Memoranda on Poisons Part 7

CORROSIVE SUBLIMATE (_Oxymuriate of Mercury_, _Chloride of Mercury_, _Bichloride of Mercury_).-This preparation of Mercury, which, more strictly speaking, belongs, like the chlorides of zinc and antimony, to the cla.s.s Corrosives, is usually met with in the form of imperfect crystalline ma.s.ses, or as a white powder. It has an acrid, coppery taste, so powerful that but little could be swallowed without the individual becoming aware of it. It is very soluble in water. Three grains is the smallest quant.i.ty that has been known to prove fatal; and from this to five grains may probably be stated as the average dose necessary to destroy life. Recovery has taken place after as much as eighty grains had been swallowed. Death has occurred in less than half an hour; while, in some instances, life has been maintained until the sixth day, and in one instance (where between three and four scruples had been swallowed) until the twelfth day. It is probable that the average duration of fatal cases is from twenty-four to thirty-six hours.

_Symptoms._-In the majority of cases the symptoms commence immediately, with an acrid metallic taste, often described as coppery, and a sense of constriction and burning heat in the throat and stomach. The burning pain gradually extends over the abdomen, and is much increased by pressure. There is nausea, with vomiting of the contents of the stomach.

These matters are sometimes mixed with blood and stringy ma.s.ses of mucus. The sickness is accompanied by diarrha or dysentery, swelling of the abdomen, and increased pain. The countenance becomes flushed and often swollen, though it is occasionally pallid and anxious; the lips and tongue get white and shrivelled; there is frequently some dyspna, while the pulse is small, or wiry and frequent; and death is preceded by faintness, cramps, insensibility, or convulsions.

Should these effects not prove rapidly fatal, the pain will gradually become lessened, though attacks of colic and nausea may come on at intervals for several days. Often the secretion of urine is almost, or even quite, suppressed. After a time there are symptoms of hectic fever, with much depression. The gums and salivary glands also become swollen, there is a coppery taste in the mouth, the breath is very ftid, and there is severe ptyalism or salivation. This latter effect is the most prominent feature in the _chronic_ form of poisoning, where small and frequently-repeated doses have been given: it often proceeds to such an extent as to cause death, when the patient would otherwise probably recover.

It must not be forgotten that salivation sometimes arises where no mercurial of any kind has been given. Thus a.r.s.enic, bis.m.u.th, lead, iodide of pota.s.sium, opium, &c., may induce it in some very peculiar const.i.tutions. Small medicinal doses (as a few grains of calomel) may also excite it in certain susceptible individuals; and especially in persons suffering from renal disease. It may also occur spontaneously, as in stomat.i.tis or inflammation of the mouth; and very troublesome examples of it may occur in pregnant women.

It is strange that neither in acute nor chronic mercurial poisoning do we observe any marked loss of muscular power. Yet workers in quicksilver (owing to the absorption of the fumes of mercury during respiration) are very apt to suffer from a peculiar kind of paralysis; which commences with inability to direct the hands and arms, and goes on to a shaking or trembling of all parts of the body.

_Post-mortem Appearances._-The appearances produced by corrosive sublimate are confined chiefly to the digestive ca.n.a.l. The mucous membrane of the mouth, fauces, and sophagus is softened and of a whitish or bluish-grey color. The stomach also presents marks of violent inflammation; beneath the mucous membrane numerous patches of extravasated blood are seen, and frequently corrosion or ulceration has been found. The large and small intestines, the peritoneum, and especially the urinary organs, often appear inflamed. In many instances the bladder has been much contracted.

_Treatment._-This must consist in the removal of the poison and the administration of antidotes. Vomiting is best promoted by administering copious draughts of fluids containing alb.u.men: but if necessary ipecacuan may be given. The white and the yolk of raw eggs with milk should be abundantly administered. Gluten has been much recommended, and may readily be prepared by washing flour in a muslin bag under a stream of water; but on an emergency it will be best to exhibit the flour at once, made into a paste with milk or water. The free use of demulcent drinks, milk, and ice will be very grateful to the patient's feelings.

Gargles of alum or borax do some good. Opiates may be given in small doses, if there be much pain, and we should allow only a milk or farinaceous diet. Sucking chlorate of potash has been recommended to check the salivation. The most useful remedy, however, is the iodide of pota.s.sium; for this salt destroys the compounds formed by the union of mercury with certain of the tissues, and eliminates the poison through the kidneys.

_Tests._-Corrosive sublimate is completely volatilized by heat.

1. Liquor pota.s.sae added to its solution gives a yellow precipitate. This precipitate, if washed, dried, and heated in a test tube, gives a ring of metallic mercury in the form of globules in the cool part of the tube. In like fashion corrosive sublimate itself may be reduced and volatilized if heated with black flux.

