The Positive Sciences of the Ancient Hindus c5.s4.6

c5.s4.6

In evaporation the fluid-particles are rarefied, and remain in a fine state of suspension; the rarefaction is due to the impulse (नोदन) or impact (अभिघात) of the heat-particles in the sun's rays, and the upward movement is due to their contact with the air under this impulse or impact. Śankara Miśra notes that in boiling there is a similar upward movement of water-particles under the impact of heat-rays. (नाड्यो वायसंयोगात् आरोहणं नोदनापीडनात् संयुक्तसंयोगात् च । Sûtras 5 and 6, Âhnika 2, Chap. 5, Vaiśeṣika Aphorism. यथा स्थालीस्था आपः क्कथ्यमानाः वायुनुन्नवह्नि-रश्मय ऊर्ध्वं नयन्ति—Śankara Miśra, उपस्कार ।)