Anandakanda 2.1.250

2.1.250

daśāṃśaṃ ṭaṅkaṇaṃ dattvā pācyaṃ mṛdupuṭe tataḥ /
puṭaṃ dadhnā puṭaṃ kṣaudrairdeyaṃ tutthaviśuddhaye //

Adding a tenth part of borax, it is then to be roasted in a gentle puṭa;
a puṭa with curds and a puṭa with honey should be given for the purification of vitriol.