This section is from the book "Dental Medicine. A Manual Of Dental Materia Medica And Therapeutics", by Ferdinand J. S. Gorgas. Also available from Amazon: Dental Medicine.
Chromic acid is obtained in the form of brilliant, deep red, acicular crystals, by the reaction of strong sulphuric acid upon a solution of bichromate of potash. It is deliquescent, and very soluble in water and alcohol, forming an orange-yellow solution.
Medical Properties and Action - It is a powerful caustic, decomposing the tissues by rapid oxidation; and although it is very slow and gradual in its action, yet it is deeply penetrating and when its action ceases, sesquioxide of chromium remains. So destructive is its effect, that small animals are dissolved entirely, bones and all, by it, in fifteen or twenty minutes. On account of its penetrating deeply, without much pain, care is necessary in its use ; and when used as a caustic, the surrounding tissues should be well protected. The part on which it acts first becomes yellow, then brown, and ultimately black, and the eschar is detached in from twenty-four to forty-eight hours. It is a powerful oxidizer, and gives up its oxygen readily to organic matter, which it thus dissolves. When in solution, more or less diluted, its action can be modified, according to the effect desired.
Chromic acid is not given internally. In the form of paste, or solution with water, it is a valuable caustic in cancerous and other ulcerations, malignant growths, hemorrhoids, warts, etc. Chromic acid has been employed with good effect in syphilitic sores, cases of secondary syphilis, deep and jagged ulcers of the tongue, and ulceration of inside of the cheek, mucous tubercles and condylomata. It has also been employed in the treatment of granular ophthalmia, uterine hemorrhage, uterine catarrh, etc. It causes less pain than nitric acid and other caustics, and should never be applied to a surface to be cauterized in a layer deeper than a line in thickness. For removal of warts, etc., it is employed in a solution of 100 grains to the ounce of distilled water.
In dental practice chromic acid has been employed for obtunding sensitive dentine; but its most valuable application is for the removal of tumors and morbid growths upon the gums, fungous growths of tooth pulp, etc. When applied to any part of the mouth, the surrounding parts should be carefully protected by folds of lint or strips of adhesive plaster, or the rubber dam. A glass rod, or a gold or platinum wire, should be used for its application. It is also useful in ulceration and recession of the gums, beginning the treatment with a weak solution, and gradually increasing the strength. It is sometimes combined with glycerine, in which case the latter must be added to the acid drop by drop, in order to avoid explosion. As an obtundent it is useful in the strength of a solution I in 40, for relieving the pain of psoriasis and syphilitic affections of the tongue.
For Secondary Syphilitic Ulcers, and Ulceration of Mucous Membrane of Mouth and Tongue.
Paint the diseased parts 3 or 4 times a day, with a cam-el's-hair brush dipped in the solution.