Anandakanda 1.23.53

1.23.53

<caturthaḥ prakāraḥ>
niyāmakauṣadhairmardyaṃ caturyāmaṃ rasaṃ dṛḍham /
dviguṇe gandhataile ca śanairmandāgninā pacet //

<Fourth method> / One should grind mercury firmly for four yāmas with regulatory herbs, / and cook it slowly over a gentle fire in double its amount of sulphur oil,