Rasarnava 7.39

7.39

kālakūṭaviṣaṃ pītvā garuḍaḥ soḍhumakṣamaḥ
sudhāmapi tathāvāmat bhukta āśīviṣāmṛte
svayaṃ vinirgate cañcvoḥ sasyako 'bhūt sa kālikaḥ //

Garuḍa, having drunk the kālakūṭa poison, being unable to bear it,
also vomited nectar; the snake and the nectar having been consumed,
when it emerged spontaneously from his beak, that became blue vitriol, dark blue in color.