Anandakanda 1.10.17

1.10.17

tamādāya baliṃ kṣiptvā siddhacūrṇena pārvati /
tatastaṃ bhūdhare yantre pacellaghupuṭena ca //

Taking it out and throwing sulphur [over it], O Pārvatī, along with the perfected powder,
one should then cook it in a subterranean apparatus with a light incinerating pit.