Unguentum Hydrargyri Ammoniati

Ointment of ammoniated mercury. Composition: Ammoniated mercury, l0 grm.; benzoinated lard, 90 grm.

Hydrargyri Iodidum Flavum

Yellow mercurous iodide. A greenish-yellow powder, which becomes red when heated. It is insoluble in water and alcohol. Dose, gr. 1/6—gr. j.

Hydrargyri Iodidum Rubrum

Red mercuric iodide. A red powder, which becomes yellow when heated, and red again when cold. It is wholly volatilized by heat, condensing in scales, which are at first yellow, but afterward become red. It is insoluble in water, but is dissolved by boiling alcohol, and by solutions of iodide of potassium and chloride of sodium. Dose, 1/30—gr. 1/10.

Unguentum Hydrargyri Iodidi Rubri

Ointment of red mercuric iodide. Composition: Red iodide, 5 parts; ointment, 95 parts.

Hydrargyri Sidphidum Rubrum

Red sulphuret of mercury. Cinnabar. In brilliant crystalline masses, of a deep-red color and fibrous texture. It is entirely volatilized by heat. When heated with potassa it yields globules of mercury. It is not soluble in either nitric or muriatic acid, but is dissolved by a mixture of the two. Acetic acid which has been digested with it does not yield a precipitate with iodide of potassium.

Liquor Hydrargyri Nitratis

Solution of mercuric nitrate. Mercury dissolved in nitric acid. Acid nitrate of mercury. "A transparent, nearly colorless, acid liquid, having the specific gravity 2·100. It is not precipitated by the addition of distilled water; and the diluted solution affords, with potassa, a dirty-yellow precipitate, and with iodide of potassium a bright-red one, soluble in an excess of the precipitant. When dropped on a bright surface of copper, the diluted solution instantly deposits a coating of mercury."

Unguentum Hydrargyri Nitratis

Ointment of mercuric nitrate. Citrine ointment.

Unguentum Hydrargyri Nitratis cum ol. Morhuae

Not official. In the preparation of this ointment there are two steps: Solution No. 1 is composed of cod-liver oil, 13 oz.; lard, 3 oz. Solution No. 2 is made by dissolving 1½ oz. of mercury in 3½ ozs. of nitric acid. By a heat of 200° Fahr., the lard is dissolved in the oil. Both solutions are slowly mixed by stirring until thoroughly incorporated.

Antagonists and Incompatibles

Corrosive sublimate is incompatible with alkalies and their carbonates, lime-water, tartar emetic, nitrate of silver, acetate of lead, albumen, iodide of potassium, soaps, various vegetable infusions, including cinchona. Calomel is incompatible with the alkalies and alkaline earths and alkaline carbonates, with iron, lead, and copper. It should not be given in the same prescription with iodine (forms red iodide), and nitro-muriatic acid should not be prescribed in conjunction with it, lest corrosive sublimate be formed. There is little doubt, also, that calomel is converted into corrosive sublimate by the chlorides of sodium, potassium, and ammonium. The acids and acidulous salts are incompatible with hydrargyrum cum creta.

In cases of poisoning by mercurial salts, especially corrosive sublimate, albumen, white of egg, wheaten flour, milk, etc., may be administered. The white of one egg is considered sufficient for four grains of corrosive sublimate. An excess of albumen may redissolve the compound. Emesis should be promptly induced.

Synergists

Depressing medicines, antimony, alkalies, especially alkaline chlorides, etc., promote the physiological activity of mercurials.

Physiological Actions of Mercury

Metallic mercury in direct contact with the skin or mucous membrane is without action. Swallowed, it is purgative by virtue of its weight. If retained in the intestinal canal, it will form soluble combinations, enter the blood, and produce characteristic systemic effects. Similarly prolonged contact with the skin will be followed by the constitutional action of the drug. Injected into the veins, it will be arrested in the capillaries, producing the usual phenomena of capillary embolism. Mercury gives off vapors at the ordinary temperatures, which have, in notable instances, caused serious constitutional symptoms. As used in the mechanical arts, by gilders and others, the fumes of mercury cause wasting, ptyalism, necrosis of bones, trembling, impaired intellect, and in women, abortion. Without producing such obvious effects as ptyalism, mercurial cachexia, eczema, and disease of the bones, obscure nervous phenomena may result. Among these may be enumerated headache, loss of memory, trembling, defects of co-ordination, disorders of sensation, convulsions, and dementia.

