Copper in Ancient India c11.s2.7

c11.s2.7

"Each charge of shale is exposed to three changes of water and itself is changed from one gharā to another till it has taken up the sulphates from seven different steepings. It is then of a thick dirty-bluish colour and is taken to the boiling house where it is boiled in earthen gharās; when sufficiently concentrated it is left to cool and then sticks being introduced the