Though the Siddhas and Siddha medical system have been conceived and considered as one, their exact relation is doubted by some scholars 10 . Some scholars accuse Aryans for meddling with Siddha medicine and circulating it as Ayurvedic system 11 . The confusion has been evidently due to the fact that there has been deviation in the methodology of Siddha medical system from Tirumular to latter-day Siddhar of 17th to 20th century period after the pursuit of alchemy. The traditional Siddhas only advocated the longevity of life through breadth control and yoga, but, the Siddhas of latter period, evidently from 17th century started attempting with kaya kalpam / elixir, and so on. The transition from the usage of herbs to different minerals / Chemicals can also be noted in their medicinal preparations. Thus, the Siddha medicinal system can be distinctly grouped / differentiated as follows:
“…To sum up, in short, the Tirumandiram is a work, whch deals with how one may live a divine life in the midst of the worldly one. It fulfills the meaning of the word “Tantra” a “web” which joins the spiritual and the material dimensions of life. It expresses the thread of unity, which exists behind the many differences of time, country, language, caste, religion, higher and lower, happiness and misery, wealth and poverty. It deals with all the aspects of life, which makes life worth-living by dealing with dharma, artha, kama, moksa, tapas, Yoga, jnana, siddhi, buddhi, mukti, planets, days, the art of breathing, mantra, tantra, yantra, cakras, meditation, medicine, et. In short, it is a Tamil encyclopedia of philosophical and spiritual wisdom rendered in verse form.”
Tamil Nadu has the country's third longest coastline at about km ( mi).  Tamil Nadu's coastline bore the brunt of the 2004 Indian Ocean tsunami when it hit India, which caused 7,793 direct deaths in the state. Tamil Nadu falls mostly in a region of low seismic hazard with the exception of the western border areas that lie in a low to moderate hazard zone; as per the 2002 Bureau of Indian Standards (BIS) map, Tamil Nadu falls in Zones II & III. Historically, parts of this region have experienced seismic activity in the range.