and energy." Cinnabar could also be roasted, which produced a liquid form of silver known as quicksilver, now known as mercury. This substance was ingested but it could also be combined with sulphur and burned again to return to its natural form of cinnabar, the solid seen as the yang to quicksilver's yin. In China, gold was quite rare, so it was usually imported from other surrounding countries. However, cinnabar could be refined in the mountains of Sichuan and Hunan provinces in central China. Although the majority of xian (immortality) elixirs were combinations of jindan, many other elixirs were formed by combining metallic bases with natural herbs or animals bi-products. The rhinoceros' horn was commonly used in medicines and elixirs and was held to have fertility-increasing abilities. Elixirs were composed of metallic compounds such as gold and silver, but could also be made of more lethal components like arsenic, and sulphur. East Asian vs Eastern Mediterranean views Both the Eastern practice and the later Western practice of alchemy are remarkably similar in their methods and ultimate purpose. To be sure, the desire to create an elixir of immortality was more appealing to the Taoists, but European alchemists were not averse to seeking out formulas for various longevity-boosting substances. The secret of transmuting one element into another, specifically base metals into gold or silver, was equally explored by both schools for obvious reasons. In the European outlook, the ability to turn relatively worthless materials into gold was attractive enough to allow medieval alchemy to enjoy extensive practice long after the Chinese form had been forgotten. Alternatively, transmutation was also a means of accruing the precious metals that were key in making life-extending elixirs, and were otherwise expensive and difficult to obtain. Alchemical knowledge in the East and West favored different opinions of the true form of alchemy due to different theological views and cultural biases, however these disputes do not lessen the integrity of alchemy's canonical nature. Chinese alchemy specifically was consistent in its practice from the beginning, and there was relatively little controversy among its practitioners. Definition amongst alchemists varied only in their medical prescription for the elixir of immortality, or perhaps only over their names for it, of which sinology has counted about 1000. Because the Chinese approach was through the fundamental doctrine of Yin and Yang, the influence of the I Ching, and the teachings of the Five