Page:The British pharmacopœia.djvu/512

478 SULPHIDE OF IRON.

FeS.

Prepared by combining its elements in proper proportions by the aid of beat. Small quantities may be produced by applying the end of a rod of iron, heated to whiteness at a blacksmith's forge, to the end of a roll of sulphur, and allowing the sulphide of iron as it is formed to run into a vessel of water,

SULPHURETTED HYDROGEN.

H2S.

Take of

Place the sulphide of iron and the water in a gas-bottle closed with a cork perforated by two holes, through one of which passes air-tight a funnel tube of sufficient length to dip into the water, and through the other a tube for giving exit to the gas. Through the former pour from time to time a little of the acid, so as to develope the sulphuretted hydrogen as it may be required.

When the gas is employed, either in chemical testing or in the preparation of Acidum Hydrobromicum Dilutum, it should be washed by passing it through a similarly fitted bottle containing water.

TIN, GRANULATED.

Grain tin, reduced to small fragments by fusing and, immediately the tin is melted, pouring it in a thin stream into cold water.

TURMERIC.

The dried rhizome of Curcuma longa, Linn.

TURMERIC PAPER.

Unsized white paper steeped in tincture of turmeric and dried by exposure to the air.