Arthashastra
मनुष्याणाम् अक्ष मात्रम्, गव अश्वानां द्वि गुणम्, चतुर् गुणं हस्त्य् उष्ट्राणाम् ॥
The proportion of a dose is as much as an aksha (?) to men; twice as much to cows and horses; and four times as much to elephants and camels.
english translation
manuSyANAm akSa mAtram, gava azvAnAM dvi guNam, catur guNaM hasty uSTrANAm ॥
hk transliteration by Sanscript