Mercury

MERCURY, Hydrargyrum (from Greek hydor - water and argyros - silver), Mercurium, Hydrargyrum vivum, s. metallicum, Mercurius vivus, Argentum vivum, a silver-white liquid metal, symbol Hg, atomic weight 200.61; specific gravity 13.573; atomic volume 15.4; freezing point -38.87°; boiling point 357° (yielding colorless, odorless, and tasteless vapors); heat capacity 6.0329; occupies the 80th position in the periodic system of elements in the 11th row of the 2nd group; evaporates even at normal temperature, vapor pressure at 15° is 0.0008 mm, and at 100° is 0.28 mm. It is found in nature in compounds and in native form: compounds are mainly sulfur-based - cinnabar, from which mercury is mined in Austria, Испании [Spain], Yugoslavia, California, Peru, Mexico, Borneo, China, Japan, USSR (Urals, Donbass - Nikitovka; cinnabar deposits were recently discovered in Turkmenistan, in the Kopet-Dag mountains, in Fergana, and in the Nerchinsk district); it is often encountered in the form of droplets in rocks; the most important ore of mercury is cinnabar. Mercury and its extraction from ore was known long before our era: Aristotle and Theophrastus (300–350 BC) mention mercury. The name Hydrargyrum is first found in Pliny (23–79 AD). Alchemists gave mercury the name "Mercury" (Mercurius vivus) due to the ease of movement of a drop of mercury. The use of mercury for the treatment of skin diseases was adopted from Arabic medicine, and from the 16th century (Paracelsus - around 1530) mercury began to be used in the therapy of syphilis. Metallic mercury is extracted from cinnabar ore. Cinnabar (HgS) exists in 2 modifications - in the form of a black amorphous mass and dark red needles. Cinnabar is insoluble in water, nitric acid, or body juices and is therefore non-toxic, barring the possibility of the formation of mercury vapors; it is soluble only in aqua regia. In water with access to air, only traces of mercury dissolve; mercury is more soluble in a sodium chloride solution with the formation of double salts of corrosive sublimate and sodium chloride. It is readily soluble in hot concentrated sulfuric acid, nitric acid, and aqua regia. It does not react with hydrochloric acid, cold concentrated sulfuric acid; with chlorine, bromine, and iodine it forms halide compounds, and it combines with sulfur. With most metals (except iron and platinum) mercury forms alloys - amalgams (see), from which it volatilizes upon heating. It reacts well with hydrogen sulfide and hydrogen iodide. By trituration with chalk, gums, fats, and oils, it can be broken down into the smallest droplets. It reacts very sluggishly with oxygen; only at temperatures close to the boiling point does it form red oxide. Compounds of mercury. Mercury forms two kinds of compounds: mercuric, oxide, divalent salts (e.g., HgCl₂), having the mercury cation Hg" in aqueous solution, and mercurous, suboxide, monovalent salts (e.g., Hg₂Cl₂), having the mercurous cation Hg*. Suboxide Hg₂O and oxide HgO have a weakly expressed basic character. The suboxide is formed as a black-brown precipitate upon the addition of bases to a solution of its salts; under the influence of light or moderate heating, Hg₂O decomposes into mercury oxide and metallic mercury. Mercury oxide is known in 2 forms - crystalline red and amorphous yellow; the former is the smallest, yellow-red powder, insoluble in water, soluble in weak hydrochloric or nitric acids; yellow oxide is a heavy, very fine powder, insoluble in water, easily soluble in hydrochloric and nitric acids. Mercury salts are volatile; when heated with soda in a test tube, a metal coating is obtained. Suboxide salts are formed with an excess of mercury, and oxide salts with an excess of an oxidizing acid or other substances. Reducing agents convert oxide salts into suboxide salts, and oxidizing agents produce the reverse effect. The classification of mercury preparations can be chemical: 1) inorganic compounds - containing metallic mercury, oxide and suboxide salts, and 2) organic compounds. Regarding pharmacological action, a division according to solubility and the degree of dissociation is important, since the speed of absorption and action depends on these properties; out of a large number of mercury compounds, very few are soluble in water (mercuric chloride, cyanide, oxycyanide, partly mercuric nitrate), but insoluble preparations can find conditions for dissolution in the organism. Action on the organism. Mercury is a strong protoplasmic poison, the toxicity of which depends on specific Hg-ions and is therefore inherent mainly to soluble and dissociating salts, e.g., corrosive sublimate. There is some difference in the local action of various preparations, but the general action is the same; according to Heubner, the effectiveness of mercury salts is related not only to metal ions, but also to the action of complex compounds formed during the reaction of these salts with polypeptides. The toxicity of mercury is manifested in single-celled and multicellular organisms; the latter is clearly visible on the skin and mucous membranes upon a single application of soluble or prolonged exposure to insoluble compounds. Even metallic mercury when rubbed into the skin in a finely divided state can lead to inflammation, and when injected into tissue it produces pain, swelling, and abscess; strong solutions of salts can produce dry tissue necrosis. Small doses of mercury, exerting a clear effect in syphilis, usually do not cause any noticeable general phenomena in healthy individuals. The only thing that had to be observed with the prolonged administration of very small quantities of mercury is some intensification of diuresis, an increase in the number of erythrocytes, and an increase in body weight; the former is attributed to the irritating effect of mercury on the excretion pathways, and in the case of calomel, in addition, to an extrarenal factor - a decrease in the affinity of tissue colloids for water and the resulting hydremia, which also depends on the absorption of water retained in the small intestine (see Calomel); the diuretic action is strongest when water is retained in the organism; the second phenomenon depends on the stimulation of hematopoiesis; the action on metabolism, according to some authors, is associated with a decrease in oxidative processes, leading to fat deposition; according to other authors, mercury promotes the latter phenomenon similar to phosphorus and arsenic. Clinical observations have confirmed the beneficial effect of small doses of mercury in cachectic children: an acceleration of growth, weight gain, an increase in the number of erythrocytes, hemoglobin, polynuclears, and an increase in nitrogen metabolism are detected. Regarding the laxative action, see Calomel. To study the resorptive action of mercury, researchers usually resort to the intravenous administration of soluble preparations to animals. The effect occurs after sufficiently massive doses. A drop in blood pressure associated with weakened the heart and vasodilation, frequent, irregular, intermittent respiration, gastrointestinal disorders in the form of diarrhea, sometimes with blood, pain and tenesmus, sometimes vomiting and salivation, body tremor, increased psychic excitability, and asphyctic convulsions are noted. Death occurs from cardiac paralysis (damage to the muscle and ganglia) and the respiratory center. At autopsy: inflammation, in places hemorrhagic ulcers of a necrotic, diphtheritic, or dysenteric character, mainly in the region of the large intestines; in the kidneys: parenchymatous nephritis, degeneration of the tubular epithelium, formation of epithelial and hyaline casts, sometimes hemorrhages, deposits of calcium phosphate and calcium acetate in the epithelium and in the lumen of the tubules up to their complete blockage; in the blood vessels: degeneration of the walls and accumulation of erythrocytes in the capillaries; a decrease in blood alkalinity, a lower calcium content in the bones, their brittleness; in parenchymatous organs, degenerative phenomena with a tendency to coagulative necrosis, particularly in the liver. Heart and vascular lesions have also been confirmed in experiments on isolated organs. Complex and semi-complex compounds of mercury differ in their action from ordinary mercury compounds: initially they manifest their specific influence, while the action of the metal occurs later when their decomposition begins; upon the administration of non-lethal doses, the first phase is manifested by central phenomena, followed by the usual picture of mercury poisoning; in acute intoxication, the picture is similar to the picture of acute poisoning by other preparations. In chronic poisoning from organic mercury compounds, organic chloride salts are formed, and then mercury is split off from the organic residue. Colloidal mercury compounds, which are colloidal solutions of the metal, exhibit pharmacological action depending on the presence of free ions; in view of the small number of the latter, with the indifference of the bulk of the metal, the indicated action is relatively weak, and such compounds can be in contact with tissues for a long time. Habituation to mercury is insignificant. There are cases of idiosyncrasy: for example, cases of poisoning have been described after brief immersion of fingers in a 0.05% solution of corrosive sublimate and after washing hands with a 1% solution of it. Action on microorganisms. Being a protoplasmic poison, mercury acts lethally on microorganisms, a property which is to a greater extent inherent in soluble and dissociating compounds, e.g., corrosive sublimate, than in insoluble ones. Most microbes perish or lose the ability to multiply in a solution of corrosive sublimate; spores are more resistant.

