thanks to prince charles.even then international people disbelive and donot approve siddha medicines.if archeologist r believing with the evidences why cant international medicals belive siddha medicine.preperation purification r done by siddha doctors as per classical text books.mercury is poisin in crude form but is a very good rejunivator when purified and prepared.in allopathy on the label of drugs v can see warnings that to keep away from children it is poison but not in siddha medicine.i hope better future for siddha medicine .thank u.