What is "cacodyl oxide"

n. (context organic chemistry English) A strong-smelling liquid, ((CH₃)₂As)₂O

Cacodyl oxide is a chemical compound of the formula [(CH)As]O. This organoarsenic compound is primarily of historical significance as it is sometimes considered to be the first organometallic compound synthesized in relatively pure form.

" Cadet's fuming liquid", which is composed of cacodyl and cacodyl oxide, was originally synthesized by heating potassium acetate with arsenic trioxide. It has a disagreeable odor and is toxic. It has been used as a denaturing and warning agent.