Minimal doses of mercuric chloride have a stimulating effect on microorganisms; a 1 : 6 million solution of it enhances the activity of yeast. The disinfecting effect of mercury, as some authors suggest, is based on 2 phases—adsorption on the surface of bacteria and penetration inside the cells; according to other authors, this action is associated with the coagulation of microbial protein. The bactericidal action of mercury is determined by the number of free ions present in the solution, which is why it is stronger in mercuric chloride and weaker in mercuric cyanide. Sodium chloride, by lowering the dissociation of the mercuric chloride solution, weakens its disinfecting effect. But besides this fact, solubility in the cell lipoids is of importance, which is once again more pronounced in mercuric chloride. The activity of the action under discussion is reduced by the presence of organic material on the tissue surface, by the presence of hydrogen sulfide and ammonia, since a part of mercury is precipitated by these substances. In small doses, mercury compounds possess an antiseptic action, also associated with the presence of free Hg-ions; insoluble salts are more suitable for this purpose as being less irritating and remaining in more prolonged contact with wounds or mucous membranes in comparison with soluble compounds. A certain amount of free ions in colloidal preparations of mercury allows their antiseptic use for a long period in view of the absence of an irritating effect; due to the binding of the greater part of the metal in such compounds in an indifferent state, they are not suitable for a disinfecting action, which does not manifest itself even in large concentrations. The therapeutic effect of mercury in syphilis partly depends on the specific etiotropic effect on the causative agent and manifests itself slowly from very high dilutions of mercury (in vitro, mercuric chloride kills spirochetes at a dose of 1 : 200 thousand); apparently, mercury possesses an affinity for spirochetes greater than for tissues or other microorganisms, for example, malaria plasmodia, trypanosomes. The local action of mercury is associated with the formation of an adsorption compound with the protein of tissues and tissue juices (albuminate) and with the specific action of metal ions. According to the degree of action, astringent, irritating, and caustic effects are distinguished. During the formation of albuminate in local action, a role is played by the acid released from the mercury salt, the degree of dissociation of the acid itself and of the mercury preparation itself (organic compounds act weaker than inorganic ones), the nature of the albuminate itself, its solubility in water, juices, sodium chloride, in an excess of protein or precipitant, the repetition of exposure, the concentration of the applied solution, the affinity of the compound for water; all these indicated factors can alter the toxicity of the mercury salt. For the purpose of local action, soluble preparations associated with an inorganic acid radical are more often used, for example, mercuric chloride and mercuric nitrate, exhibiting an irritating or caustic effect; organic mercury salts possess the least irritating and caustic effect, but with some exceptions due to the toxicity of the ions themselves, e.g., in the case of the acetate salt; less soluble or completely insoluble compounds or very small concentrations of soluble salts have an astringent effect, but with prolonged exposure to them, tissue irritation may occur. In general, mercury salts in comparison with identical salts of other heavy metals possess a stronger local action (Schmiedeberg). The action of soluble compounds is inherent in mercury albuminates. The absorption of mercury occurs by all routes quite energetically, even when rubbed into the intact epidermis. A number of factors contribute to absorption, among which the dissolution of mercury compounds in sodium chloride is of important significance, facilitating their conversion into complex protein compounds. In the skin upon rubbing in ointments, mercury is found in the form of a finely divided metal, protein compounds, compounds with fatty acids, and also in the form of oxide and suboxide compounds; the cutaneous depots of mercury are the openings and ducts of sweat glands, hair follicles, and sebaceous glands. Soluble and insoluble salts are usually administered per os, more rarely metallic mercury; the former are absorbed quickly, the second and third slowly; absorption proceeds in the form of albuminates (oxychloralbuminates). The subcutaneous method is rarely used because of pain upon injection of soluble preparations and the almost complete non-absorbability of insoluble salts. Insoluble compounds are used for intramuscular injections; their absorption is comparatively rapid, but unequal with various preparations; a known role in this is played by the vehiculum; thus, for example, liquid paraffin is absorbed very slowly and thereby slows down the absorption of mercury, while olive oil and lanolin are resorbed quickly. It is believed that upon intramuscular injections, mercury is absorbed in the form of protein compounds (mercury albuminates). Upon the inhalation of mercury vapors, the latter are absorbed not by the lungs, but only by the mucous membranes of the upper respiratory tract, if these vapors are heated to a temperature above body temperature; at a temperature of the inhaled air equal to body temperature or below it, the vapors are absorbed by the lungs. The method of this adsorption is unknown; it is assumed that mercury is deposited in the form of metal and its oxides, or the vapors dissolve in the liquid of the moist surface and thus enter the blood in the form of albuminates. The rate of passage of mercury from the air into the blood depends on the ratio of the concentration in the air and the indicated liquid, and this in turn is connected with the air temperature, the surface of contact of the vapors with the air, the rate of exchange of the latter in the room, and in the case of metallic mercury, also with the degree of its division. The adsorption of vapors by the lungs proceeds quickly and completely. The adsorbed mercury remains in the alveolar epithelium for some time, a part of it is exhaled back. Distribution of mercury in the organism. From the sites of administration and from local depots, mercury enters the blood, which is 10 times more receptive to it than water; in the blood, it is concentrated chiefly in the plasma. The greater part of the absorbed mercury upon any method of administration accumulates predominantly in the kidneys (the presence of mercury in the tubular epithelium is histologically proven), so that its concentration in the urine can be greater than in the blood; upon the excretion of mercury in the urine in an amount greater than 10 mg, damage to the parenchyma occurs; in the remaining organs, the accumulation of mercury is less (in sequentially decreasing order): liver, intestinal walls (chiefly large intestine), lungs, spleen, pancreas, gall bladder, heart, brain, bone marrow, seminal glands; mercury is found in these organs in combination with globulins. According to Lomholt, in a patient who died during mercury treatment, there was found in milligrams per 100 g of tissue: in the kidneys—17, in the liver—3, in the spleen—1, in the remaining organs—less than 0.4. The mercury content in them is connected with the amount of it in the blood; upon severe inflammatory hemorrhagic phenomena in the intestine during mercury poisoning, more mercury can be found in it than in the kidneys. The most prolonged retention of mercury occurs in the kidneys, liver, and bones. The excretion of mercury by the kidneys serves as a measure of the saturation of the organism with mercury. During mercury treatment, the indicators of saturation are the uniformity of excretion during the treatment period and the gradual drop in the curve of this excretion after the cessation of treatment. The excretion of mercury proceeds chiefly with urine and feces; saliva, sweat, bile, gastric and intestinal juices, milk, and exhaled water have secondary importance. Excretion proceeds slowly and irregularly, which causes the cumulation of mercury; during mercury treatment, the daily content of mercury in the urine gradually increases and then slowly decreases; upon the cessation of treatment, it is detected in the urine for several months, and sometimes years. In individual portions of urine, despite a large accumulation of mercury in the organism, there may be very little of it, and for some time it may be completely absent, and then excretion begins anew. In the urine, it is detected in the form of salts and organic compounds. Excretion through the intestine proceeds irregularly and predominantly through the cecum and colon; according to some authors, mercury can be excreted by the entire gastrointestinal tract, including the salivary glands, liver, stomach, and intestine, but the site of excretion varies in different subjects; there is an assumption that the mercury that entered the intestine from the blood can be reabsorbed here, which accounts for the variability of its excretion with feces. In general, its amount in the latter does not exceed 25% of the total excretion; the maximum excretion per day is no more than 2 mg; at the beginning of mercury treatment, the feces contain less of it than urine, then the ratios change. Among many factors influencing the excretion of mercury by one or another pathway, the type of preparation, the method of its administration, and the amount of mercury in local and internal depots are of important significance. The daily amount of excreted mercury during treatment by rubbings reaches several milligrams; starting 24 hours after application, the main part is excreted with feces, the rest with urine. After intramuscular injections with the formation of a depot of poorly soluble compounds, usual therapeutic doses are resorbed within 1 week; after prolonged treatment in this way, months (3–4) pass before the organism is freed from mercury.

