"Siddhargal" or Siddhars were the premier scientists of ancient days. Siddhars, mainly from Southern India, in the state of Tamil Nadu laid the foundation for Siddha system of medicine. Siddhars were spiritual adepts who possessed the ashta siddhis. Agastyar or Agasthya, is believed to be the founding father of Siddha Medicine. Eighteen Siddhars are considered to be important in the Siddha Medicine. Siddha medicine is claimed to revitalize and rejuvenate dysfunctional organs that cause the disease and to maintain the ratio of Dosha. Kayakarpam (special combination of medicine and life style) and Muppu (the universal Salt) are speciality of Siddha system of medicine.