In ancient times, the chewing of coca leaves was part of certain religious ceremonies in different cultures in the Andes of South America. The stimulant properties of the leaves are enhanced by adding a little bit of quicklime, as this helps neutralize stomach acid and increase the absorption of the alkaloids into the bloodstream. This lime was kept in ceremonial vessels known as poporos. Pablo Ramirez built this rendition of the Poporo Quimbaya, a gold artifact of the Quimbaya civilization dated to about 1700 years ago. This container has become somewhat of a symbol of pre-Columbian culture in Columbia, and appears on some of their currency.
*While the practice of chewing coca leaves was restricted to upper classes in certain ceremonial uses in earlier times, in recent centuries it has become very common in some Andean regions. This has become a source of contention, as the US and international organizations wanting to stop the production of cocaine have come up against poor farmers who defend the production and chewing of the leaves (with a small amount of lime) as an indigenous practice. I've read conflicting reports from people on both sides of this, with some referring to the practice as essentially a low grade cocaine addiction, and others saying it is a folk remedy for altitude sickness and less of a kick than a cup of coffee.
**BTW, despite my title, the mineral lime used in the chewing of coca leaves has no relation to the citrus fruit lime. The word for the mineral comes from the Old English lim, which refers to a sticky substance, as lime was used in making mortar. The word for the fruit comes from the Arabic limah, referring to a citrus fruit. It's ironic that these two different meanings ended up with the same word in modern English, since the mineral is basic and the fruit is acidic. On the other hand, coca leaves are used in the production of Coca Cola, though ever since 1904 the leaves have first been processed to remove any cocaine.