After a single intramuscular injection, 25-50% of mercury is excreted within 40 days: ³/₄ through the urine and ¹/₄ through the feces; the slowness of excretion is associated not only with the accumulation of mercury at the injection site, but also with its accumulation in the organism. The uneven excretion observed with this method of administration depends, among other things, on a larger amount of mercury suddenly entering from the depot. After intravenous administration, the excretion of mercury proceeds faster than with other methods, and is approximately equal through urine and feces; it appears in the urine 1 hour after injection; according to Buchtala, after the intravenous administration of 0.02 g of mercury tyrosinate, the following amounts were excreted in the urine: in the first 12 hours - 8%, by 24 hours - 18%, by 36 hours - 20%, by 48 hours - 28%, and by 60 hours - 30%. Mercury enters the fetus with the blood; it has been found in the placenta, which serves as a barrier to mercury, and in the amniotic fluid. Toxic and lethal doses of mercury are subject to variations depending on individual human characteristics, concomitant conditions, and the preparation used. Metallic mercury, with normal intestinal patency, is not poisonous even in large doses, because it does not find conditions for dissolution and absorption. Mercury vapors can cause poisoning and death; thus, the vapor from the evaporation of 2.5 g of mercury on a red-hot iron sheet causes fatal poisoning; traces of vapors upon prolonged inhalation lead to chronic poisoning. Mercuric (oxide) compounds are more toxic than mercurous. Thus, the toxic dose of corrosive sublimate is 0.1-0.2 g when taken by mouth, the lethal dose is 0.5 g; for children, the latter is 0.18 g; when administered intravenously, a fatal outcome results from 0.12-0.16 g of sublimate; the mercurous compound, calomel, can cause fatal poisoning after the oral administration of 2.0-3.0 g. Approaching sublimate in toxicity are cyanic and iodic mercury; for oxycyanic, nitric, bromic, and amidochlorine mercury, the doses are 2 times larger; organic compounds are approximately 3 times weaker than sublimate, with the exception of methyl and ethyl mercury, the toxicity of which equals that of sublimate. Poisoning by mercury can be acute, subacute, and chronic, and is related mainly to the form of administration of mercury, its quantity, and the ratio between absorption and excretion. They also differ from each other in the intensity of action and the character of the phenomena. The individuality of the subject also plays a major role. Ionized compounds more often cause acute poisoning, while atomistic ones (vapors or finely divided metallic mercury) cause chronic poisoning. Acute poisoning is observed after the absorption of large amounts of mercury into the blood in a short time and often ends fatally, especially after the intentional or careless intake of soluble preparations, e.g., corrosive sublimate. Typical poisoning occurs after intake by mouth. Complaints appear of a metallic taste and burning pain in the mouth, throat, and stomach; burns of the corners of the mouth and swelling of the lips. After a few days, less often hours, these are joined by abdominal pain, nausea, and vomiting; the vomitus contains fragments of mucosa and blood. Incessant diarrhea with severe pain, initially watery, then bloody, sometimes with pieces of mucous membranes. Such a lesion of the gastrointestinal tract is accompanied by collapse with a small, thready pulse, shallow, accelerated, and irregular respiration; temperature drops below normal, sometimes fever. Consciousness is preserved, there is drowsiness, dizziness, rarely a restless state; jaundice has been described. Simultaneously with the lesion of the gastrointestinal tract, diuresis decreases; after 2-3 days, protein, blood cells, bile pigments, renal epithelium, sediments, and less often sugar and waxy casts appear in the urine. Edema is sometimes observed. Then complete anuria and uremia follow; in severe cases, at this stage, transmineralization takes place, with the retention of nitrogen and chlorides in the organism and their depletion in the urine (low specific gravity). The prognosis of renal phenomena depends on the degree of oliguria. Often, after recovery, protein is excreted in the urine for a long time. Death may occur from shock within the first few hours, but more often the poisoning lasts several days (5-11) and even weeks (1-4); with progressive symptoms of intestinal and renal irritation, the patient dies from exhaustion and heart failure or from the consequences of kidney damage. In protracted cases, salivation and stomatitis may be observed, which are transitional moments to subacute poisoning. Upon inhalation of dimethyl and diethyl mercury vapors, along with the described phenomena, nervous symptoms may occur. The consequences of acute poisoning include scar strictures in the gastrointestinal tract, its disorders, skin rashes, and chronic nephritis. Lesions of the mucous membrane of the digestive tract are explained by the local caustic or irritating action of mercury preparations, as well as by the same action during the excretion of mercury from the organism; the latter is of primary importance in parenteral poisoning. Changes in the cecum, colon, and lower parts of the small intestine are promoted by the presence of a rich microflora. Renal phenomena depend on the irritating action of the excreted mercury. Changes in respiration and pulse are associated with shock and collapse. Pathological and anatomical picture. At the sites of absorption (in the corners of the mouth, in the mouth itself, on the mucosa of the tongue and cheeks, in the pharynx, rectum, uterus, vagina), there are grayish-white scabs passing into tumors, inflammation, ulcers, and gangrene. In the large intestines, and to a lesser extent in other parts, there is hyperemia, swelling, necrotic ulcers, sometimes of a perforative character, with punctate hemorrhages (dysenteria mercurialis); in the upper parts of the small intestines, inflammatory phenomena. In the kidneys, the picture of nephrosis (necronephrosis) — inflammation and necrosis of the glomeruli and tubular epithelium, with deposits of calcium phosphate and necrotic cells in the tubules. In the heart, fatty degeneration areas are found in severe cases, along with engorgement of the right heart; the blood is thick, dark, loosely coagulated; sometimes areas of degeneration are found in the liver and other organs, particularly in the pituitary gland and adrenal glands. Corpses of the deceased decompose slowly, rigor mortis is marked, and cadaveric spots are sparse. Treatment of acute poisoning. Gastric lavage using a tube is recommended if it can be introduced shortly after taking the preparation. To precipitate metallic mercury and protect the mucous membrane of the gastrointestinal tract, tannin, eggs, chalk, albumin water, and other protein substances are given; animal charcoal is suitable for the adsorption of mercury. Among laxatives, castor oil (Ol. Ricini) and magnesium sulfate (Magn. sulf.) are recommended. Apomorphine or irritation of the throat to induce vomiting is indicated. For disinfection of the intestine, high enemas of potassium permanganate (KMnO₄). To reduce kidney irritation and in case of anuria, abundant drinking, drip enemas with potassium acetate (Kal. acet.), sweating, atophan. It is recommended to give bismuth carbonate (Bismut. carbon.) and bismuth subnitrate (Bismut. subnitr.) aa 0.75 g 4–6 times a day per os as an astringent for the intestine, and glucose intravenously. To convert mercury compounds into sulfur-containing, low-toxicity salts, strontium thiacetate is given per os for 14 days at 1.0 g per day. Narcotics are indicated. Diet: salt-free (chloride-free). Subacute poisoning occurs more often as a result of the therapeutic use of mercury and depends on its accumulation in the organism when excretion does not correspond to absorption. Previously, a frequent cause of this form of poisoning was the use of soluble salts, and mainly corrosive sublimate, in the form of uterine and vaginal douches, as tablets inserted into the vagina, as lotions on extensive wound surfaces, sometimes among disinfectants, etc. Now these moments have lost their significance due to the adoption of precautions, although the use of sublimate per vaginam as a disinfectant, contraceptive, and abortifacient is still practiced occasionally. Cases of subacute poisoning by mercury are encountered as a result of quack use of mercuric nitrate or solutions of metallic mercury in nitric acid diluted with water, or a mixture of mercurous and mercuric nitrates with mercury fulminate for the treatment of syphilis; there are indications of such cases after the use by quacks of cottage cheese with sublimate as a cosmetic for freckles, after the application of various creams by beauty institutes (amidochlorine mercury). Next in frequency of caused subacute poisoning are insoluble and soluble mercury compounds for intramuscular injections; among new preparations, novasurol and salyrgan frequently cause poisoning. A more rare cause is the rubbing of mercurial ointments in the treatment of skin diseases and syphilis, and the inhalation of mercury vapors in industries. Poisoning by rhodanic mercury in children playing with so-called Pharaoh's serpents is very rare. Subacute poisonings also occur as a result of acute toxicosis, more often after the oral intake of sublimate for the purpose of murder or suicide; cases of poisoning are not uncommon in children after accidental swallowing of sublimate tablets instead of candies or its solutions intended for bedbugs and disinfection. The main symptom is mercurial stomatitis (stomatitis mercurialis): on the 2nd-3rd day, an unpleasant metallic or sweet taste appears, a sensation of warmth in the mouth, bad breath (in severe cases, stench), swelling and redness of the gums (see Gingivitis) around the teeth, which become loose and sensitive, especially when chewing; sometimes thick saliva is secreted.