2. On adding a solution of iodide of pota.s.sium to a small quant.i.ty of the solution, a bright scarlet precipitate, soluble in excess of iodide of pota.s.sium, is produced.

3. If a drop or two of a solution of corrosive sublimate, slightly acidulated with hydrochloric acid, be placed on a sovereign, and the solution and the gold be touched with a piece of zinc or an iron key, the mercury will be deposited as a bright silvery stain on the gold.

CALOMEL (_Subchloride_ or _Chloride of Mercury_) is a heavy white powder, which is usually regarded as a safe medicine. Yet, in some peculiar const.i.tutions, it has caused excessive salivation and death, even though only a few grains have been given. In large doses it may be regarded as an irritant poison. It is distinguished from corrosive sublimate by forming a black precipitate with caustic potash and by its insolubility in water.

AMMONIO CHLORIDE OF MERCURY (_White Precipitate_).-This substance is a chalky looking powder, containing about eighty per cent. of mercury. It produces vomiting, purging, great pain in the stomach, cramps, and convulsions. Out of fourteen cases, collected by Dr. Taylor, in which from a few to forty grains were taken, only two proved fatal.

The remaining preparations of mercury, which in rare instances have been used as poisons, are the _Red Oxide of Mercury_ (red precipitate); the _Red Sulphuret of Mercury_ (cinnabar or vermilion); the _Cyanide of Mercury_; the _Nitrates of Mercury_; and _Turpeth Mineral_.

Mercury may be separated from organic admixture by Reinsch's method.

CHAPTER XVIII.

PREPARATIONS OF LEAD.

Lead, in its metallic state, is not injurious. It is, however, really acted on by acids, exposure to the atmosphere, &c., and converted into carbonate of lead. The chief compounds of this metal which have been found to produce poisonous effects are the acetate, subacetate, and the carbonate.

ACETATE OF LEAD (_Sugar of Lead_).-This is sold as a glistening white powder, or in the form of crystalline ma.s.ses resembling loaf sugar. It is more frequently used as a poison than either of the other compounds.

It is very soluble in water and has a sweetish metallic taste. Three or four instances are recorded in which recovery has taken place after an ounce of this substance has been taken in solution.

Mr. Bancks, of Stourbridge, has reported the particulars of a series of cases of poisoning by the acetate of lead (_Lancet_, 5th May, 1849). It appears that thirty pounds of this substance were accidentally mixed at the miller's with eighty sacks of flour. This was made into bread, from eating which 500 persons suffered severely. The chief symptoms were a sense of constriction in the throat and at the pit of the stomach, crampy pains round the navel, stiffness of the abdominal muscles, paralysis of the lower extremities, constipation, scanty urine, and the formation of a deep blue line round the gums. Although in many cases there was great prostration with other alarming symptoms, yet under the use of purgatives all recovered. It was noticed that after a temporary convalescence many of the symptoms returned in an aggravated form without any apparent cause. Sometimes there has been vomiting and purging, and there is great prostration, with cramps and convulsions.

_Post-mortem Appearances._-They are not usually very distinct. The stomach and intestines have been found inflamed, and the surface of the former softened and, in the case of animals, corroded. There may be no characteristic signs in chronic poisoning.

SUBACETATE OF LEAD (_Goulard's Extract_).-This substance is known to have proved fatal in three or four instances, after having caused great agony. It is a more powerful poison than the acetate. It is found in the shops as a whitish-colored liquid.

CARBONATE OF LEAD (_White Lead_, _Ceruse_, _&c._).-This is sold in heavy white ma.s.ses, looking like chalk. It is readily acted on by acids, but is very insoluble in water.

Dr. Snow has reported an instance in which a child ate a portion, about the size of a marble, mixed up with oil; it died on the fourth day.

Carbonate of lead derives its greatest interest from the chronic form of poisoning which it produces among white lead manufacturers, painters, &c., known as "the painters' colic," which too often terminates in "lead palsy." In these instances the lead finds its way into the system by absorption from the digestive ca.n.a.l, the lungs, or the skin; producing its characteristic effects when a sufficient amount has been absorbed.

It is this salt which is formed by the action of air and water upon lead.

The other preparations of this metal do not require any separate notice.

_Treatment._-The sulphates of soda or magnesia should be freely given dissolved in water. Milk, or milk and eggs will be useful. If vomiting is absent, an emetic of sulphate of zinc should be administered, or the stomach-pump may be advantageously employed.

For a chemical antidote in poisoning by carbonate of lead Dr. Taylor recommends a mixture of vinegar and sulphate of magnesia.

