As per Hindu philosophy, Pitharapakavada is the heating of molecules. According to Hindu philosophers, matter is divided into five kinds – prithvi (earth), ap (water), agni (fire), vayu (air) and akasha (ether), each of which consists of anus (atoms). While the atoms of ether remain as such, the atoms of the other four forms of matter combine together to form molecular units of dvyanuka (two atoms), traynuka (three atoms), caturanuka (four atoms) and so on. Atoms and molecules also have a tendency to unite to form substances of innumerable kinds as found in the world, each differing from one another in the matter of smell, taste, heat and touch, which are the basic qualities of the four primary elements. The atoms are also supposed to possess an incessant vibratory motion, which gives them the tendency to combine together to form molecules of the same element or with the atoms of other elements. According to the Nyaya and Vaiseshika schools, a substance produced by the combination of