Contractions. - Kali-bich. K-bi.

Present name. - Potassic Dichromate. K2Cr2O7.

This is the well-known Bichromate of Potash which is used so largely in dyeing. It may be obtained from the manufacturing chemists, and be purified by dissolving in hot distilled water and allowing it to crystallize.

Characters and Tests. - Red, transparent, anhydrous, four-sided tables, soluble in water. The aqueous solution becomes green when mixed with Hydrochloric Acid and an excess of Sulphuretted Hydrogen.

Preparations. - Solution in distilled water, 1 in 20. Trituration.

The 1 attenuation is made with distilled water; 3x to 3 with distilled water to which 5 per cent. of rectified spirit has been added; 7x and 4 with dilute alcohol; and all above with rectified spirit.

N.B. - The liquid attenuations should not be made from the triturations, as a partial decomposition takes place after some time.

Reference to Horn. Proving. - Hahn. Mat. Med.

Proper forms for dispensing. - lx, Trituration only. 1 in 20 Solution. 1 to 3, Trituration or Solution. 4, dilute Tincture only. 5 and upwards, Tincture, Pilules, or Globules.