This entry in the Encyclopedia of Taoism (Routledge 2008) is quite a big, has two parts, and the first part titled Waidan (by Kim Daeyeol) I am going to skip totally and my reason is that waidan (external alchemy) teachings were never important to me: I have enough gold in my pockets to switch myself to neidan (internal alchemy) schools forever :))
A couple of quotes from the entry can help us to understand some ideas and details (Monica Esposito):
“In neidan, fire phasing constitutes the rhythm of the inner alchemical work: the Art of Measure. Through it, the alchemist knows how to measure the ingredients (yàowù 藥物), when to increase or decrease the Fire, and so on. The term huŏ 火(fire) refers to the circulation of vital breath (qi), or simply the power of the effort in practice, while hòu 候 (phase) denotes the sequence in which the practice is performed. Fire phasing therefor represents the most secret part of neidan, the inner rhythm that one must find and experience for oneself”.
I like it, ‘simply the power of the effort in practice’; ‘sequence’ for me almost always means ‘algorithm’, and ‘inner rhythm’ sounds like no one is fooling around.
Seriously, (M.E.): “Fire phasing in neidan means that in every instant the practitioner should find the balance between Martial Fire (action, movement, temporal expansion) and Civil Fire (inactivity, immobility, temporal reduction). Alchemical texts repeatedly state that this is the innermost secret of the alchemical work, which cannot be transmitted in words”. Yes, secret, but if we open some medical tractates, famous, classical, and widely spread, and stick to ‘balance’, guess what? No secrets anymore, just a highway smart people can go everywhere.
So, we have been told (twice) that alchemical texts and ‘alchemical people’ will keep the algorithms of their works in secret and what kind of ideas can be helpful for us now? I guess, only one. Considering the fact that philosophy inside waidan/ neidan teachings is almost the same (ba gua, seasonal changes, Yijing hexagrams, lunar month, days, and hours, wuxing theory, and our favorite yin-yang compounds) we can rely on themselves and just figure out how it can be applied to our everyday life.
By the way, if all this work will be done by you, the all results will be only yours, innermost and undeniably straight and strong, right? And this is my story. And this is the story I am keeping to tell people around me. Just 100% unsuccessfully :))