Physics and chemistry

The so-called Vaiśeṣika school, which emerged in the first millennium before the Christian era, claims that matter consists of indestructible atoms assembled into molecules, but it is more concerned with metaphysics than with physics, which was neglected by the ancient Indians. As for chemistry, it was initially used for therapeutic purposes. One branch of Ayurvedic medicine, rasaśāstra, combines mercury (rasa) with metals such as gold, silver and lead, animal matter and plants to produce long-lasting medicines and remedies. The term rasāyana refers to the quest for immortality and, by extension, the alchemy that is the means to achieve it. Marco Polo attributed the extraordinary longevity of the Yogis to their healthy and frugal diet, but also to a drink containing mercury: "For I assure you that they take quicksilver and sulphur and mix them together to make a drink, which they then swallow. They say it prolongs life, and so they live all the longer. I can tell you that they take it twice a month. You should know, too, that these people start taking this drink from childhood in order to live longer. And certainly those who live to the age I have mentioned take this drink of sulphur and quicksilver." Eternal youth (dehavāda) was not the only pursuit of Indian alchemists, whose research also focused on the conversion of lower metals into precious metals (lohavāda).

The two great physicians of the first centuries of our era, Suśruta and Caraka, excelled in the chemical preparation of medicines based on mercury, precious and non-precious metals, sulphur, pyrite, and so on. Among other things, they developed mercury-based ointments for skin diseases and an anti-diabetic "syrup" made by macerating iron salts with plants, which is still used in Ayurvedic medicine today. The ancient Indians also used chemical processes to make caustic detergents.

Indians mastered metalworking very early on: wootz is a high-carbon crucible steel that first appeared in India around 300 BC. Very popular throughout the Ancient Orient, it was used to make sabre blades, particularly Damascus blades. Delhi’s seven-metre-high, six-tonne Mehrauli Iron Pillar is a testament to the mastery of the Gupta metalworkers: it has endured around 1,600 monsoons and has not been altered or corroded in any way. It contains over 99% iron, a level not achieved in the West until the 19^th century. In 2002, Professor R. Balasubramaniam from the Indian Institute of Technology in Kānpur discovered the existence of a protective film formed by catalysis during the smelting of iron with charcoal, which releases phosphorus.

Science had already been cultivated in India for thousands of years before the Europeans began to settle there. The missionaries discovered "an astonishing aptitude and eagerness for study" in their students. In the great colleges they founded in the 19^th and 20^th centuries, the Jesuits helped to unleash scientific capacities that had lain dormant since the beginning of the second millennium. Recognising India’s "extraordinary potential in mathematics", Father Racine (1897-1976), who taught at Saint Joseph’s College in Trichinopoly (now Tiruchirappalli) and then at Loyola College in Madras (now Chennai), trained some of the greatest Indian mathematicians of the 20^th century.

Published in july 2024