Gold, Ammoni′uret of

Syn. Aurate of ammonia , Berthollet’s fulminating gold ; Aurum ammonia tum , Ammoniæ auras , L. Prep. By adding ammonia to a solution of gold in aqua regia (trichloride), as long as a reddish-yellow precipitate (fulminating gold) forms; the latter must be collected, washed, and dried with the greatest po ible caution. Obs. Ammonia fails to precipitate trioxide of gold from solutions which are not tolerably concentrated, and in those containing free acid or ammoniacal salts the precipitate only forms upon boiling the solution. Before adding the ammonia, it is, therefore, proper to drive off the exce of acid, if any, by the application of heat. See Fulminating Compounds .