CHROMIC ACID.—This is an anhy dride, fonnd as brilliant, crimson-red, acicular, deliquescent crystals that are most freely soluble in water. It is pre pared by mixing a solution of potassium bichromate with sulphuric acid, reject ing the crystals of acid sulphate of potas sium which crystallize out, heating the liquor, and adding more sulphuric acid, when the chromic acid is formed by crystallization. It is also soluble in ether that is free from alcohol and water. It is decomposed by most acids—lactic, sulphurous, hydrosulphuric, h y dr o chloric, arsenous, etc.; by glycerin; and is likely to cause explosion if mixed with the latter or with alcohol.
Preparations and Doses. — Chromic anhydride (chromic acid), external use only.
Chromic-acid liquor (1 part to 3 of distilled water), external use only.
Physiological Action.—Chromic acid possesses the power of killing all low organisms, oxidizing organic matter, coagulating albumin, and destroying the tissues with which it conies in contact. It is thus antiseptic, disinfectant, and powerfully caustic. Made into a paste with water, its action is exceedingly slow and gradual, but deeply penetrating; in saturated solution it is less penetrating and slower in action. By employing a
solution more or less dilute, the action may be graduated according to the ef fects desired. Death has resulted from absorption when it has been applied too freely. Its local effects are, for the most part, antagonized by bland neutral fats, applied in excess. The toxic effects are similar to those of potassium bichro mate.
Therapeutics. — AS AN ANTISEPTIC AND DISINFECTANT.—TWO draChMS of chromic anhydride added to 4 or 5 quarts of water gives an inexpensive, but efficient, antiseptic and disinfecting lotion for leucorrhceas, omnas, hyperi drosis, putrid sores, etc.; a lotion of 10 grains to the ounce has a decided effect upon syphilitic, gouty, and kindred maladies of tongue and throat. As a local application to cancerous and other ulcerations, it is preferable to all other caustics, since the pain attendant on its application is trifling; but it must be used cautiously and discriminatingly.