In Germany the high pressure (intermittent) apparatus have acid feeders attached of the type represented by the appended illustration, which shows Illner's Patent Acid Feeder. It is made partly of glass and partly of metal and is much recommended, a, iron bolts, connecting bottom and top b and c, consisting of metal plates and lined on the inside with hard rolled lead, d is a cylinder of very heavy and thick glass, open on both ends and air tight, connected with the metal plates, e, inlet for acid. f, a screw arrangement for regulating the valve, which closes the heavy leaden tube g. The latter leads the acid into the generator. Tube h with cock serves as pressure equalizer. At i the acid feeder may be secured to the wall. A similar pattern is represented next.

Fig. 221.   Illner's Acid Feeder

Fig. 221. - Illner's Acid Feeder.