The reanimation device is a piece of technology originally built by the Ancients. Designed in the shape of a cube which emits rays of light when activated, its primary purpose was to heal.
Thousands of years ago, the Goa'uld Telchak found the device, which has also come to be known as "Telchak's device." He had hoped to benefit from its technology, but the device was so powerful that his attempts to use it on human hosts ultimately proved devastating. After much research and experimentation, Telchak was able to modify the technology to create the first sarcophagus, however he was unable to eliminate all the negative side effects to which the sarcophagus is still prone.
Anubis went to war with Telchak for possession of the reanimation device, and although Telchak was defeated, Anubis never did acquire the device, which was believed to be hidden in one of Telchak's many temples. The device was probably the basis of the Fountain of Youth mythology, linked to early Mayan tribes dating from 900 BC and attributed to Chac, the Mayan god of rain, who was most likely the Mayan incarnation of Telchak. Daniel's grandfather, Nicholas Ballard, had sought the Fountain of Youth and the alien technology he believed to be hidden near a waterfall in Central America, and his notes later led Daniel and Dr. Lee to discover the reanimation device buried in the jungles south of Tegucigalpa, Honduras.
Anubis's later access to Ancient technology had allowed him to use technology similar to the reanimation device to give life to the synthetically created hosts of his Kull Warrior army. SG-1 hoped that by retrieving the device they could analyze the technology in order to engineer a weapon that would counteract its life-giving energy and defeat the Kull Warriors, as well as to harness its power to heal when used at a safe distance with very limited exposure. Before Daniel could return from South America, however, he was kidnapped by Rafael and his guerillas, who activated the device. Exposure to its energy caused madness and a sense of invincibility, and when Chalo was shot and killed, the device's energy reanimated the dead tissue and repeatedly brought him back to life. Similar technology may have also been responsible for the repeated reanimation of Volnek, the Sodan warrior who was cursed by the Ori to kill his own people.
After Daniel's rescue, the reanimation device was returned to the SGC where Carter and Jacob studied its technology and were able to devise a prototype energy weapon that, with modifications, proved effective in neutralizing Anubis's Kull Warriors.
Cross Reference: Ancients, Nicholas Ballard, Burke, Chalo, Rogelio Duran, Energy Weapon, Fountain of Youth, Kull Warrior, Bill Lee, Rafael, Sarcophagus, Telchak, Volnek
Episode Reference: Evolution