History of Chemistry in Ancient and Medieval India, Incorporating the History of Hindu Chemistry by Acharya Prafulla Chandra Ray c14.s1.18

c14.s1.18

*Akasa* (ether), according to Kanada, has no atomic structure; it is inert and ubiquitous serving only as the substratum of sound which is supposed to travel in the form of waves in the manifesting medium of *vayu* (air). Samkhya too conceived of *akasa* as the universal all-pervading medium in which air, light and heat corpuscles, and other atoms move and float about. Kanada, therefore, recognised four kinds of atoms; viz., the *kshiti*, the *ap*, the *tejas* and the *vayu* atoms, which correspond to the atoms of four gross elementary types of matter,—earth, water, fire and air, as taught by the Greek philosophers Regarding light and heat Kanada makes the remarkable statement that they are only the different forms of one and the same essential entity, *tejas* Kanada attributes to these atoms certain characteristic properties, such as number, quantity, individuality, mass, gravity, fluidity, velocity, elasticity, as well as certain characteristic potentials of sense stimuli like colour, taste, smell or touch According to him atoms are eternal and indestructible, though they cannot exist in free or uncombined state. As an aggregate or in the combined state they are, however, transient The qualities of *kshiti* are colour, taste, smell and touch, the distinguishing quality is, however, smell. *Ap* has the qualities of *kshiti* excepting smell and with the addition of viscidity, its distinguishing quality is coolness. *Tejas* has the qualities of *kshiti* excepting smell, taste and gravity; its distinguishing quality is colour and hotness. *Vāyu* has the qualities of *kshiti* with the exception of smell, taste and colour; its distinguishing quality is touch.