History of Chemistry in Ancient and Medieval India, Incorporating the History of Hindu Chemistry by Acharya Prafulla Chandra Ray c40.s5.14

c40.s5.14

A small bladder made of thin membrane, filled with air, will not cause a greater descent in the scale of a balance than the same bladder weighed empty. Hence, the air possesses no weight. Then Udayana makes an interesting statement. It may be objected, he says, by one who accepts the weight of air—that this argument is inconclusive. For, a counter-experiment may be suggested. The balloon filled with smoke (or gas—*dhum*) rises in the air, whereas the air-filled balloon comes down. This would go to show that air has weight. Udayana replies that this would only show that both smoke and air have no weight. The Hindus appear to have been ignorant of the principle of Archimedes, at least as applied to gases. Vallabhacharya in the Lilavati speaks of a peculiar resistance to sinking exercised by water, which explains the tendency in certain objects to float or to come up to the surface of the water: but the description shows that he had no clear ideas on the subject (*cf*. Udayana, Kiranavali—*vayu-nirupanam*).