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.
From the time that Robert Hamilton described his successful treatment of inflammation by calomel and opium ("Duncan's Commentaries," 1764) down to perhaps twenty or thirty years ago, mercury in some form was, in English practice at least, the almost universal remedy both for acute inflammations, and for their results, such as effusions, adhesions, and indurations. Trousseau described mercurials as "les antiphlogistiques les plus puissants" - more active, perhaps, than blood-letting - and Nothnagel remarks that at one time the name of any malady ending in "itis" seemed sufficient to indicate their use. Sir Thomas Watson, in the later editions of his classic lectures, quotes his own earlier opinion that "mercury is a very powerful agent in controlling inflammation, especially when acute and ' adhesive ' in character, also in preventing exudation," but owns that this can be said no longer - "it requires much qualification" (5th Ed., 1871). This is perhaps the most important point in which modern experience and opinion would discredit the therapeutical power of mercury. It is not denied that full doses can act destructively on the blood and the tissues, though we have given some evidence against its aplastic energy (v. p. 194), but modern clinical experience affirms that it has not great, but comparatively little power over acute inflammatory disorders, that these often run a natural course toward recovery independent of mercurial, or other medicinal treatment, and that when it is pressed to a full effect convalescence is protracted by greater anaemia and debility. (The unquestioned good results recorded from the treatment of Hamilton, which led to its general adoption, have been plausibly attributed to the opium rather than to the mercury.) Sufficient account of the evils that followed was not made by our predecessors, who, knowing too little of the natural history of disease, attrib-uted all bad sequelae to it rather than to the medicines, and considered themselves successful if, when "the disease was subdued," life at least was saved.
We cannot, on the other hand, agree with the assertion that mercury is never useful but always injurious in inflammation. There is evidence of its advantage in certain conditions, though this evidence is not so con-sistent nor so general as of its value in syphilis. It will certainly remedy some of the results of inflammation, as chronic effusions in joints or lungs, and, as Dr. Stephenson remarks when narrating such cases, no number of instances in which the medicine has been abused, or even has failed, can contradict the cases in which it has conferred evident benefit (Edinburgh Medical Journal, 1871). Dr. Habershon allows its value in cases of retained secretion, dropsy, gastric disorder, as a purgative, and as anti-syphilitic, but objects to its use in all degenerations and passive congestions, in fevers and exhausted conditions, in diseases of mucous membrane, in rheumatism, and all inflammations of lung, brain, etc. (Pamphlet on Mercury, British and Foreign Review, ii., 1860). For my own part, I still hold it useful in many chronic inflammations, whether syphilitic or not, affecting mucous and parenchymatous tissues, and having a general tendency to suppuration and ulceration, but I am satisfied that it should never be pushed to salivation.