A form of periostitis occurs sometimes during a course of mercury, and it has been a question whether this is due to the remedy or to the malady (syphilis), for which it is commonly prescribed. Pereira thinks the latter supposition correct, but Graves states that he has seen periostitis occur in patients mercurialized for some other illness, and who had never contracted syphilis, and to this I can add my own testimony, having witnessed such an occurrence several times. The tibia, the bones of the forearm, the clavicle, sternum, and frontal bones are those more commonly affected, and the pains, intermittent at first, are increased by warmth, or by changes of temperature, though sometimes relieved by a low temperature. The articular ends of the bones are liable to be affected, and even caries may be produced.

Synergists

Agents which fluidify the blood and secretions, such as alkalies, favor a similar action in mercury. Oxygen, dilute acids, and alkaline chlorides favor the transformation and absorption of metallic mercury, and hence assist its action. Bellini, however, concluded that these agents lessened the effect of mercurial chlorides and iodides by preventing the action of carbonated alkalies upon those salts in the intestine, and impairing the formation of double salts: magnesia he found distinctly adjuvant, it giving rise to a double chloride with mercury. Carbonate of soda has been found to increase its purgative effect (Hunt: British and Foreign Review, ii., 1852), and rhubarb, colocynth, jalap, or other purgatives are used to aid its action on the liver or intestine.

Alkaline iodides markedly increase the constitutional action of mercury - Wreden has especially shown this (Central Zeitung, 99, 1874, and British Medical Journal). A skin rubbed with blue ointment, and then after an interval, and after cleansing, rubbed with iodine ointment, becomes much inflamed, evidently from a chemical combination (biniodide of mercury). Milk, bromides, sulphites, and prussic acid, are also said to increase the effect of mercurial compounds (Bellini), and the good effects of mercurial treatment in syphilis are specially aided by the concurrent use of the sulphurous waters of Aix-la-Chapelle (British Medical Journal, i., 1874, p. 108).

Antagonists And Incompatibles

Sulphur, especially in the form of sulphuretted hydrogen, antagonizes the physiological action of mercurial compounds, whatever their therapeutical relations may be (see above). Chlorate of potash controls, to some extent, its salivating powers; astringents, such as alum and tannin, lessen fluxes, and tonics and stimulants oppose mercurial cachexia.

Finely divided iron, or zinc, or gold, acts as a mechanical antidote in cases of mercurial poisoning (Johnston: American Journal, April, 1863), but albumen is, perhaps, more efficient: the white of one egg is calculated to form an insoluble compound with 25 centigrammes (about 3 1/2 gr.) of sublimate (Peschier).