The Treatise of Sage Uromarishi.

Stir it repeatedly with a small stick, and when you place it in the
heat of the sun original: "ravi", referring to the sun; this process is known as 'surya-putam' or solar digestion day after day, all the powders you have
added will show their quality by forming a film like the cream on milk.
When you first pour in the thickened fruit juice likely lime or citrus juice used as a solvent,
the essence will settle properly; you must strike while the timing is right.

If the strength of those who perform this is great, all the juices
will evaporate day by day—this is the path. When the surface
appears clear, boil it until the juice is fully dried, and see how it
turns a pure white. Look closely: take one Palam (a weight of approx. 35 grams)
each of Kantham (Magnetite/Magnetic iron ore) and Sikki (a specific mineral, likely a silicate or flint).
To protect the mixture, take one Kazhanju (a weight of approx. 5 grams)
each of Alum, Pooram (Calomel/Mercurous chloride), Saram (Sal ammoniac),
and Gevuri (Yellow Arsenic/Orpiment). Observe these four ingredients.

Grind these four ingredients together with the Sikki until they are like
fine soot. Take these five and powder them well. Into one part of
mature Savukkaram (a caustic alchemical salt or "soap-salt")—dissolved in
acid—add the white calcined powder of clam shells and conch shells.
Add a Viragan (a weight of approx. 3.5 grams) of this. Truly,
the water will boil and hiss "mullu-mullu." This water from the shells,
which has become a "Guru" a transformative catalyst and does not settle
even by a quarter-measure, should be poured in. Stir and grind it well.

Grind it so that all the combined substances are completely
incorporated—O Noble One! The acid Thiravagam (literally "liquid essence" or potent acid)
is very swift in its action. Kindle the heat and grind for two Samams (a period of 3 hours each, totaling 6 hours)
without becoming weary, until it reaches the consistency of a fine,
waxy paste. Listen further: take the powerful Chunnam (calcined lime/powder)
made from the shells of Andam (the "egg of the world," usually referring to hen’s eggs)
and join it with the acid.