Severe phenomena are now rare, since upon the appearance of stomatitis the intake of mercury as a therapeutic agent is discontinued, and the phenomena subside. If, however, it was not discontinued (or the initial symptoms passed unnoticed), mercurial salivation (ptyalism mercurialis) joins in. The gums become inflamed, starting from the edges at the wisdom teeth; then the inflammation spreads along the line of the cheeks; a border of either a bluish, reddish, or leaden hue is formed, sometimes with plaques; the tongue, on the edges of which tooth impressions are noticeable, becomes swollen, soft, silver-colored; finally, the entire oral mucosa becomes inflamed, especially on the side on which the patient sleeps; the inflammation spreads to the fauces, pharynx, palate. The amount of saliva reaches up to 2-5 liters per day. At the indicated stage, the symptoms respond to treatment, but sometimes become persistent. With further progression of the process, gangrene and deep ulcerations of the oral mucosa join in, periostitis starting from the primary inflammation of the bone marrow; necrosis of the alveolar margin of the jaws with the dissolution of salts in the bones from an excess of lactic acid (ostitis mercurialis decalcificans); further, loss of teeth, difficulty in swallowing; intestinal phenomena are little expressed; phenomena of mild nephritis may be present. Rashes are very rare (so-called hydrargyria cutanea). Chronic poisoning, or mercurialism, most often occurs with prolonged inhalation of mercury vapors in industries (see below), in chemical laboratories, etc., less frequently arising as a result of treatment. Among medical poisonings, one must first of all indicate the use of gray ointment, the internal use of calomel, subcutaneous injections of insoluble preparations. The most sharp symptom of chronic poisoning (mercurialism) is mercurial tremor (tremor mercurialis), which begins with slight twitches in the fingers, then passes to the face and intensifies on the fingers. Such tonic muscle contractions are interrupted every 5 minutes by coarse jerk-like movements. With the course of poisoning, the tremor intensifies and spreads to the remaining muscles; the tremor reaches a maximum when the patient is under observation. This is the so-called intentional phase of tremor. The patient performs rough work somehow, but is incapable of fine work; in severe cases, tremor prevents walking and standing, drinking and eating, and even speech. Movements can become automatic. Tremor may pass on condition of removal from work and if it appeared before psychic changes; it often remains for many years. Alcoholism contributes to the occurrence of tremor. Charcot considers tremor a manifestation of hysteria, Guillain and Laroche consider lesions of the cerebellum or its pathways responsible for tremor. In very rare cases, tremor becomes choreatic or turns into convulsions disappearing during sleep, rest; pains in the joints and extremities appear; even more rarely—pareses, paralyses, sensory disorders, sometimes attacks of dizziness during which the patient falls (epilepsia mercurialis). Tremor may be without the presence of other symptoms and precisely when the adsorption of mercury vapors proceeds slowly over a long period; only gradually do the remaining phenomena develop. In the future, the course is complicated by mental disorders (erethismus mercurialis) or a special form of excitation existing in several forms. In severe cases, the following symptoms appear: the inability to speak and act normally in the presence of other people; excitability and nervousness, timidity, anxiety, confusion, uncertainty in work, loss of self-confidence (hypochondria mercurialis); insomnia, memory impairment or heavy dreams, headaches; mood worsens. In mild cases, mental changes are barely noticeable, there are complaints of fatigue and nervousness. Salivation and stomatitis are observed less frequently or only at the beginning of the disease. Among rarer symptoms, the following should be noted: abortions in women, menstrual disorders; lesion of offspring (high mortality of children under 1 year of age); a decrease in the number of erythrocytes and hemoglobin can be established in the blood, occasionally—granulation of the former and poikilocytosis; blood pressure is somewhat elevated; rashes of various character on the skin (hydrargyria cutanea); eczema (eczema mercurialis), urticaria, roseola, erythema; rashes can disappear and relapse; in case of poisoning after ointment rubs—gray-black coloration of the skin (hydrargyrosis); there may be an increase in bile production from liver irritation, the appearance of bile pigments in the urine; in very severe cases—ulcers of the large intestines, hyperglycemia and glycosuria, degeneration of the renal epithelium, renal cirrhosis; impairment of smell and hearing, nosebleeds, punctate hemorrhages. Death most often occurs from the accession of tuberculosis due to anemia, decline of strength and weight, and cachexia. In the preagonal period, cerebral phenomena can reach a maximum—complete loss of memory, amblyopia, psychoses with delirium and hallucinations. Salivation observed in subacute and chronic cases of poisoning is explained to a lesser extent by the local irritating effect of mercury vapors and the reflex to secretion arising therefrom; to a greater extent, this is connected with such an effect of mercury on the excretion pathways through the salivary and mucous glands of the oral cavity and fauces; at the same time, secretory nerves are excited (atropine stops salivation); mercury compounds excreted with saliva irritate and cauterize the entire oral mucosa; this is facilitated by the microflora of the cavity, especially rich in case of decayed teeth. Saliva swallowed irritates the gastric mucosa, leading to loss of appetite and digestive disorders. Intestinal lesions are associated with the local action of excreted mercury. Skin coloration and rashes are explained by the accumulation of mercury in the sites of excretion and in the sites of application, from where the process spreads to other areas of the skin. Kidney lesions depend on the irritating action of mercury on the excretion pathways from the body. Brain symptoms are associated with the direct action of mercury on the higher psychic and motor centers; anesthesia and neuritis are connected with this. The direct influence of mercury on metabolism and digestive disorders lead to a decline in nutrition and cachexia; changes in circulation depend on the latter. From pathologico-anatomical changes, it is necessary to note necrosis and degeneration in the cerebral membranes and ganglion cells of the anterior horns of the spinal cord and in the cerebral cortex; sometimes necrosis of the mucous membrane of the large intestine; slate-gray color of mucous membranes. Prophylaxis of subacute medicinal poisonings: introduction of distinguishing features of sublimate, correct choice of dose, preparation, mouth care, rubbing by the patients themselves to avoid poisoning of the personnel, taking into account contraindications in the treatment of mercury; elimination from medical practice of toxic methyl and ethyl compounds of mercury. Prophylaxis of chronic poisonings—see below. Treatment of subacute cases: mouth rinsing with potassium chlorate, tannin solution, hydrogen peroxide, lubrication of ulcers with chromic acid solution, tincture of myrrh, tincture of galls, lactic acid, lapis. For stomatitis, neosalvarsan into a vein or lubrication of the mouth with a 5-10% solution of it is recommended; for salivation and diarrhea—atropine (0.001); as a tonic—Methylene Blue, 0.02 several times a day in powders or solution. Treatment of chronic poisonings is symptomatic and accelerates the excretion of mercury with the help of potassium iodide and hot (sulfur) baths, dry-air and photoelectric baths. In recent years, Stock drew attention to the so-called micromercurialism, occurring after the inhalation of very small doses of mercury in the form of vapors, which does not give the classical picture of chronic poisoning and therefore often escapes the attention of doctors. Micromercurialism leads to a decrease in working capacity and affects well-being. Doses—fractions of a milligram with prolonged inhalation (for example, 0.002 mg per 1 m³ of air). Poisoning is observed in dentists and technicians, in people with filled teeth (silver and gold fillings), in laboratory workers, at enterprises for the manufacture of mercury devices, in medical personnel dealing with mercury preparations, etc. Symptoms: headaches, decline of strength, nervous anxiety, pressure in the head, dizziness, rhinitis, pharyngeal catarrh, salivation, gingivitis, rashes, hand and eyelid tremor, indefinite pains in various parts of the body, pressure in the liver region, occasionally diarrhea, memory impairment and depressed mood. Mercury is found in the urine and feces in amounts of tenths of a milligram (by micromethod): this testifies rather not to mercury poisoning, but to its circulation in the body. Symptoms of micromercurialism quickly disappear when a person is isolated from contact with sources of poisoning. Methods for detecting mercury in tissues and excreta.

