Anandakanda 1.6.114

1.6.114

vā stanena ca tanvaṅgyā nirvyathaḥ kramate rasaḥ /
<saptadhātuvedhaḥ>
tvagvedhaḥ prathamaṃ devi raktavedho dvitīyakaḥ //

Or with the breast of a slender-limbed woman; [then] the mercury permeates free of pain. / <Transmutation of the Seven Tissues> / Transmutation of the skin is the first, O Goddess; transmutation of blood is the second;