[The duration and amount of fire (huo hou) in drug processing].

The unique connotations for the special terms such as slow fire (wen huo), strong fire (wu huo), moderate fire (wen wu huo), ma tong fire, husk fire (kang huo), reed fire (lu di huo), mulberry fire (sang cai huo) and charcoal fire (tan huo) are investigated. There are many practical examples of these terms in related literature. The drug process is related to the alchemy in Taoism. The methods of fire control in drug processing are mostly from the literature on Alchemy (dan jing). The expression of these special terms and their connotations are different in various literature, because of their different traditions.