!
These were used when fitted wigs were the height of fashion amongst gentleman, judges and military officers.
Interestingly in 1795 Britain introduced a tax on hair powder, which led to the sharp decline of powdered wig use — this helps date many powderers to pre-1800.