What is "yachay"

Yachay is a special type of phlegm generated by shamans and sorcerers of the Peruvian Amazon Basin which is believed to contain the essence of their power in the form of virotes, tsentsak, darts, arrows, or splinters of bone that are believed to be contained in the phlegm. It is believed that these may be fired from the mouth, and that being pierced by virotes causes various conditions. These may be removed by a shaman, who sucks them out of the victim's body.