For the qualitative determination of mercury in tissues, the following methods are used: 1) destruction of organic substances according to the universal method of Fresenius and Babo with chlorine at the moment of its formation under the action of potassium chlorate on hydrochloric acid, or according to the Stepanov method with sulfuric acid and ammonium nitrate; 2) after the destruction of the organic material, treatment of the filtrate with hydrogen sulfide and washing of the precipitate; 3) treatment of the latter with polysulfides and concentrated ammonia solution, filtration; 4) treatment of the precipitate with concentrated hydrochloric acid and potassium chlorate, evaporation, and dissolution of the residue in water, followed by testing this solution for mercury using the following qualitative reactions: a) formation of an amalgam of mercury and copper when a drop of the aqueous solution is applied to a copper plate, b) formation of a white precipitate of HgCl, turning gray due to the precipitation of metallic mercury after mixing a drop of the solution with several drops of stannous chloride solution, c) formation of a red or yellow ring of mercuric iodide in a heated tube with a crystal of iodine and copper spirals that have been in the test solution for twenty-four hours. Testing for corrosive sublimate: extraction with ether, its evaporation, dissolution of the residue in water, and reaction for mercury and chloride ions. To determine mercury in vomit, Kobert's method is also used: the finely stirred, weakly acidified contents are poured into two vessels, and a shiny zinc plate is immersed in one, and an iron plate in the second; the blackening of the first and whitening of the second indicate the presence of mercury. Quantitative determination of mercury (in large quantities): 1) saturation of a certain part of the test solution (after destruction of organic substances) with hydrogen sulfide, filtration, treatment of the filtrate with concentrated hydrochloric acid and bromine, removal of the latter by a current of carbon dioxide; new saturation with hydrogen sulfide, filtering the precipitate into a Gooch crucible, washing with water, alcohol, removal of sulfur with carbon disulfide, and the latter with alcohol and ether, and drying the crucible at 100° to constant weight; 2) the method of Richards and Singer—deposition of mercury on copper spirals, washing it with water and alcohol, drying and weighing, calcination in a stream of hydrogen, re-weighing—the difference in weight corresponds to the amount of mercury; 3) for small amounts of mercury, a ring of mercuric iodide is obtained from a certain amount of solution under certain conditions; comparison with standard rings of mercuric iodide (from 0.5, 0.4, 0.3, 0.2, 0.1, 0.05, etc. mg) prepared in the same way; 4) the method of Autenrieth and Montigny—colorimetric determination in the form of a colloidal solution of mercuric sulfide; applicable in the absence of silver, copper, zinc, and bismuth. To determine mercury in urine, Stukovenkov's method is most often used (see Urine). In recent years, two more methods have been proposed for detecting minimal amounts of mercury in urine (and feces): the Stock and Zimmerman method, which consists of colorimetric determination; the mercury isolated on a copper plate is dissolved in chlorine water, and 1 drop of a saturated carbamide solution and 1 drop of a diphenylcarbazone solution are added to the solution, and the blue color of the solution is compared with the color of a liquid prepared in the same way containing mercury in an amount of 0.1 mg or 0.5 mg; sensitivity—up to 0.04 mg; the Bodnar and Szep method boils down to isolating mercury and copper on iron wire after adding copper sulfate to the mercury solution; the mercury gathers into a drop, is cleaned with alcohol, and the diameter is determined under a microscope, and the weight by formula. The detection of mercury in the air is based on the mercuric iodide test (see above) after drawing the air through hydrochloric acid and bromine and isolating the mercury on a metal spiral. Application of mercury preparations. 1. In syphilis—see Syphilis. 2. Protozoan diseases of the malaria or trypanosomiasis type are less amenable to treatment with mercury than syphilis. 3. As a bactericidal agent, mercury was used in acute febrile diseases, but now only in acute iritis. 4. In the form of mercurochrome in septic processes. 5. As a laxative (see Calomel). 6. Diuretic in edema of cardiac origin (see Novasurol, Salyrgan, Calomel); the effect is weaker in renal and hepatic edema. 7. Externally as a disinfectant and antiseptic agent (see Corrosive sublimate) in surgery, urology, and eye practice for blepharitis, conjunctivitis, keratitis. 8. In skin diseases, mainly of parasitic origin (e.g., pityriasis versicolor, pediculosis, lichen, sycosis, pruritus, etc.), as well as in non-parasitic diseases, e.g., eczema; in all these cases, the disinfecting action of mercury is combined with an irritant one; mercury has the same significance in ulcers, condylomas. 9. In diseases of the cervix uteri—cauterization with mercury preparations. 10. As a counter-irritant, resolving, and anti-inflammatory agent in phlegmons, lymphadenitis, etc. Mercury treatment is contraindicated in scurvy, dysentery, severe heart diseases, in a bad state of the gums, acute nephritis; severe dyspepsia is a contraindication for the administration of mercury per os; rubbing ointments into the scrotum, in skin processes, and in infants is prohibited. It should be used with caution in severe cachexia, weakness, anemia, if the latter are not caused by syphilis; avoided in poor digestion and tuberculosis due to the danger of worsening the process from gastrointestinal disorders; in severe nephritis, in the last months of pregnancy (danger of miscarriage), albuminuria. When taking iodide salts, mercury ointments and powders are prescribed with great caution due to the possibility of the formation of mercuric iodide with a strong caustic effect. Mercury preparations. I. Containing metallic mercury. Hydrargyrum depuratum (Ph. VII), purified metallic mercury; was used for intestinal obstruction; now very rarely prescribed per os in pills of 0.15 per day for lues or in the form of suppositories of 0.02–0.04 per day for rectal syphilis. It is part of a number of preparations—Ung. Hydr. cinereum (Ph. VII), Ung. neapolitanum, gray mercury ointment; upon storage, fatty acids are formed, imparting an acidic reaction to the ointment; at the same time, part of the mercury passes into combination with these acids, which facilitates its absorption; therefore, when preparing a new ointment, it is advisable to add a certain amount of the old one; to accelerate the formation of these compounds, ozone-containing turpentine is sometimes mixed in. It is used for lues in the form of rubs of 2–5 g for adults and 0.2–1.0 g for older children, in skin diseases, mainly of syphilitic origin, in glandular tumors, for lubricating the anus for pinworms, sometimes for scabies, often for pediculosis pubis. Instead of the officinal ointment, mercury ointments on vaseline, mollisin, resorbin have been proposed; some of them are better absorbed and therefore act faster; mercury-vasogen ointment (50% mercury), mercury resorbin (Bayer company) or Ledermann's resorbin ointment prepared from gray ointment (33¹/₃% and 50% mercury) (Resorbin is a fat emulsion containing water, neutral oil, lanolin, wax). Ung. Hydr. duplex, double gray mercury ointment (50% mercury), Aachen gray ointment of the composition: Hydr. puri 100.0, Lanolini anhydrici 15.0, Ol. Olivar. 3.0, Axungia porci 112.0, Adeps bovinus 70.0. Ung. Hydr. compositum contains 12% mercury and camphor. Hydrargyrum cum Creta, mercury with chalk or gray powder, obtained by triturating mercury with chalk and honey; light gray powder, slightly moist, odorless, sweetish taste, contains 33–38% mercury, partly in metallic and partly in oxide state; prescribed per os 0.25 as a laxative and intestinal disinfectant, for lues 0.05 per os three to five times a day. Oleum cinereum (griseum), Mercinol, gray mercury oil, suspension of mercury (20–40 parts) in liquid paraffin (4 parts) or in lanolin (3 parts) and olive oil (4 parts); for lues intramuscularly 0.1–0.2 one to two times a week for 5 weeks with equal intervals. Emplastrum Hydrargyri (mercuriale) (Ph. VII), mercury plaster of the composition: purified mercury—2 parts, anhydrous lanolin—1 part, simple lead plaster—6 parts, yellow wax—1 part; for chancres, syphilitic ulcers, gummas; for lues, Emplastrum resinosum Unna is also used. Sapolentum Hydrargyri, mercurial soap or gray mercurial soap (Unna) with 33¹/₃% mercury; dose 3–4 g; rubbed until it forms a lather on skin moistened with warm water, then drying; replacement for gray ointment. Hydrargyrum sulfuratum rubrum, Cinnabaris, red mercuric sulfide, cinnabar; as an anti-inflammatory in folliculitis, pyoderma, dermatomycosis in 1–10% ointments; as a caustic in skin neoplasms and diseases in the form of Lassar's paste of the composition: 1% cinnabar, sublimed sulfur, and bergamot oil on yellow vaseline, or in the form of a paste: white arsenic 1.0, cinnabar (artificial) 3.0, vaseline 30.0; it is part of Decoctum Zittmanni (from Rad. Sarsaparillae), used for lues. Hydr. colloidale sulfuratum, colloidal solution of mercuric sulfide; for lues intramuscularly 2–4 cm³ every two to three days. II. Mercurous compounds.

