Mercury is first combined with sulphur to form a black sulphide and used as base material in these preparations. Mercury is processed with a variety of drugs and heated to form sulphides. These are very potent medicines in the Indian system of medicine. They are prepared by the process of sublimation. They are similar to Ghrta, but here the base is oil, not ghee.
Most preparations use sesame oil.
Coconut, Castor or Neem oils are also used. Rare cases include Mustard or Chaul Moogra oil. Taila are used mostly for external application. Medicated oils are powerful stimulants and counter irritants. They can also be cooling and sedative in nature.