This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
Dujardin Beaumetz has advocated the use of phosphorus in ataxia, upon the strength of four partially successful cases, of which, however, the after-history is not given. His favorable observations have not been generally confirmed, though a patient said to be suffering from "progressive locomotor ataxy," unrelieved by bromides, strychnia, quinine, and iron, was able to stand and to walk after two months' treatment by phosphuretted oil (Hartley: Lancet, i., 1877), and some other scattered observations may be found. The malady exhibits, in its natural course, remission and improvements, partial, and lasting for a variable time, but sufficient to throw uncertainty on the action of any medicine, unless very carefully and frequently verified. This was instanced in one of eighteen cases of ataxy reported by Mr. Bradley (British Medical Journal, ii., 1878); the improvement observed might have been credited to the remedy, had not the patient relapsed afterward while under the same treatment. The others remained in statu quo. It is possible that, in these and similar instances, the dose was too large, or not continued long enough, and further observations should be made. Certainly, in some few cases I have seen much improvement during a prolonged use of phosphorus (1/100 gr.) or zinc phosphide, though I am not satisfied that it was really due to the drug.