Rasendracudamani 14.118

14.118

{iron:: mṛta:: medic. use}
tadaṣṭapalikaṃ bhasma mūtrair aṣṭaguṇair gavām /
pacellohamaye pātre lohadarvyā vighaṭṭayet //

[Medicinal use of dead iron:]
That ash, in the amount of eight palas, one should cook with eight times as much cow's urine
in an iron vessel, stirring it with an iron ladle.