History of Chemistry in Ancient and Medieval India, Incorporating the History of Hindu Chemistry by Acharya Prafulla Chandra Ray c40.s2.13

c40.s2.13

The magnitude of *paramanu* is called *parimandalya* in the Nyaya-Vaiseshika, the name suggesting that the *paramanus* were conceived to be spherical in shape. The Nyaya-Vaiseshika calls a *paramanu* a mere point without any dimensions, but in the Samkhya-Patanjala, a *paramanu*, though indefinitely small, had still dimensions, being divisible into *tanmatras*, which were themselves integrations of *bhutadi*. The diameter of a spherical *paramanu* must have been conceived to be less than 3 × 2⁻²⁰ of an inch (i e., less than the conventional *paramanu* with which linear measures begin), and the volume of a *paramanu* would, therefore, in accordance with Bhaskara's formula, be smaller than 4/3π × 3³ × 2⁻⁶³ or π × 3³ × 2⁻⁶¹ of a cubic inch. The *tanmatras* were conceived as smaller still.