For the purpose of demonstrating the presence of corrosive sublimate in a highly coloured liquid, or one loaded with organic matter, it is necessary to agitate it for some minutes with an equal volume of ether. After repose for a short time, the ethereal solution is decanted, and allowed to evaporate spontaneously. The residuum (if any) contains the corrosive sublimate, which, after being dissolved in distilled water, is readily recognised by the above characteristics.
When the substance under examination consists of food, or the contents of the digestive canal, or of animal tissue, it is in general necessary to destroy the organic matter in a nearly similar way to that described under Arsenious acid. The process adopted by Devergie for this purpose consists in dissolving the substance in concentrated hydrochloric acid, and passing a stream of chlorine through the liquid.—Flandin first carbonises the mass
with 1⁄3 or 1⁄2 its weight of concentrated sulphuric acid, at 212° Fahr., and then saturates the acid in the cold, with dry ‘chloride of lime,’ added in fragments, assisting the action by stirring, and further adding, by degrees, as the matter thickens and becomes white, a sufficient quantity of distilled water.—Lassaigne boils the suspected mixture for some time with a solution of sodium chloride; a method which, according to Orfila, is not sufficiently delicate to withdraw minute portions of mercury from flesh.—Millon agitates organic liquids (more especially blood, milk, &c.) in large flasks containing gaseous chlorine, which is frequently renewed.—Orfila either dissolves the matter in aqua regia, and passes a stream of chlorine through the liquid, or he carbonises it by means of concentrated sulphuric acid, in close vessels.—Personne proceeds by a similar method, but avoids raising the temperature of the substances operated on.—Reveil employs either the last method or that of Millon. In all cases it is advisable to operate in close vessels, on account of the volatility of the bichloride; Orfila’s apparatus consists of a matrass, provided with a bent tube, the one end of which is plunged into a jar of cold distilled water. The corrosive sublimate is found both in the volatilised matter and in the carbonised residuum, and is extracted from the latter by boiling it for 15 or 20 minutes in aqua regia.
When the organic matter has been destroyed by any of the above processes, and a colourless and filtered solution in distilled water obtained, the usual tests may be at once applied. But in this way we can only detect the presence of mercury, but are unable to decide in what way it has entered the system, although we may infer it from other circumstances. It is, therefore, absolutely necessary, in all medico-legal investigations, to previously employ ether (see above), in order that we may be enabled to examine the deleterious matter in its original form, or that in which it was swallowed.
Uses, &c. Mercuric chloride is employed as an alterative, diaphoretic, and resolvent, in the chronic forms of secondary syphilis, rheumatism, scrofula, cancer, old dropsies, numerous skin diseases, &c.; and externally, as a caustic, in cancer, and made into an ointment, lotion, or injection, in a vast number of skin diseases, ulcers, gleet, &c., and as a preventive of contagion. It acts quicker than the other preparations of mercury, and it is less apt to induce salivation; but it has been said that its effects are less apparent.—Dose, 1⁄10 to 1⁄4 gr., either made into a pill, or in solution. It is highly poisonous, and must be exhibited and handled with the greatest caution. Its use is contra-indicated in cases complicated with pulmonary affections or nervous derangement.
Pois.—1. Symptoms. Strong coppery or metallic taste; intense pain in the mouth, pharynx, œsophagus, stomach, and intestines;
nausea, vomiting (often bloody), diarrhœa, and (sometimes) violent dysentery (these evacuations are generally more frequent than in poisoning by other metallic compounds). After a certain time there is generally an abatement of the severity of the symptoms; the circulation becomes slower, the pulse small and thready, the respiration gentle, and the skin cold; syncope then supervenes, and great general insensibility, always commencing at the pelvic extremities; and sometimes convulsions occur; the secretion of urine is generally diminished, sometimes even entirely suppressed; but the patients always urinate if the sublimate has been employed in a very diluted state, and if drinks have been administered. Death often appears to result from the shock to the nervous system, from intense exhaustion, or from mortification or intense inflammation of the primæ viæ. Poisoning by corrosive sublimate is distinguished from that by arsenic, by the countenance being flushed, and even swollen; whereas, in poisoning by arsenic, it is wholly contracted and ghastly, and by the whitened condition of the epithelium of the mouth.
2. Antidotes. White of egg, hydrated ferric sulphide or ferrous sulphide, and gluten, are each of them powerful antidotes. White of egg has proved efficacious in numerous cases. It requires the white of one egg to decompose 4 gr. of corrosive sublimate. (Peschier.) The recently precipitated protosulphuret of iron is, however, according to Mialhe, the antidote par excellence, not only to corrosive sublimate, but to the salts of lead and copper. The gluten of wheat has also been recommended (Taddei); or, what is equally efficacious, wheat flour mixed up with water. When any of the above are not at hand, copious draughts of milk may be substituted. Iron filings have been occasionally used as an antidote. All these substances should be taken in considerable quantities; the dose should be frequently repeated, and the general treatment similar to that in cases of poisoning by arsenic. Vomiting should be, in all cases, immediately induced, to remove, if possible, the poisonous matter from the stomach.
Mercuric-ammonium Chloride. HgNH2Cl. Syn. Ammonio-chloride of Mercury, Ammoniated chloride of mercury, White precipitate, Lemery’s w. p., Cosmetic mercury; Hydrargyri ammoniatum (B. P.), Hydrargyri ammonio-chloridum (Ph. L.), Hydrargyrum precipitatum album (Ph. E.)
Prep. 1. (Ph. L.) Mercuric chloride, 6 oz.; distilled water, 3 quarts; dissolve, with heat, and when the solution has cooled, add of liquor of ammonia 8 fl. oz., frequently shaking it; lastly, wash the precipitate with water, and dry it. The formulæ of the Ph. E. & D. are nearly similar.