Anandakanda 1.25.107

1.25.107

<lepavedhaḥ>
lepena kurute lohaṃ svarṇaṃ vā rajataṃ tathā /
lepavedhaḥ sa vijñeyaḥ puṭamatra ca saukaram //

[Lepavedha:]
When one transforms base metal into gold or silver by anointing,
that is to be known as lepavedha, and the heating here is done in a saukara furnace.