Arthashastra
कृष्ण चतुर्दश्यां शस्त्र हताया गोः कपिलायाः पित्तेन राज वृक्षमयीम् अमित्र प्रतिमाम् अञ्ज्यात्, अन्धी करणम् ॥
When the figure of an enemy carved out of rájavriksha (cassia fistula) is besmeared with the bile of a brown cow killed with a weapon on the fourteenth day of the dark half of the month, it causes blindness (to the enemy).
english translation
kRSNa caturdazyAM zastra hatAyA goH kapilAyAH pittena rAja vRkSamayIm amitra pratimAm aJjyAt, andhI karaNam ॥
hk transliteration by Sanscript