Cr.=52.0.

1. Acidum Chromicum. Chromic Acid

Acidum Chromicum. Chromic Acid. CrO3=99.88. Synonyms. - Chromic Anhydride. Chromic Trioxide.

Source

Dissolve Potassium Dichromate in Sulphuric Acid and water, decant from the Acid Potassium Sulphate, heat with more Sulphuric Acid, cool and crystallize. K2Cr2O7+2H2So4=2CrO3+2Khso4+H2O.

Characters

Small needle shaped crystals, or rhombic prisms, of a dark purplish-red color and metallic lustre. Readily yields Oxygen, and will, therefore, easily explode, with either Glycerin, Ether, or Alcohol. Solubility. - Very soluble in water.

Action of Chromic Acid

External

In consequence of its oxidizing power, chromic acid is a powerful deodorant and disinfectant. It coagulates albumin and oxidizes organic matter, and is therefore a powerful caustic.

Internal

None is known.

Therapeutics of Chromic Acid

External

It is used generally in the strength of 1 per cent. to harden catgut and kangaroo tendon for surgical uses. A lotion of the same strength is used in Germany to toughen the feet of marching soldiers. As a lotion, 1 to 40, or even stronger, chromic acid has been used for its disinfectant properties to wash foul ulcers and sores, and also as a local application for ozaena, gonorrhoea, leucorrhoea, and bad ulcerations of the mouth, but a gargle should not be stronger than 1 to 480. The Liquor of the B. P., which is one part of chromic acid in 3 of water, is occasionally used as a caustic to destroy condylomata, etc.

2. Potassii Bichromas. Potassium Bichromate

Potassii Bichromas. Potassium Bichromate. K2C2O7= 293.78. Synonym. - Potassium Dichromate.

Source

Finely-ground Chrome-iron ore mixed with Potassium Carbonate is roasted in a reverberatory furnace, which causes the separation of all iron in the form of Ferric Oxide, and the production of Potassium Bichromate. Lime or chalk is added during the roasting to prevent fusion. 2FeOCr2O3+ 4K2Co3+4O2=Fe2O3+4K2CrO4+4Co2. After solution in water Sulphuric Acid is added, and the two salts are separated by crystallization. 2K2CrO4+ H2So4=K2Cr2O7+K2So4+H2O.

Characters

Large, orange-red, transparent, triclinic prisms or four-sided tables, odorless, and having a bitter, metallic taste. Solubility. - In 10 parts of water; insoluble in Alcohol.

Incompatibles

Owing to the ease with which it oxidizes it readily forms explosive compounds. It is here prescribed as a pill made up with kaolin. Impurities. - Sulphates, chlorides and calcium. Dose, 1/10 to 1 gr.; .006 to .06 gm.

Action of Potassium Bichromate

External

It is an irritant caustic Handling the salt may produce eczema.

Internal

Occasionally solutions of it have been taken by mistake. Symptoms of very severe gastro-intestinal inflammation with much collapse have followed.

Therapeutics of Potassium Bichromate

External

It is used as a caustic for warts, venereal ulcers and mucous patches. Its solution is caustic and antiseptic, but it is weaker than chromic acid.

Internal

It has been recommended for the treatment of gastric catarrh and gastric ulcer in dose of from 1/12 to 1/6 gr., .005 to .01 gm., given thrice daily on an empty stomach, and is reputed to relieve nausea, vomiting and pain.

The remaining groups of the inorganic drugs are non-metallic.