Kautilya's Arthashastra 2.14.20

2.14.20

rūpyasya dvau bhāgāv ekaḥ śulbasya tripuṭakam //

When, by what is called Triputaka which consists of two parts of silver and one part of copper, an equal portion of pure alluvial gold is replaced, that deceitful act is termed copper-removal (triputaká- vasáritam); when, by copper, an equal portion of gold is replaced, that act is termed copper-removal (sulbávasáritam); when by vellakaan equal portion of gold is replaced, it is termed vellaka-removal; and when pure alluvial gold is replaced by that gold half of which is mixed with copper, it is termed gold removal (hemávasáritam).