INDIGO WHITE

Syn. Indigo gene , Indicyle , Reduced indigo , Hydrogenised i. , Hydrate of i . Reduced or deoxidised indigo blue. Prep. The yellow alkaline solution obtained by one or other of the proce es noticed under Indigotin is carefully protected from the air, both before and after precipitation with hydrochloric acid; and the precipitate, after being rapidly washed with recently boiled distilled water, or with very dilute sulphurous acid, is drained on a filter, dried in vacuo, and then at once transferred to a well-stoppered bottle. Prop., . A greyish-white ma of minute crystals, generally light blue on the surface, and rapidly turning blue on exposure to the air; soluble in alkalies, alcohol, and ether, to which it imparts a yellow colour. These solutions deposit indigo blue on exposure to the air. A solution of this substance constitutes the indigo vat of the dyer (see above ).