Anandakanda 1.5.65

1.5.65

kuṭilaṃ pannagaṃ jāryaṃ navasaṃkhyākrameṇa tu /
dattvā krameṇa deveśi koṭivedhī bhavedrasaḥ //

Crooked lead should be digested in increments of the number nine; / administering it in sequence, O mistress of gods, mercury becomes a ten-millionfold transmuter.