Method of Experiment.—Weighed quantities of other metals will be added to weighed quantities of silver and lead, and after cupellation the coloration of the cupel and the appearance of the bead indicate to a certain extent the impurity present.
Apparatus.—The muffle furnace, balance, and accessories.
Reagents, etc—Gold, silver, lead, copper, tin, antimony.
Details of Experiment.—Weigh out five charges approximately as follows:—
Wrap each of these live charges in 5 gm. sheet lead, and cupel at a bright red heat. Tabulate results as follows:—
In his subsequent work the student will gain further experience in the effects of these and other impurities on cupellation, and also as to the effects of varying quantities of one and the same impurity.