Anandakanda 1.4.261

1.4.261

puṭet ṣoḍaśabhistacca śatadhā hemni vāhayet /
<caturthaṃ tāmrabhasmasiddhaṃ hemabījam>
athavā mārayecchulbamūrdhvādho gandhakaṃ samam //

One should calcine it with sixteen puṭas, and project that a hundred times into gold.
<The fourth gold seed, prepared with copper ash>
Or one should kill copper: placing equal parts of sulfur above and below,