Part 7 (2/2)

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 Devons.h.i.+re 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.

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