Nessler's reagent

Tests.—Nessler's reagent is the most delicate, a reddish-brown colour or precipitate being produced, but ammonia may be recognized by its pungent odour, dense fumes given off with hydrochloric acid, and strong alkaline reaction.

This is effected by means of "Nessler's" reagent, which strikes a brown colour with traces of ammonia, even with a few hundredths of a milligram in 100 c.c. of liquid.

Fifty c.c. of it are transferred to a Nessler glass and mixed with 2 c.c. of Nessler's reagent.

Ammonia, almost always present in distilled and rain water Brown coloration, or precipitate with Nessler's reagent.