The latex coagulates readily, especially if churned or if diluted with water, when a purer rubber is obtained.
It is prepared by oxidizing potassium ferrocyanide with a diluted nitric acid.
The first is formed when 30% hydrogen peroxide reacts with phosphorus pentoxide or metaor pyrophosphoric acids at low temperatures and the mixture diluted with ice-cold water.
One part of quicklime is slaked with 6 parts of water, and the paste produced diluted with 24 parts of water; 2.3 parts of flowers of sulphur are added; and the whole is boiled for about an hour or longer, when the sulphur dissolves.
The mixed solution of poiysulphides and thiosulphate of calcium thus produced is clarified, diluted largely, and then mixed with enough of pure dilute hydrochloric acid to produce a feebly alkaline mixture when sulphur is precipitated.