Ancient Siddhars are known for their superior longevity, their mystical powers and the unique system of medicine which continues to be popular in South India. Siddhars were voracious writers. They documented their own experiences with Yogic powers, minerals and herbs in a scientific manner. They refined their learnings through discussions among themselves and periodically convened assembly of experts to approve literary works for publication. Some Siddhar masters taught thousands of students. A few traveled as far as China, Cambodia, Mongolia and Malasia. Books of Siddhars cross reference the works of contemporaries and predecessors. Some books are compilations of important information from an earlier era. Eighteen Siddhars are prominent among the list of Siddhars whose names find a mention in Siddhar texts. Agasthiyar and Bhogar were the most prolific authors among the Eighteen. They, like the others, wrote in a much older dialect of the Tamil language. Siddhar texts form a unique category of literature because of the writing style and the richness of technical terms within them. Siddhar masters either withheld or deliberately encrypted references to crucial techniques to encourage learning under the guidance of an expert. The followers of ancient Siddhars have preserved thousands of works from a distant past. Agasthiyar and Bhogar have written on a range of topics from pharmacology to self realization. Siddhars did not see a clear boundary among the varied topics which they studied. For example. they attribute the efficacy of their mineral preparations to the infusion of the Yogic power of the pharmacist. Agasthiyar has summarized the essential tenets of SIddhars in Tattuvam-300. This translation covers the second volume containing 100 verses from the Tattuvam-300 book. Agasthiyar has presented key ideas of Siddhars in terms of principles or tattvas in this second volume. The translation continues into the first half of the third volume which Agasthiyar calls the Gyana Kaandam or the volume of self knowledge. In it, Agasthiyar explains the schematic division of cosmic energies and their connection to sound energies. He then introduces the impact of sound energies on different chakras in the human body. Kaya Siddhi arises by channeling the subtle energy within the body through different chakras or energy centers in a specific manner. Longevity and other powers are a part of Kaya Siddhi. Siddhars believed in the importance of Vatha Siddhi or perfecting the body's energy system before attempting Kaya Siddhi. Agasthiyar introduces the topic of Vatha Siddhi in the first volume and concludes it in the third volume. He lists important pharmacological preparations of other Siddhars which are useful in perfecting the body's energy system. The primary goal of the Tattuvam-300 book is to establish the importance of knowledge about key principles before attempting to channel the body's energies. Special medicinal perparations come next. A stable intellect which is devoid of false concepts is the primary qualification for a student on the path of Siddhars. Principles or Tattvas are common to all Siddhars. However, Siddhars perfected different medicinal preparations at different time periods as aids to progress faster on the path.