Hydrargyrum chloratum, Calomel, calomel (see). Mechnikov's ointment, 33¹/₃% calomel ointment, a prophylactic agent for lues. Vetrashevsky's calomel soap (50%) as a disinfectant and antiluetic agent in the form of rubs of 3–4 g into moist lathering skin. Calomel solution (1 part) in traumaticin (4 parts), mercury lacquer, a topical agent for lues carried in sachets. Emplastrum calomelanos, calomel plaster, for lues. Calomel diaspora, colloidal calomel solution for intravenous infusions in syphilis. Lotio Hydrargyri nigra, black mercury lotion, prepared from calomel by the action of lime water; topically in the form of compresses and washings for skin lues (shake before use). Hydrarg. jodatum flavum (Viride), Protojoduretum, Hydrargyrum jodidum flavum, yellow or green mercury iodide, occasionally used for lues: 0.01–0.05 several times a day in powders with opium or in pills; for children up to 1 year – 0.005; for children 5 years old – 0.01; 2–5% ointment is used for dressings on syphilitic tumors. Solutio Donovani – see Donovan's solution. Hydrargyrum nitricum oxydulatum, mercurous nitrate, colorless plates and needles, soluble in water, rarely used. III. Mercury oxide compounds. Hydrargyrum oxydatum flavum (Russian Pharmacopoeia VII), Hydrargyrum via humida paratum, Hydrargyrum praecipitatum flavum, yellow mercury oxide, a fine yellow amorphous powder, insoluble in water; dose 0.02 (0.06); used in the form of eye ointment. Unguentum Hydrargyri flavi, Unguentum Hydrargyri oxydati (Russian Pharmacopoeia VII), yellow mercury ointment containing 2% yellow mercury oxide; yellow-orange color, odorless, prepared ex tempore, protected from the action of light; used for inflammatory processes of the eyes and sometimes for syphilitic ulcers, condylomas, and chancres. Hydrargyrum oxydatum rubrum (Russian Pharmacopoeia VII), red mercury oxide, or Hydrargyrum oxydatum levigatum, a very fine, crystalline, yellowish-red powder, insoluble in water. Maximum dose (Russian Pharmacopoeia VII) 0.02 (0.06); used in powders or pills, more often externally as a powder or 10% ointment (not for the eyes) – Unguentum Hydrargyri oxydati rubri. Hydrargyrum bichloratum, sublimate (see). Hydrargyrum bichloratum cum Kalio jodato solutum, solution of mercuric chloride and potassium iodide, Mayer's reagent, a colorless liquid of neutral reaction, prescribed for the tertiary period of lues. Neisser and Siebert's mixture contains 0.3 sublimate, 1.0 NaCl per 100.0 starch-gelatin-alcohol-glycerin mass; a prophylactic agent for lues. Soluisin, a solution of the composition: sublimate – 0.3, sodium iodide – 14.0, water – 20.0; for lues 1–2 cm³ into a vein and into a muscle. Liquor Hydrargyri albuminati is obtained by mixing 68 g of sublimate solution (5.6) and sodium chloride (5.0) with 25 g of fresh egg white; for lues per os (shake before use). Lotio Hydrargyri flava, yellow mercury lotion, prepared from sublimate under the action of lime water, for lues in the form of compresses and washings (shake before use). Hydrargyrum amidato-bichloratum, amidomercury chloride (Russian Pharmacopoeia VII), Hydrargyrum praecipitatum album, white precipitate, Hydrargyrum bichloratum ammoniatum, ammoniated mercury dichloride, or mercurammonium chloride, a white, amorphous powder insoluble in water and alcohol; used in the form of Unguentum Hydrargyri praecipitati albi (Russian Pharmacopoeia VII), white mercury or amidomercury chloride ointment, prepared ex tempore; indicated for syphilis, eye and skin diseases (as a cosmetic), and against parasites (pinworms – smearing of the anus, pediculosis). Unguentum Averini, Unguentum Hydrargyri praecipitati albi Averini: amidomercury chloride – 6 parts, lard – 48 parts, bergamot oil – 1 part, and lavender oil – 1 part; used instead of white ointment. Hydrargyrum bijodatum, Hydrargyrum jodatum rubrum, mercury diiodide, red mercury iodide (Russian Pharmacopoeia VII), a fine, bright red powder, odorless and tasteless, almost insoluble in water, soluble in alcohol, ether, chloroform, glycerin, solutions of iodide and chloride salts; contains 14% mercury; by itself is rarely prescribed – in pills of 0.005–0.01; formed in Mayer's reagent, held in solution by an excess of potassium iodide; sometimes used for lues in the form of subcutaneous injections of a solution: potassium iodide – 0.35, mercury diiodide – 0.5–1.0, water – 50.0; ¹/₂–1 cm³ per day, or in the form of Biett's mixture (see Biett's mixture). Maximum dose (Russian Pharmacopoeia VII) 0.02 (0.06). Unguentum Hydrargyri bijodati (4%) is used for syphilitic skin lesions. Hydrargyrum bibromicum, mercury dibromide (the latter 55.5%), for subcutaneous and intravenous injections for lues in a 2% solution. Hydrargyrum nitricum oxydatum, mercuric nitrate, a white substance, completely insoluble in water, not used per se; comes in the form of ointments. Unguentum Hydrargyri nitrici, mercuric nitrate ointment, lemon-yellow color; used for conjunctivitis, syphilitic and gangrenous ulcers. Unguentum Hydrargyri nitrici diluti, mercuric nitrate ointment diluted with lanolin or oil (1:5); indicated for eye diseases. IV. Organic mercury preparations. Hydrargyrum salicylicum, mercury salicylate (Russian Pharmacopoeia VII), intramolecular salt of mercurosalicylic acid, an amorphous white powder, odorless and tasteless, almost insoluble in water and alcohol, contains 50% mercury; used for lues into a muscle in the form of a 10% suspension in olive oil or vaseline oil weekly or every 3–4 days at ¹/₂–1 cm³ for a month; sometimes per os at 0.01–0.02 in pills; maximum dose (Russian Pharmacopoeia VII) – 0.02 (0.06). Asurol, asurol, double salt of mercury salicylate and sodium amidooxyisobutyrate, a white powder containing 40.3% mercury; soluble in water; for lues into a muscle and under the skin in a 5–10% solution at ¹/₂–2 cm³ every 3–4 days (¹/₂ cm³ = 0.02 mercury); per course – 12–15 injections. Embarin, a yellow 6.75% solution of sodium mercury salicylyl sulfonate containing 3% mercury; into a vein and muscle (with the addition of anesthetic akoin); ¹/₃–1 cm³ every 1 day for lues; course of 16–20 injections. Hydrargyrum cyanatum, mercury cyanide (Russian Pharmacopoeia VII), white, translucent crystals, soluble in water; contains 80% mercury; as a disinfectant and antiseptic in doses of sublimate; for lues per os at 0.005–0.01 or under the skin and into a vein in a 1% solution; sometimes for diphtheria in the form of gargles; as a diuretic at 0.04–0.05 per os; maximum dose (Russian Pharmacopoeia VII) – 0.01 (0.03). Cyarsal, cyarsal, potassium cyanomercuric salicylate, a colorless powder, soluble in water, with 46% mercury; for lues a 1% solution into a vein with novarsenol 2 times a week – 0.04 of the second and ¹/₂–2 cm³ of the first; per se in ampoules (2 cm³ of a 1% solution) into a muscle. Hydrargyrum oxycyanatum, basic mercury cyanide (Russian Pharmacopoeia VII), a white or slightly yellowish crystalline powder, poorly soluble in water; for lues per os at 0.005–0.01 three times a day or in a 1% solution at 1 cm³ under the skin and into a muscle; as a disinfectant in aqueous solutions 1:1,000–1:3,000 in urology; in the form of blue tablets for hand disinfection (solution 1:1,000–1:8,000); as a prophylactic for lues in the form of a 0.1% ointment consisting of mercury oxycyanide, thymol, and calomel, for introduction into the canal; maximum dose (Russian Pharmacopoeia VII) – 0.01 (0.03). Hydrargyrum leinicum, mercury oleate, compound of mercury oxide and oleic acid, mercury oleate, a yellow substance of astringent consistency; used in a 5–10% ointment in the same cases as gray ointment. Mercurochrome 220, mercurochrome, disodium salt of dibromoxymercurifluorescein (25% mercury), iridescent green plates, soluble in water; as a bactericidal and antiseptic in a 1–4% aqueous or 2% alcohol-acetone-aqueous solution topically; into a vein a 1% solution at the rate of 0.005 per 1 kg of weight for sepsis and for disinfection of the urinary tract (action on the excretion tracts); in an enema for colitis at 60 cm³ of a ¹/₂% solution.

