Contractions. - Cinnab. Cnb.

Synonyms. - Cinnabar, Vermilion.

Present name. - Mercuric Sulphide. HgS.

This is prepared by sublimation of a mixture of 6 parts of metallic Mercury and 1 part of the Flowers of Sulphur, and may be obtained from the operative chemists as Vermilion.

Characters and Tests. - A heavy powder of a splendid red tint intermediate between crimson and scarlet. It is without taste or odour, and does not undergo change in the air. When gently heated it assumes a dull brownish-red colour, which, if the heat be continued, becomes nearly black, but recovers its red colour on cooling. At a higher temperature it takes fire if exposed, but in a tube it sublimes unchanged. If ignited with fixed alkalies or their carbonates, metallic Mercury sublimes.

Preparation. - Trituration.

Reference to Horn. Proving. - R. A. M. L., i. N. A. Journ. of Horn., Appx.

Proper forms for dispensing. - lx to 3, Trituration only. 4, dilute Tincture only. 5 and upwards, Tincture, Pilules, or Globules.