Contractions. - Merc-biniod. Mr-b.

Synonyms. - Mercurius Biniodatus, Hydrargyri Iodi-dum Rubrum (P.B.).

Present name. - Mercuric Iodide. Hgl2.

Red Iodide of Mercury.

This may be made as follows: -

Take of

Perchloride of Mercury . . . .

4 ounces;

Iodide of Potassium . . . .

5 ounces;

Boiling Distilled Water . . . .

4 pints.

Dissolve the Perchloride of Mercury in 3 pints of the water, and the Iodide of Potassium in the remainder, and mix the solutions. Having allowed the mixture to cool, collect the precipitate on a calico filter, wash it thoroughly with distilled water, and dry on a water-bath.

Characters and Tests. - A crystalline powder of a vermilion colour, becoming yellow when gently heated over a lamp on a sheet of paper; almost insoluble in water, dissolves sparingly in alcohol, but freely in ether or in an aqueous solution of Iodide of Potassium. When digested with solution of Soda it assumes a reddish-brown colour, and the fluid, cleared by filtration and mixed with solution of Starch, gives a blue precipitate on being acidulated with Nitric Acid. Entirely volatilized by a heat under redness.

Mercury, by weight . . .

1 ounce;

Iodine .....

278 grains;

Rectified Spirit ....

A sufficiency.

Preparation. - Trituration.

Reference to Horn. Proving. - Hering's New American Materia Medica.

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