Ancient Indian Chemistry
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Chemistry in ancient India wasn’t at all what it is today.
In ancient India, chemistry was called “Rasayana” in Sanskrit, the language in vogue. Rasayana derived its name from “Rasa,” which means “extract,” maybe from roots, leaves, and stems of plants.
Sages in ancient India used to extract juices from various plants and trees for their medicinal properties and, thus, in those forgotten ages, chemistry was essentially confined to being a branch of “Ayurveda,” the ancient Indian curative. In plants, the surplus nutrients are stored in the different parts as alkaloids, and these chemical compounds were used in the treatment of ailments in Ayurveda.
Initially, these alkaloids were extracted by simply grinding specific parts of plants into a slurry, but eventually, the ancient sage doctors designed sophisticated apparatus for distillation. “Damaru Yantra” was an apparatus mentioned in Ayurveda comprising of two equal earthen vessels placed in such a way that the rims of both met each other and were sealed with a mud-smeared cloth. The apparatus was then heated from the bottom while a cool cloth was applied to the top, which allowed the medicine vapor to condense and stick to the inside bottom surface of the top vessel.
They could prepare many oils, paints, and varnishes, and there was a great demand for these products all over the world. With the escalating need for newer products, the domain of ancient Indian chemistry broadened and many new metals were discovered; although non-metal chemistry wasn’t that developed in those days. The aboriginal Dravidians, who were ultimately forced to settle in southern India due to the Aryan migration to India and the subsequent tussle for land in Northern India, knew how to extract and utilize coinage metals and how to prepare bronze. But with the advent of Aryans, iron began to be used extensively. In ancient India, metals were discovered for four basic purposes. Jewelry was made by Dravidians with gold and silver; utensils and objects were made from gold, silver, copper, and bronze. Aryans came and made weapons with iron. Another important use of metals and alloys was in medicines for their therapeutic properties.
Pliny the Elder, a Roman author and philosopher from the 1st century AD, stated in his writings that gold coins were draining out of Roman Empire into India for their addiction to these Indian luxury products. In his own words, India, China, and the Arabian Peninsula took one hundred million sesterces from Roman Empire per annum on a rough estimate.
Indian alchemists tried to produce gold out of mercury by treating many plants and mineral products. But the million-dollar question is, “Why did those alchemists choose mercury out of the whole range of elements?”
Actually, the atomic number of mercury is 80, and that of gold is 79; thus, there is only one proton less in the nucleus of gold than that of mercury. So, if one proton can be driven out of the nucleus of mercury, then the mercury will no longer exist as mercury, but turn into gold. But how did this idea strike the minds of the ancient alchemists? Did they know the periodic properties of elements?
In modern times, mercury isotope 196Hg can be converted to stable gold isotope 197Au by slow neutron capture followed by electron capture. Thus, this is a proof of the high degree of understanding of chemistry as a whole in ancient India.
Nagarjuna, a great ancient Indian physician of the 8th century AD, could extract mercury (“Parad” in Sanskrit) by roasting Cinnabar ore, extensively found in the hills of “Gandhara” (now called Afghanistan), in the air and condensing the vapor. Initially, Mercury was used as a color, but subsequently, “Parad bhasma,” “Makardhwaj,” “Rasakapur,” “Parad gandhak,” “Kajjali,” “Rasaparpati,” etc., were prepared from mercury and used as medicines.
Acharya Prafulla Chandra Roy had mentioned in his work, “A history of Hindu chemistry from the earliest times to the middle of the 16th century, A.D,” that mercury compounds were used in ancient India. The sage physicians probably knew the importance of iron and, hence, used iron as a food supplement, like Loha Bhasma, to treat anemia and weakness. This implies that the sage physicians knew that iron forms an integral part of hemoglobin molecules responsible for carrying oxygen through the blood.
Patanjali was another scientist during the birth of the Christ stated in his book, “Lohashastra,” that rust-free steel was produced by melting iron stones (ores) in small ovens of charcoal. The Ashoka Pillars erected by emperor Ashoka the Great are living examples of the developed iron technology of ancient India. The pillars were manufactured from wrought iron by forge welding. The pillar’s resistance to corrosion is due to a passive protective film at the iron-rust interface. The presence of high amounts of phosphorus and slag and unreduced iron oxides in the microstructure of the iron, and the alternate wetting-drying in atmospheric conditions are the main factors in the formation of that protective passive film. Another important metal, arsenic, was discovered to treat many ailments.
Sulphur, charcoal, Hirakas (ferrous sulphate or green vitriol), Fitkari (alum), Shora (potassium nitrate or saltpetre), Suhaga (borax), Tinta or Multani (copper sulphate), and many organic acids and bases were prepared and used in medicines. They even could prepare nitric acid by reacting Hirakas with Shora.
Many such accounts of the chemistry of the bygone past are stored in books like, “A history of Hindu chemistry from the earliest times to the middle of the 16th century, A.D.,” by Acharya P. C. Roy; “Rasa Ratnakararam,” by Siddha Nitya Nath, with volumes “Rasa,” “Rasayana,” and “Ridhi”; “Rasaratna Samuccaya of 13th, 14th, or 16th century A.D.,” by Baghbhatta; “Ayurveda Prakasa,” by Sri Madhava Upadhyaya; “Rasa Hriday tantra of 6th or 7th century A.D.,” by Govindapadadeva; “Rasasaram,” by Govindacharya; “Rasapadhadi,” by Bindu; “Dhaturatnamala,” by Devadatta; “Lohasarvasvam,” by Suresvara; and “Rasendra Chintamani,” by Dundukanatha.