Rasarnava 11.122

11.122

aṣṭāṃśena tato grāsaṃ garbhadrāvaṃ ca pūrvavat
kandodare sūraṇasya taṃ vinikṣipya sūtakam
puṭettu jāritastāvat yāvat kando na dahyate //

Then [give] a morsel of an eighth part, and the liquefier of the interior as before. / Having placed that mercury inside an elephant-foot yam tuber, / he should calcine it until it is digested, so long as the tuber is not burned.