The Essence of Mercury

...should then be placed in an underground pit for twenty-one days. (55)
This is called the regulator niyamaka, and it acts as a friend to fire.

Having coated a glass flask kaca-kupi with mud, place the mercury inside. (56)
Add one sixteenth part of borax tankana and provide a little alcohol. One should seal the opening firmly with a stopper of diamond-like clay. (57)
Having placed the flask in an underground pit, fill the pit according to the aforementioned method. A fire of cow-dung cakes should be performed for twenty-one days. (58)
This is called the fixer nirodhaka, which is supreme and brings great ease. The fixing of the King of Mercury sutaraja is the preventer of indigestion i.e., it ensures the mercury is safely assimilated by the body. (59)
The sweating of the King of Mercury with alkaline acids, poisons, and alcohols: having taken a citron bijapura, make a hole in its stem. (60)
Place the mercury inside it, combined with one sixteenth part of alkali. Having blocked the opening, bind it with a cloth with effort. (61)
The "swinging sweat" dola-sveda should be performed for twenty-one days. Every day, one should use a new citron. (62)
Licking up the metals and being urged by hunger, it should be purified as the King of Mercury. (63)
Three days, or seven days, or fourteen, or twenty: the process for the King of Mercury is better in successive stages. (64)
A little gold should be given for the sake of happiness.
"Om salutations to the immortal metal, born from the supreme nectar, svaha." (65)
This is the mantra for charging and eating charana-jarana.