Novasurol (see). Saligenin (see). Neptal, a synthetic mercury preparation, o-acetyloxybenzoic acid hydroxymercuripropanolamide, C₆H₄(OCOCH₃)CONHC₃H₅(OH)HgOCOCH₃, structurally similar to salyrgan; obtained by treating mercuric acetate with a salicylic acid derivative, allylsalicylamide; insoluble in water, but rendered soluble by introducing the CH₂CO₂Na group into the phenolic hydroxyl; used in a 10% solution, each 1 cm³ of which contains 0.03 g of mercury, intravenously and subcutaneously; introduced as a diuretic due to the toxicity of novasurol; the effect is greater than that of salyrgan, sometimes repeated; mechanism of action is like that of all mercurial diuretic preparations. Hydrargyrum succinimidatum (succinimidicum, imidosuccinicum), mercury succinimide or mercury cinnamate, a white crystalline powder, soluble in water; subcutaneously for lues at 0.01 pro die. Hydrargyrum tannicum oxydulatum, mercury salt of tannic acid, tannate of mercurous oxide, a green-brown powder insoluble in water; for syphilis at 0.1-0.05 two to three times a day in powders and pills for 6-8 weeks, for children 0.01 for each year of age. Mergal, a compound of cholic acid mercuric oxide (1 part) and protein tannate (2 parts), a pale yellow powder insoluble in water, dispensed in gelatin capsules; each containing 0.05 of the first and 0.1 of the second compound. Hydrargyrum bichloratum carbamidatum, solutum, see Sublimate. Hydrargyrum arsanilicum, see Arsenic. Hydrargyrum jodokakodylicum, iodocacodylic mercury, a compound of mercuric iodide and sodium cacodylate according to Brocq's formula: Hydr. bijod. rubr., Natr. jodat. sicc. et puri aa 0.3, Natr. kakodyl. 0.9, Aquae 30.0; for lues intramuscularly and subcutaneously; especially recommended for malignant syphilis with anemia and cachexia. Enesol, Hydrargyrum methylarsenicicosalicylicum, enesol, arsenic-salicylic mercury, soluble in water (38.46% mercury and 14.4% arsenic), a white amorphous powder. Hydrargyrum peptonatum, peptone mercury, for lues 1 cm³ of a 1% solution subcutaneously. Mercurol, a compound of nucleic acid and mercury (10% of the latter); per os at 0.05-0.1 twice a day for lues; for gonorrhea, irrigations with a 2% solution. Hydrargyrum colloidale, Hyrgolum, colloidal mercury, hyrgol; an amorphous dark brown mass, soluble in water; for lues in the form of a 10% ointment at 2.0 per day; subcutaneously a 1-2% solution; contains impurities. In addition to the indicated preparations for injections, the following have been proposed: carbolate of mercury, aminopropionate of mercury, asparaginate of mercury, glycocollate of mercury, resorcinol-acetic mercury, diphenyl mercury, tribromophenyl mercury, and tyrosine mercury. The diuretic effect of a number of organic mercury compounds has been experimentally proven. Chemical (prescription) incompatibilities when mixing mercury and its salts: with chlorides, bromides, and iodides (formation of corresponding compounds, and in the case of ammoniated mercury, the possibility of ignition and explosion), alkalis, alkaloids, tannin (precipitates), organic substances (decomposition or formation of new compounds).

A. Kuznetsov. Mercury as an industrial poison has lost its significance for a number of industries over the last 25-30 years, because it has been and is being replaced by other substances. Such industries include: mirror manufacturing, where mercury was completely ousted and replaced by silver nitrate about 30 years ago; fire-gilding and silvering, which was previously performed using mercury amalgams of these metals, is now performed using galvanoplasty; in the manufacture of incandescent lamps, mercury pumps are being replaced by oil pumps. Among the industries where mercury and its compounds still play the role of an industrial poison, one can name: mining—the extraction of mercury and in particular obtaining it from ore, the manufacture of felt and felt hats, the manufacture of thermometers and other physical instruments, pharmaceutical apparatus, mercury fulminate, electric meters, electric lamps (insofar as mercury pumps have not yet been completely eliminated); furthermore, dentists, disinfectants, and others deal with mercury. Mercury can enter the body under occupational conditions in various ways: when manipulating certain preparations (sublimate, grey mercury ointment) it is absorbed through intact skin; mercury amalgams and salts are pulverized, and the dust enters the respiratory tract; from contaminated hands, mercury enters the intestines, vapors enter the respiratory tract or, condensing in the upper respiratory tract, enter the intestines with mucus and saliva (this pathway is of the greatest importance); finally, cases have been noted where mercury vapors that settled on a worker's clothing subsequently evaporated again. Regarding the fate of mercury in the body, acute and chronic poisoning, see above. Toxic doses. Sensitivity to mercury and its various compounds varies within very wide limits among different individuals; some can tolerate doses of sublimate and other mercury preparations up to 0.5 g, while others die from 0.1 g. According to Gotlin, inhalation for several months of 0.4-1 mg daily is sufficient to cause chronic poisoning; according to Henderson and Haggard, daily inhalation of 0.7-1.28 mg for 2-3 months is sufficient for the same. According to Teleky, these quantities are much smaller: daily inhalation of 0.04-0.1 mg of mercury for several years is sufficient for severe chronic poisoning to develop. In a work published in 1926, Stock made a sensational report regarding the possibility of poisoning in individuals wearing dental fillings made of mercury amalgams in their mouths, whose bodies absorb thousands and ten-thousandths of a milligram of mercury daily. These amounts already prove sufficient to cause phenomena of chronic poisoning in individuals with hypersensitivity. Fühner, who compiled a summary of all data on this issue, sets the limit of the daily introduced amount of mercury, below which poisoning is hardly possible, at 0.1 mg, and for individuals with hypersensitivity—0.05 mg. Acute poisoning under occupational conditions is quite rare; it is possible among disinfectants who spray and wash rooms with strong sublimate solutions, among those working in chemical laboratories, in the production of mercury fulminate—during its explosions, upon the formation of fulminating compounds with dimethyl and diethyl, etc. Much more frequently, workers in production exhibit the following forms of poisoning: subacute, where phenomena on the part of the oral cavity predominate (developing as a result of inhaling metallic mercury vapors); chronic, where tremor and other nervous phenomena and cachexia come to the foreground (observed in individuals exposed to mercury compounds—amalgams, salts, etc.); Teleky also distinguishes an intermediate form, when tremor is present along with phenomena on the part of the oral cavity (it develops when a large amount of mercury enters an already poisoned body simultaneously). Statistical data. Compared to the 19th century, mercury poisoning—due to the banishment of mercury from the most dangerous industries—has significantly decreased; nevertheless, the number of poisonings observed even at present is quite large. Thus, in Switzerland, 8 cases were registered for 1917, 10 in 1919, 10 in 1920, 12 cases in 1927, etc.; in Germany from January 1917 to May 1918—11, in 1927—90, in 1928—66, in 1929—91 cases; in England from 1899 to 1912—33, in 1913—14, in 1914—10, in 1915—6, in 1916—18, in 1917—17, in 1918—9, in 1919—7, in 1920—5, in 1921-22—6 cases; of these, in the production of mercury fulminate—52, felt—25, hat-making—23, electric meters—25, chemical industry—21, in gilding—8, etc. In 1925-29, 3-5 cases were registered annually. For the USSR, from 1924 to 1929, a total of 109 cases of mercury poisoning were registered, of which the highest number was provided by workers of the Nikitovka Mercury Plant; furthermore, cases of poisoning took place in the production of thermometers, electric lamps, among disinfectants, etc. Among the industries where the danger of mercury poisoning is especially great and cases of poisoning occur (and have occurred) most frequently, we note the following. Extraction of mercury. It is concentrated in a few places: Spain (Almadén), USA (California, Texas), Italy (Monte Amiata), Yugoslavia (Idrija), USSR (village of Nikitovka, Bakhmut District). The average annual mercury production is about 4,000 tons. Mercury is mined underground in the form of sulfur compounds interspersed in the ore. These compounds are non-volatile, do not dissolve in body fluids, and therefore working underground does not present a particular danger in terms of poisoning. An exception is cases of mining ore in the form of silver shale, in which metallic mercury is interspersed. When breaking such ore, mercury is sprayed, evaporates, and causes poisoning of the stope miners. Ore roasting to extract mercury from it is carried out differently. With old methods (roasting in heaps, in muffle furnaces, Spanish Bustamante furnaces), up to 50% of the mercury escaped into the air and it presented a tremendous danger not only to the workers, but also to the surrounding population. A newer method consists in roasting ore in shaft, flame, and reverberatory furnaces, which are equipped with various safety devices; but even here, during loading, monitoring the roasting, pushing the ore through, and unloading it from the furnaces, mercury vapors are released in significant quantities. From the furnaces, mercury in the form of vapors goes through a system of condensation pipes, and only part of it precipitates in the form of metallic mercury, while the greater part in the form of a deposit ("Stupp") mixed with coal and products of incomplete combustion settles on the pipe walls. This deposit is removed every 2-4 weeks, with a lot of dust containing mercury being released. Mercury is then squeezed from the deposit in special presses. The latter two jobs are the most dangerous. Teleky, who surveyed the mercury mines of the town of Idrija in 1912, found that almost the entire population engaged in the mercury business gives the impression of being feeble and degenerating; among the workers, morbidity and mortality from tuberculosis are high. The number of poisonings fluctuated within wide ranges, yielding huge figures in some years—in various years between 1874 and 1908 it fluctuated from 5 to 151 with an average number of workers at the plant of 250 people. Poisonings in general were not particularly severe and were subacute in character; only those constantly working at the plant had severe forms with cachexia and nervous phenomena. Approximately analogous data were published by Giglioli for the mine and plant in Monte Amiata. In the USSR, until recently, the only place for mercury extraction is the mine near the village of Nikitovka; there is also a plant equipped with furnaces of newer systems—flame and reverberatory. However, working conditions at this plant remained very unfavorable until recently: thus, according to Navrotskiy's study in 1926, mercury was found in 1 m³ of air in the soot-cleaning room at 4.5–6.5 mg in summer, 32–38 mg in winter; at the ore charging station at 2–3.3 mg in summer, 36–58 mg in winter; during ore smelting at 1–5.2 mg in winter. Over 9 months with 120 workers, 12 cases of chronic poisoning were registered. The expedition of the Kharkov Institute of Pathology and Hygiene of Labor, which clinically examined 108 workers of this plant in 1927, of whom 73% had worked at the plant for no more than a year, found in all examined individuals pallor of the skin and a significant lag behind normal weight (by 3–4 kg), gum lesions in 64%, enlargement of the submandibular glands in 61%, excessive salivation in 50%, diarrhea in 61%, acute tenderness in the region of the small intestines in 75%, painful liver changes in 70%, tremor of the upper extremities in 33%, depressive neurasthenia in 71%, etc. The production of felt and felt hats yields the highest number and furthermore the most severe cases of poisoning.—In the manufacture of thermometers up to the present time, despite the rationalization of the production process, it has not been possible to completely prevent the release of mercury vapors into the air.—Manufacture of electric lamps. Mercury pumps are used here to evacuate air from already finished lamps.

