Rasayana

Rasāyana, रसायन is a Sanskrit word, with the literal meaning: Path (āyana) of essence (rasa). It is a term that in early ayurvedic medicine means the science of lengthening lifespan, and in later (post 8th-century) works sometimes refers to Indian alchemy.

The name of the science of Indian alchemy or proto-chemistry, is more generally "The Science of Mercury", or Rasaśāstra, रसशास्त्र in Sanskrit, Nepali, Marathi, Hindi, Kannada and several other languages. Early Indian alchemical texts discuss the use of prepared forms of mercury or cinnabar (see samskaras). However, there is also ample mention of the preparation of medical tinctures in the early science of Indian alchemy.

Significant progress in alchemy was made in ancient India. Will Durant wrote in Our Oriental Heritage:

"Something has been said about the chemical excellence of cast iron in ancient India, and about the high industrial development of the Gupta times, when India was looked to, even by Imperial Rome, as the most skilled of the nations in such chemical industries as dyeing, tanning, soap-making, glass and cement... By the sixth century the Hindus were far ahead of Europe in industrial chemistry; they were masters of calcinations, distillation, sublimation, steaming, fixation, the production of light without heat, the mixing of anesthetic and soporific powders, and the preparation of metallic salts, compounds and alloys. The tempering of steel was brought in ancient India to a perfection unknown in Europe till our own times; King Porus is said to have selected, as a specially valuable gift from Alexander, not gold or silver, but thirty pounds of steel. The Moslems took much of this Hindu chemical science and industry to the Near East and Europe; the secret of manufacturing "Damascus" blades, for example, was taken by the Arabs from the Persians, and by the Persians from India."

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