Hydriodic acid, its electrolyses

Hydrocyanic acid, its electrolyses

Hydrofluoric acid, not electrolysable

Hydrogen, brush in

—— positive and negative brush in

—— —— discharge in

Hydrogen and oxygen combined by platina plates

—— spongy platina, .
Ice, its conducting power

—— a non-conductor of voltaic currents

Iceland crystal, induction across