Kalium bichromicum: keynotes and materia medica
Kalium bichromicum — the homeopathic preparation of potassium dichromate — has one of the easiest keynotes in the materia medica to recognise: a discharge so tough and stringy that it can be drawn out into long threads. Reach for it when thick, ropy, yellow-green mucus is joined by pains the patient can cover with a single fingertip.
The source
The remedy is prepared from potassium dichromate, an orange crystalline chromium salt used industrially in dyeing, tanning, and metal finishing. The crude salt is corrosive and a recognised occupational toxin; the homeopathic preparation is made by trituration and then potentisation through serial dilution and succussion in the standard Hahnemannian or Korsakovian methods. It was proved in the nineteenth century, notably by Drysdale, and expanded by Hering, Boericke, and Kent from their casebooks.
Across the tradition Kalium bichromicum occupies a recognisable niche centred on the mucous membranes: thick stringy catarrh of the nose and sinuses, certain stomach and ulcer states, and rheumatic pains that wander and localise to small spots. It sits alongside Hydrastis and Pulsatilla in catarrh work, separated from them by the quality of the discharge and the mental picture.
Keynotes
Two features are particularly distinctive: the ropy, thread-forming mucus, and the pain that fits under a fingertip. The features below recur across Boericke, Hering, and Kent with enough consistency to serve as a working checklist:
| Keynote dimension | What to look for |
|---|---|
| Discharge | Tough, ropy, stringy; can be drawn into long threads |
| Colour | Thick, sticky, yellow-green from nose and sinuses |
| Pain location | Small, well-defined spots a fingertip can cover |
| Pain behaviour | Wandering; shifts quickly from one place to another |
| Sinuses | Pressure and pain at the root of the nose |
| Modalities | Worse morning, cold, damp; better from heat |
Boericke captures the discharge concisely: "Secretions from all mucous membranes tough, stringy, adherent, can be drawn into long strings." The stringy mucus and the spot-sized pain are the two features that most reliably distinguish Kalium bichromicum among the catarrh remedies in repertory work.
Indications
- Thick, stringy sinus catarrh with pain or pressure at the root of the nose
- Postnasal drip with ropy, adherent mucus
- Later-stage cough with tenacious, difficult-to-raise sputum
- Rheumatic pains that wander rapidly and localise to small, well-defined spots
- Gastric ulcer states with ropy mucus and pain in a small spot, relieved by eating
- Headache in small spots, periodically recurring
Classical practice typically selects 6C or 30C, observing the discharge character across the episode and repeating on relapse.
Differential: Kalium bichromicum, Hydrastis, Pulsatilla
All three appear prominently in the thick-catarrh picture. The differential turns on the texture and colour of the discharge and the mental state:
| Dimension | Kalium bichromicum | Hydrastis | Pulsatilla |
|---|---|---|---|
| Discharge | Ropy, stringy, thread-forming | Thick, yellow, tenacious, raw | Thick, bland, yellow-green |
| Pain | Small fingertip-sized spots | Rawness, smarting | Wandering, with weepiness |
| Sinuses | Pressure at root of the nose | Postnasal, with sore throat | Worse in warm rooms |
| Mental marker | Few mental keynotes | Low, despondent | Tearful, wants company and open air |
For the milder potassium salt with a stronger chest and constitutional picture, see Kali carbonicum. For the bland-discharge weepy picture, see Pulsatilla nigricans.
Safety
Crude potassium dichromate is corrosive, a recognised skin and respiratory sensitiser, and a regulated occupational hazard. Never source or handle the crude salt; it is in no way interchangeable with the potentised preparation.
High or persistent fever, severe facial pain or swelling, periorbital redness or swelling, stiff neck, breathing difficulty, blood in the sputum, or a cough persisting beyond three weeks is a red-flag presentation needing prompt assessment.
Working with the repertory
Searching a plain-language phrase such as "stringy ropy nasal discharge" or "pain in small spots" in the free repertory surfaces the rubrics the classical tradition assigns to these presentations, placing Kalium bichromicum in context among the catarrh and sinus remedies.
References
Drysdale, J. J. (1846) Provings and clinical observations of Kali bichromicum, British Journal of Homoeopathy; reprinted in the nineteenth-century proving literature.
Boericke, W. (1927) Pocket Manual of Homoeopathic Materia Medica with Repertory, ninth edition, Philadelphia: Boericke & Tafel; entry on Kalium bichromicum.
Hering, C. (1879–1891) The Guiding Symptoms of our Materia Medica, ten volumes, Philadelphia: F. E. Boericke; Kalium bichromicum entry.
Kent, J. T. (1905) Lectures on Homoeopathic Materia Medica, Philadelphia: Boericke & Tafel; remarks on Kalium bichromicum, Hydrastis, and Pulsatilla.
U.S. National Library of Medicine (2024) Potassium dichromate: hazard and toxicology profile, PubChem / Hazardous Substances Data Bank.