| 204 / | HD | CHEMISTRY: ELECTRICAL AND WAVE ENERGY |
| 193 | DF | APPARATUS {5} |
| 194 | DF | .~ Electrolytic {11} |
| * | DD | .~.~ With movable electrode means {7} |
| 206 | DF | .~.~.~ Continuous strip or filament electrode {2} |
| 207 | DF | .~.~.~.~ With base treatment {3} |
| 209 | | .~.~.~.~.~ Mechanical working |