The Positive Sciences of the Ancient Hindus c4.s6.26.4

c4.s6.26.4

or, as with light-rays in cases of translucency or transparency (स्वच्छता), penetrate through the inter-atomic spaces with Parispanda of the nature of deflection or refraction (तिर्य्यग्गमन, Udyotakara), in the same way as when fluids penetrate through porous bodies (तत्र परिस्पन्दः तिर्य्यग्गमनं परिस्रवः पात इति—Udyotakara, commenting on Vátsyáyana's परिस्पन्दपरिस्रवौ, Sutra 47, Áhnika 1, Chap. III.); or (2) impinge on the atoms, and rebound back—which explains reflection (मूर्च्छेन, किरणविघट्टन—Varáhamihira, रश्मिपरावर्त्तन—Vátsyáyana), or otherwise be obstructed by the atoms in their path, which would explain degrees of opacity, the casting of shadows, etc., all these operations being also physical, and unattended by decomposition and recomposition or alteration of molecular grouping; or (3) lastly, strike the atoms in a peculiar way, so as to break up their grouping, transform the physico-chemical characters of the atoms, and again recombine them, all by means of continual impact with inconceivable velocity, an operation which explains all cases of chemical combination. (अचिन्त्यो हि तेजसो लाघवातिशयेन वेगातिशयः यत् प्राचीनाचलचूड़ावलम्बिनि एव भगवति मयूखमालिनि भवनोदरेषु आलोकइत्यभिमानो लौकिकानाम्।—Udayana, Kiranávalí, तेजोनिंरूपणम्, taken from Váchaspati, Tátparyyatíká, प्रत्यक्षलक्षणसूत्रम्। *Cf.* also चाक्षुषं तेजः वेगवता सावित्रेण तेजसा न प्रतिहन्यते।—Váchaspati. वर्त्तिदेशे पिण्डितमपि तेजः प्रसर्पत् प्रासादोदरं व्याप्नोति। तत् कस्य हेतोः पृथुयत्वात्।