Purification of Water.
The water used in this work was purified by distilling twice from an alkaline solution of potassium permanganate, always rejecting the first part of the distillate. Whenever water was needed in the preparation of a pure compound e.g. cadmium oxalate, oxalic acid, cadmium nitrate, etc., it was subjected to the additional process of being distilled against a large platinum dish which was kept cool by placing ice inside it.