Definition of Nessler's reagent in English:

Nessler's reagent

(also Nessler reagent)

noun

Chemistry
  • An alkaline solution of mercuric iodide and potassium iodide, containing HgI₄ 2− ions, which gives a brown colour or precipitate when added to an aqueous solution containing ammonia. Similarly "Nessler('s) solution".

Origin

Mid 19th century; earliest use found in Journal of the Chemical Society.