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.
The hypothesis of ague being dependent upon the absorption of minute fungi or spores given off by the soil of malarious districts has been forcibly maintained by H. Schmidt, Salisbury, and others, who have even reported the finding of such microscopic organisms in the blood and secretions of patients, and in the neighboring marshes (Lancet, ii., 1867, p. 588). Evidence in favor of this theory seems furnished by such instances as that of the ship Argo, which took on board for (water supply to) a band of soldiers, water from a malarious district, and almost all who drank of it got intermittent fever, while the sailors of the same vessel, who had a different water supply, did not suffer (Lancet, loc. cit). Still, the hypothesis is not proved, and clinical evidence as to the value of sulphite treatment is contradictory - thus, while Sanger refers to four cases of intractable ague, soon relieved and ultimately cured by scruple doses of hyposulphite of soda (Lancet, i., 1869), McClean criticises the result, and notes that quinine and other remedies had been previously used, and that it it is well-known quinine often does not cure, unless a blood depurant, such as potash or soda first be given, and moreover many cases in the Mauritius were treated by the sulphites without effect, and were afterward cured by quinine (Lancet, i., 1869, p. 511). Several American writers have reported the cure of intermittents by hyposulphites after failure of quinine (Ranking, Abstract, ii., 1868, ii., 1870), but Farelli, from an exhaustive analysis of the recorded evidence, concludes that their good effect is neither so quick nor so constant as that of the latter; they are not prophylactic, and their continued use leads to anaemia: he holds that their action, such as it is, "is reductive, not disinfectant" (Abstract, Lancet, i., 1873, p. 634).