_Tests._-The presence of a salt of lead in solution may be thus ascertained:-1. On pa.s.sing sulphuretted hydrogen through it, or on adding a few drops of sulphide of ammonium, a black precipitate is given. 2. A white precipitate results from the use of liquor pota.s.sae or liquor ammoniae. 3. Dilute sulphuric acid gives a similar precipitate, which is insoluble in nitric acid. 4. Iodide of pota.s.sium affords a bright yellow deposit (iodide of lead).

CHRONIC LEAD POISONING.-The chronic and insidious effects produced by lead upon the const.i.tution are deserving of careful attention. Water impregnated with this metal in its pa.s.sage through lead pipes or cisterns, acquires poisonous properties. Lead-pigments are sometimes improperly used to color cheese, lozenges, snuff, &c. The endemic colic of Devonshire was due to the absorption of lead contained in cider, which had been made in leaden vessels; and in the wine district of Poictou attacks of colic were so common, from the impregnation of wine with this metal, that we still speak of "colica Pictonum."

The pernicious influence of lead is manifested among those engaged in the manufacture or use of lead compounds, especially painters, lead smelters, plumbers, color grinders, shot manufacturers, workers in sugar of lead, potters, compositors, enamellers of cards, &c. These artisans should be advised to prevent disease by great cleanliness, by avoiding intoxicating liquors, and by drinking freely of sulphuric acid lemonade.

The subst.i.tution of moist for dry grinding has proved useful.

The most prominent _symptoms_ of chronic poisoning by lead are as follows: A blue line around the gums, and the liability of the latter to bleed from any slight cause; emaciation, a pallid tint of the complexion, poorness of blood, and a feeble quick pulse; obstinate constipation, with attacks of colic relieved by pressure; diminution of the renal secretion and rheumatic pains; afterwards comes weakness of the hands, wrists, and arms, ending in paralysis of the extensors, or "dropped wrists," creeping up the arms.

The _treatment_ of these cases must consist in the first instance in the use of purgatives; none being better than sulphate of magnesia with the dilute sulphuric acid. But the remedy of all others is the iodide of pota.s.sium, in five or ten grain doses thrice daily; this agent acting most beneficially when employed in conjunction with galvanism to the paralysed limbs.

CHAPTER XIX.

SALTS OF COPPER.

Poisoning with the salts of copper is of comparatively rare occurrence; when it happens, it is generally the result of accident. The metal itself is not poisonous, but the action of the gastric juice may produce a very deleterious salt. Copper coins, when swallowed, sometimes on this account prove mischievous; though usually any ill effects which ensue are due to their mechanical action. Salts of copper have been accidentally introduced into the system by means of food which has been cooked in copper saucers. The most important substances of this cla.s.s to the toxicologist are the following:

SULPHATE OF COPPER (_Blue Vitriol_).-Blue-stone is met with in large crystals, which are very soluble in water and possess an acrid metallic taste. In doses of half an ounce it acts as a powerful irritant. It has been administered to procure abortion. In the case of a child sixteen months old, who sucked some pieces of blue-stone with which she was playing, death occurred in four hours.

SUBACETATE OF COPPER (_Verdigris_).-This preparation is met with in ma.s.ses, or in the form of a greenish powder. It possesses a powerful astringent metallic taste. It is often produced by allowing substances to stand in coppers. It has proved fatal in half ounce doses.

a.r.s.eNITE OF COPPER (_Mineral Green_).-The effects of this salt have been already referred to.

_Symptoms._-Pain in the epigastrium, gradually extending over the abdomen, violent vomiting-the vomited matters being of a blue or green color-and diarrha, are the symptoms which set in the most speedily.

Then there is usually dyspna, great depression, coldness of the extremities, headache with giddiness, and slight tetanic convulsions.

Sometimes there is suppression of urine. Jaundice very frequently occurs-a symptom the more important, as it is rarely met with in most other forms of poisoning. Occasionally stupor, coma, and paralysis supervene. Should death ensue, it may occur within a few hours, or not for several days.

The salts of copper taken in very small doses, for several days, give rise to a metallic taste in the mouth, thirst, debility, cramps and colicky pains, with symptoms of dysentery. In some instances there has been found retraction of the gums with the formation of a purple line, very distinct from the blue mark due to lead.

_Post-mortem Appearances._-Evidences of inflammation are usually found in the stomach and intestines, the mucous membrane being often ulcerated and of a blue-green color. Particles of the poison may sometimes be found adhering to the coats of the bowel. Perforation of the intestines has occurred.

_Treatment._-Vomiting sets in spontaneously, and is to be encouraged by the use of warm water. The stomach pump will rarely be needed. The only effectual antidote is alb.u.men. The whites and yolks of several eggs should therefore be given, followed immediately by milk or mucilaginous drinks.