The Ph. Grca orders infusion of galls to be used as the precipitant.

The degree of separation of water (spent lye) depends upon the amount of precipitant used.

However, the appearance of the new arrival greatly modified the unfavorable impression produced by his precipitant action.

Potassium hydrate and ammonia give black grey or black precipitates, which are insoluble in excess of the precipitant.

Ammonia gives a similar precipitate, which is soluble in excess of the precipitant.

A solution of potassa causes a white granular precipitate of cream of tartar, soluble by agitation in excess of the precipitant.

This method has the advantage of the water being perfectly freed from any excess of the precipitant by heat.

The acid curd then is casein or some combination of casein with the precipitant acid.

This distinguishes it from zinc, which gives a similar white precipitate, but is soluble in the excess of the precipitant.

Given such a precipitant, the process of recovering the gold would be simple and cheap.