sal ammoniac

Rub thoroughly with strong brine, or a solution of sal ammoniac dissolved in eight times its weight of water.

It absorbs one-sixth more than its bulk of alkaline air, and with it forms the common sal ammoniac.

Platina is precipitated from a solution in aqua regia by sal-ammoniac, as gold is by martial vitriol.

Instead of the solution of sal-ammoniac equal parts of water and hydrochloric acid saturated with zinc can be used just as well.

Then put in a crumb of sal-ammoniac and fill up with water and it is ready for use.