The Collaborative International Dictionary
Polychromatic acid
Polychromatic \Pol`y*chro*mat"ic\, a. [Poly- + chromatic.] Showing a variety, or a change, of colors.
Polychromatic acid (Old Chem.), a substance obtained by the action of nitric acid on aloes.
Wiktionary
polychromatic acid
n. (context chemistry English) A substance obtained by the action of nitric acid on aloes.