Mercury is readily absorbed as a vapor by the pulmonary mucous membrane, when applied to the integument, or when taken into the alimentary canal. It probably exists in the blood as an albuminate

Recent experiments (Wilbouchewitch, Keyes) have shown that mercury, as iron, manganese, and other metals, has the power to increase the number of red corpuscles, and to improve the quality of the blood, provided it is exhibited in small quantities, not often repeated. It has long been known (Liegeois) that this result followed the use of corrosive chloride in syphilis. Schlesinger has recently gone over the question anew with the same result, but he doubts whether the effects are really tonic. It remains true, however, that any considerable quantity of mercury, administered a sufficient time, will affect the quality and composition of the blood; the red globules are diminished in number; the fibrin loses its plasticity; the proportion of water is increased, and various effete materials, whose nature is unknown, accumulate. Mercury is deposited in all the textures, interferes with the normal nutritive processes, and is found in all the secretions and excretions. A marked degree of anaemia, loss of flesh, muscular weakness, intractable ulcerations of the skin, loss of hair, eczema, a foul breath, diarrhoea, the stools being very fetid, are the characteristic symptoms of the action of mercury on the solids and fluids of the body.

This metal has a selective action on the lymphatic glandular sys-.tem, and notably on the salivary glands and pancreas. Among the earlier symptoms of the action of mercury are an increase of the salivary secretion, an alteration of its quality, fetor of the breath, swollen tongue, soreness of the teeth, a blue or dark slate-colored line along the margin of the teeth, sponginess of the gums, swelling of the parotid, sublingual, and submaxillary glands, aching of the jaws and teeth, with general muscular soreness and aching of the limbs, and some elevation of temperature. To this state are applied the terms acute mercurialismus, ptyalism, in common language, salivation. Mercury certainly stimulates the pancreas; this gland, like the salivary glands, becomes swollen, congested, and pours out an abundant, secretion which, however, is not a normal but a pathological secretion. There is little doubt also that mercury increases the action of the intestinal glandular appendages, and thus acts as a purgative. It not. only increases the activity of these glands, but is itself in part excreted by them. The products of the increased waste of the tissues caused by mercury are also largely eliminated by the intestinal glands.

Although calomel had been long known to act well in some cases of dropsy, especially when associated with squill and other diuretics, the untoward effects not infrequently observed—since known to be examples of renal dropsy with albuminuria—lessened confidence in its utility, and increased the distrust felt of all mercurials, against which a general revolt was rising. The experimental method and the growth of a truer scientific spirit have combined to revive confidence in the use of mercury, and hence the former belief in its diuretic power has been subjected to clinical trials by such observers as Leyden [Therap, Monatshefte of April, 1887], Rosenheim and Fülrbringer [Ibid.], Wein-stein [Wiener med. Blatte, 1887], and Jendrassik [Deutsch. Archiv f. klin. Med., April, 1886], with many others.

These recent experiences confirm the belief in the diuretic action of calomel, formerly an article of medical faith. The quantity required to act on the kidneys, and the conditions under which this physiological property is manifested, have been the subject of careful inquiry, and conclusions of a practical character have been reached. It is generally held by those most familiar with its diuretic action that the dose of three grains three times a day is about the quantity usually required. Experience has shown that more than this will cause diarrhoea or more serious trouble of the gastro-intestinal mucous membrane, and the danger of acute mercurialismus rises with the quantity administered.

Although the diuretic property is an endowment of calomel per se, and is exerted under suitable conditions, it is quite certain that in the renal dropsies there is far more danger of ptyalism, and the explanation of this is afforded by the changes in the composition of the blood due to albuminuria. To prevent ptyalism, the use of potassium chlorate is practiced from the outset, and diarrhoea is prevented or restrained by the conjoint administration of opium. Such are the prophylactic measures suggested by some of those advocating the diuretic property of calomel, and who are mentioned above. Although anticipating somewhat, the author has to say that the combination of belladonna extract with the calomel has an excellent effect both to prevent diarrhoea and ptyalism, and is more efficient in the latter, and is active enough, usually, to keep the former in due restraint.

An explanation of the diuretic action of calomel may be sought for in several directions. It is well known that purgatives often increase renal action by an influence reflex in mechanism. From the intestinal mucous membrane an impression is radiated by means of the solar plexus over the nerves of the renal system. If, however, the blood pressure is reduced by profuse watery evacuations, the kidneys do not act as strongly. It would seem, on first view, that the compound jalap powder acts in a manner opposed to the explanation just given, for it produces watery evacuations and also diuresis, but the renal action is a consequence of the bitartrate.

