The Positive Sciences of the Ancient Hindus c4.s2.36

c4.s2.36

*Chemistry of Colours.*—As an interesting example of the way in which a follower of Charaka would account for the colours of chemical compounds, I may note the explanation given by the late Gańgádhara Kavirája Kaviratna in the Jalpakalpataru, a commentary on the Charaka-Samhitá, published at Calcutta in 1869, premising that the Kavirája's view is pure and genuine Charaka doctrine. Gańgádhara begins with a simple statement. The qualities of the atom, he writes, tend to produce similar qualities in the molecule. A molecular quality is therefore the result of the conjunction or opposition, as the case may be, of the atomic tendencies. When, for example, the five Bhútas combine to produce an organic compound (the human body), Tejas, Ap, and Earth tend to produce red, white, and black respectively, but in the body (compound substance) the yellow colour may happen to be produced as the result of these tendencies in that particular proportion and collocation. The point to note here is that the molecule forms a fresh collocation, *redistributes the Mass and Energy*, and sets up new forces in the system, which coming into play modify the potencies (or tendencies) in the component atoms, and thus determine the resultant. This is elaborated into a curious but complete theory of the colours of chemical compounds.