Anandakanda 1.23.148

1.23.148

<ṣaṣṭhaḥ prakāraḥ>
tāmrakhalve palaṃ sūtaṃ karṣārdhaṃ gandhakaṃ kṣipet /
mṛdvagninā pacedyāmaṃ karāṅguṣṭhena cālayet //

<Sixth method>
One should place one pala of quicksilver and half a karṣa of sulphur in a copper mortar;
one should cook with gentle fire for one watch, stirring it with the thumb.