Kautilya's Arthashastra 4.7.13

4.7.13

hṛdayād uddhṛtyāgnau prakṣiptaṃ ciṭiciṭāyadindradhanurvarṇaṃ vā viṣayuktaṃ vidyāt, dagdhasya hṛdayam adagdhaṃ dṛṣṭvā vā //

In death due to poison, the undigested portion of meat may be examined in milk. Or the same extracted from the belly and thrown on fire may, if it makes ‘chitchita’ sound and assumes the rainbow colour, be declared as poisoned.

Or when the belly (hridayam) remains unburnt, although the rest of the body is reduced to ashes, the dead man's servants may be examined as to any violent and cruel treatments they may have received at the hands of the dead. Similarly such of the dead man's relatives as a person of miserable life, a woman with affections placed elsewhere or a relative defending some woman that has been deprived of her inheritance by the dead man may also be examined.