The misconception of the action of mercurials on the liver has prevailed chiefly because of the peculiar evacuations produced by it. The true explanation of the nature of these stools has been given above, but the subject should not be dismissed without further reference to the experimental work devoted to the elucidation of this subject within the past few years. The experiments of Röhrig, Rutherford, and Scott on animals, and the observations of Westphalen and Ranke in cases of biliary fistulae in man, have thrown a flood of light on the actions of mercurials, and there seems to be no longer any reason to doubt the accuracy of the conclusions reached. It has been shown that calomel lessens the physiological activity of the liver, and consequently diminishes the production of bile. Instead of stimulating the liver, or acting as a cholagogue, calomel must be regarded as a sedative, and as having the power to allay an irritable state of the liver. Oddly enough, this fact harmonizes in the most satisfactory way with clinical experience, for calomel has always been regarded as useful in the highest degree in those cases of "biliousness," characterized by a surplusage of bile, due to an over-acting liver. Under such circumstances an active cholagogue, stimulating the productive capacity of the organ, would only increase the existing complications.

While the sedative action of mercurials, including calomel and its congeners, on the hepatic functions has been established, by the same kind of investigation it has demonstrated that the corrosive chloride is to some extent a cholagogue increasing the production of bile (Rutherford), and as its stimulating action must include the glycogenic function as well, it may be supposed that its tonic and reconstituent power is thus produced. If we add to the cholagogue properties of mercury, which it possesses in common with resinous purgatives, the action on the pancreas and the increased elimination of the products of waste by the intestinal glands, we obtain a satisfactory explanation of those powers which have, under the term alterative, been heretofore ascribed to mercury.

Mercury is eliminated by the salivary and the intestinal glands, by the liver, but chiefly by the kidneys. As a result of the changes in the composition of the blood, and of the direct action of the metal on the renal epithelium, albuminuria is one of the symptoms present in cases of mercurialism. Without the use of special means to render it soluble, and despite the use of such means, sometimes mercury remains permanently in the organism. When extremely severe cases of salivation were not uncommon, permanent damage to the osseous structures often occurred, and globules of mercury could be shaken out of the dried bones of such subjects. Happily, nowadays, such cases do not occur. The moderate use of mercury, short of ptyalism, does not appear to affect the human system injuriously.

There are but few chronic affections of the nervous system not imitated in the multiform examples of chronic mercurialism. From the most trifling affections of sensibility and motility up to complete anaesthesia and paralysis, there are numerous gradations in the importance of the lesions. From slight headache and impaired memory up to complete dementia there are, also, immense variations in the gravity of the mental and cerebral symptoms. The most frequently encountered nervous lesion is "trembling," and to this symptom more attention has been given, from the period of Küssmaul's elaborate essay, up to the present.

It has been supposed hitherto, that the mercurial trembling is ac companied by muscular paresis, but recent observations have shown that this view of their absolute association is incorrect, the two conditions not necessarily being present together (Letulle). The paresis, which is usually more pronounced in the upper extremities, is not attended by trophic changes, as a consequence—the muscles flaccid, but not degenerating. At the beginning of the structural changes the reflexes are rather heightened, but, as the paresis increases, they decline. The electrical reactions are normal in character, but a quantitative decline sometimes occurs. Disorders of sensibility accompany the motor derangements. A characteristic of the disordered sensibility is its localization to defined areas, the whole member not being affected, and the restriction to the extremities, the trunk remaining unaffected. The actual disorders of sensibility consist in lessening the tactile and pain sense, and in an aberration of the sense of temperature; but rarely is there a complete abolition of the sensibility, and usually the changes are rather of a fugitive character. Corresponding disorders of function appear in the organs of special sense, and are due to atrophic degeneration of the nerve-elements. Huskiness of voice, even complete aphonia, have been the result of paralysis of the laryngeal muscles.

From the point of view of pathology, the motorial and sensory disturbances caused by mercury are due to a direct action on the protoplasm of a destructive character, and in respect to the nerve-elements (Hallopeau) the initial changes occur in the most highly specialized. Like arsenic, lead, and other metals, mercury sets up a fatty degeneration of the gland-cells.