The Positive Sciences of the Ancient Hindus c4.s6.4

c4.s6.4

The four kinds of Atoms are Earth, Ap, Tejas, and Váyu atoms, possessed of characteristic mass, numerical unit, weight, fluidity (or its opposite), viscosity (or its opposite), velocity (or quantity of impressed motion—Vega); also characteristic potential colour, taste, smell, or touch, not produced by the chemical operation of heat (अपाकजरूपरसगन्धस्पर्शपरिमाणैकत्वैकपृथक्त्वगुरुत्वद्रवत्वस्नेहवेगाः). Ákása has no atomic structure (निरवयव), and is absolutely inert (निष्क्रिय), being posited only as the substratum of sound, which is supposed to travel wave-like in the manifesting medium or vehicle of Váyu (air). Only the other four Bhútas unite (or disunite) in atomic or molecular forms. The orthodox view is that the presence of Earth-atoms is necessary whenever chemical transformation under the operation of heat (पाकजोत्पत्ति) takes place.