What is "cadet's fuming liquid"

Fuming \Fum"ing\, a. Producing fumes, or vapors.

Cadet's fuming liquid (Chem.), alkarsin.

Fuming liquor of Libavius (Old Chem.), stannic chloride; the chloride of tin, SnCl4, forming a colorless, mobile liquid which fumes in the air. Mixed with water it solidifies to the so-called butter of tin.

Fuming sulphuric acid. (Chem.) Same as Disulphuric acid, uder Disulphuric.

Cadet's fuming liquid was the first organometallic compound to be synthesized. In 1760, the French chemist Louis Claude Cadet de Gassicourt (1731-1799) synthesized a red liquid by the reaction of potassium acetate with arsenic trioxide.

4 KCHCOO + AsO → As(CH) + 2 KCO + 2 CO + 1/2 O

The liquid contains a mixture of cacodyl and cacodyl oxide. These were the first organometallic substances prepared, so Cadet can be regarded as the father of organometallic chemistry.