Gold may be removed from gilded silver by the following method. Mix together, in an earthenware, porcelain, or enamelled iron cup, 4 parts hydrochloric acid (spirit of salts), I part of nitric acid (aquafortis), and 1 part water. Make warm, and place the vessel on a hob in a fireplace with a good draught to carry off the fumes. Dip the silver articles one by one in the mixture until nil the gold has been dissolved; then rinse well in clean water and rub in sawdu t or bran until dry.

Fig. 3. Under-carriage for 'Bus.