Historical reference: Do not rely on this information. It is very old. About this collection
Castanets, from the Spanish word for chestnut, are two hollowed pieces of wood or ivory, shaped like the halves of a chestnut, and joined by a band or cord which passes over the thumb, the two halves falling into the hollow of the hand. They are used to make a rattling accompaniment to music or dancing, and serve to mark the rhythm. The Moors are said to have introduced them into Spain; and the krotalon of the Greeks served a similar purpose. Nature has provided the rattlesnake with castanets, which however differ in shape from those used in Spain.