When using pumps of the old system, where mercury flowed down glass capillaries and thereby entrained air, the danger of mercury poisoning was great, and cases of poisoning occurred here quite frequently. Subsequently, metal pumps began to be used, where the danger of poisoning existed during the cleaning of the pumps and the mercury itself; a significant amount of mercury vapors was found in the indoor air (in 1927, from 3 to 15 mg per 1 m³ of air in Moscow factories). In recent years, oil pumps have begun to be introduced instead of mercury. - Production of mercury fulminate - see Fulminating mercury. - Production of chemical preparations: calomel, corrosive sublimate, mercury iodide, etc. Here one constantly has to deal with mercury and its compounds; furthermore, during the process itself, especially during sublimation, mercury vapors are released. The number of workers taking part in this production is small, but cases of poisoning occur repeatedly (see statistical data above). - Fire gilding. The object to be gilded is moistened with a solution of mercury in nitric acid, then smeared with gold amalgam using a brush, after which it is placed in a furnace for a few minutes, where the mercury volatilizes in the form of vapor, and the gold remains on the surface. The object is taken out, wiped, smeared with amalgam again, placed in the furnace, etc.; this process is repeated several times. The amount of mercury used and evaporating in this process is very large, and poisoning is almost inevitable; it sets in after just a few days and is subacute in nature. Poisoning from gilding was already described in the 16th century; in the first half of the 19th century, this production yielded the greatest number of mercury poisonings. In the middle of the 19th century, the electroplating method was adopted almost everywhere, but later it was found that gilding by the fire method holds more firmly, and in the last 20-25 years it has begun to be used again. - Mirror production - see Mirrors - mirror production. Prophylaxis. First place must be given to the complete removal of mercury from all industries where it can be replaced by other substances. In our USSR, basic attention in this regard should be paid to the felt industry (replacement of mercury with caustic potash, which has already been fully accomplished in recent years) and electric lamps (replacement of mercury pumps with oil pumps). Furthermore, production processes must be rationalized: in mercury plants, outdated equipment should be replaced with newer and more improved ones, such as improved Cermak-Spirek furnaces, Exeli extractors, which make it possible to use all condensate residues while avoiding workers' contact with mercury. A temperature of no higher than 15-16° should be maintained in workrooms. The generated vapors must be removed by means of vigorous ventilation. Where it is not possible to avoid the release of a large amount of vapor, workers must wear respirators. For more details on prophylactic measures, see individual industries: fulminating mercury, hat-making, thermometers, etc. Very serious attention should be paid to the preliminary selection of workers, periodic control of their health, and detailed instruction. Individuals showing symptoms of poisoning should be transferred to other work not involving the use of mercury, temporarily or (in case of repeated poisonings, the elderly) permanently. In hazardous jobs (e.g., a mercury plant), a periodic transfer of workers to work not associated with the danger of mercury poisoning is very advisable. Adolescents must not be allowed to work involving the danger of mercury poisoning. Rational special clothing and special respirators are of very great importance. (The Institute of Labor Protection has developed a type of respirator in which complete absorption of mercury vapors takes place.) In the USSR, persons working with mercury enjoy a 6-hour working day and additional leave; women and adolescents are not allowed to do hazardous work. Treatment. In pronounced cases of poisoning, patients must be removed from work with mercury. Of the medicinal agents, good results are obtained by the use of sodium hyposulfite in solution, 1 g per day, sometimes in combination with bismuth. For the treatment of stomatitis, a 10% solution of chromic acid or an 8% solution of zinc chloride is recommended. In addition, general strengthening treatment is required; in a number of cases, the use of symptomatic remedies is necessary. A good, lasting effect is obtained by treatment with natural sulfur baths (Pyatigorsk, Matsesta). N. Rosenbaum. Detection of mercury in medico-chemical cases and in occupational poisoning. The objects of investigation for mercury in medico-legal cases are parts of internal organs, vomit, and urine. Investigation of the latter is especially important in cases of chronic poisoning and in all suspicions of mercury poisoning. Often, the body's fight against the poison continues for 1–3 weeks and ends in death, which leads to the finding of only traces of mercury in the internal organs of the corpse. - Detection in internal organs and vomit. After destruction of the test objects (see Poisons, isolation), mercury is precipitated with an excess of hydrogen sulfide (along with other metals of the hydrogen sulfide group). The sulfur compounds are treated with concentrated nitric acid mixed in half with water. The insoluble mercury sulfide is separated and dissolved in the smallest possible amount of concentrated hydrochloric acid with the addition of potassium chlorate. The solution is evaporated on a water bath at 40-50°, the residue is dissolved in a small amount of water, and reactions for mercury are performed with the solution: 1) when a drop of the solution is applied to a freshly cleaned brass plate, a gray spot is obtained, which upon careful rubbing with filter paper becomes silvery-shiny; 2) when a drop of the solution is mixed with a few drops of a freshly prepared solution of stannous chloride, a white, graying precipitate is obtained; 3) brass spirals (made of thin wire) are placed into the solution; a day later, the spirals are washed with water, alcohol, ether, heated in a thin tube with a crystal of iodine, and a red ring of mercury iodide is obtained; the resulting ring makes it possible to judge the amount of mercury. Upon microscopic examination, the coating of the ring has the appearance of red square octahedra. In cases where death from poisoning by mercury preparations occurred a long time after the poisoning, the insignificant amounts of mercury remaining in the organs are no longer precipitated by hydrogen sulfide. In these cases, after the destruction of parts of the viscera with hydrochloric acid and potassium chlorate and the thorough removal of chlorine, it is necessary to precipitate mercury on brass spirals followed by sublimation with iodine of mercury iodide, as described above. To detect mercury in urine, it is precipitated by heating with chicken egg white (as is done in clinical practice according to Stukovenkov). The coagulated protein together with the brass spirals is placed in hydrochloric acid, proceeding further as described above. - In occupational poisoning, the detection of mercury in the urine of workers and the study of the air take place. For the latter, a certain volume of air is drawn through absorbers with concentrated hydrochloric acid containing an excess of bromine. Bromine is removed by passing carbon dioxide from the solution, mercury is precipitated onto a brass spiral, and then sublimed in the form of mercury iodide, as described above. Comparison with standards also serves for quantitative determination.