Section III.—Of the Morbid Appearances caused by Lead.
The morbid appearances caused by poisoning with lead are in some respects peculiar.
In acute poisoning, from the irritant action of its soluble salts, as in the case of the drummer poisoned by Goulard’s extract, the lower end of the gullet, the whole stomach and duodenum, part of the jejunum, and the ascending and transverse colon, have been found much inflamed, and the villous coat of the stomach as if macerated. In Mr. Taylor’s two cases Dr. Bird found the villous coat of the stomach gray, but otherwise natural; and the intestines were much contracted.
The stomach in the first of these cases contained a reddish-brown, sweetish, styptic fluid, in which lead was detected by chemical analysis,[[1354]]—an important medico-legal fact, since the man survived nearly three days. Some valuable observations have been made by Professor Orfila as to the presence of lead in the textures of the stomach in such instances. When small doses of acetate or nitrate of lead were administered to dogs and allowed to act for two hours only, the villous coat presented numerous streaks of white points, which contained lead, as hydrosulphuric acid blackened them. These points, though less distinct, were still visible, when the animals were allowed to live four days after the excess of salt had been removed; and even after seventeen days, although no such appearance remained, lead could still be detected in the tissues of the stomach.[[1355]]
The blood in animals is sometimes altered. Dr. Campbell found it fluid. In a dog poisoned with litharge, the experimentalists of the Veterinary School at Lyons found it of a vermilion colour in the veins, and brighter than usual in the arteries.[[1356]] Mitscherlich also found it unusually red and firmly coagulated.[[1357]]
The appearances in the bodies of those who have died of the various forms of lead colic are different, and wholly unconnected with inflammation.
The valuable work of Mérat contains four inspections after death from the acute or comatose form of colica pictonum. The bodies were plump, muscular and fat. The alimentary canal was quite empty, and the colon much contracted,—in one to an extraordinary degree. The mucous coat of the alimentary canal was everywhere healthy. He therefore infers that the disease is an affection of the muscular coat only. It is a striking circumstance, and conformable with what will be afterwards established in regard to the true narcotics, that although both of the men died convulsed and comatose, no morbid appearance was visible within the head.[[1358]] Another case, which confirms the foregoing facts, has been described by Mr. Deering. It was that of a lady who died convulsed after suffering in the usual manner, and in whose body no trace of disease could be detected any where.[[1359]] Senac informed Tronchin that he had dissected above fifty cases of colica pictonum, and found no morbid appearances.[[1360]] Schloepfer’s observations on animals are to the same effect. In rabbits which died of colica pictonum the great intestines were excessively contracted, but all the other organs of the body were healthy except the liver, which was dark and brittle.[[1361]] Mitscherlich observed in his animals extravasation of blood into the intestines, also sometimes into the cavities of the pleura and peritoneum, and occasionally under the peritoneal covering of the kidneys.[[1362]] The only instance I have met with where morbid appearances were found within the head, was in a case mentioned by Sir G. Baker, of a gentleman who died apoplectic after many attacks of colica pictonum, and in whom the brain was found unusually soft, and blood extravasated on its surface to the amount of an ounce.[[1363]]
The appearances in those who have been long affected with the paralytic form of colica pictonum have been rarely observed in modern times. I am indebted to my late colleague, Dr. Duncan, Junior, for an account of the appearances in the intestinal canal of a plumber, who had been long and frequently afflicted with colica pictonum and its sequelæ. The intestines were dark, tender, and far advanced in putrefaction. The cardiac orifice of the stomach was so narrow that it would admit a goose-quill. The mesenteric glands were enlarged and hardened. The thoracic duct was surrounded by many large bodies like diseased glands, exactly of the colour of lead, and composed of organized cysts containing apparently an inorganic matter. The analysis of this matter was unfortunately neglected. The muscles in similar circumstances are much diseased. When the paralysis is not of long standing, it appears from the experiments of Schloepfer (whose animals survived about three weeks), that the whole muscular system becomes pale, bloodless, and flaccid. When the palsy is of long standing, this change increases so much, that the muscles in some parts, as in the arms and thumbs, acquire the colour and general aspect of white fibrous tissue. Some observations on the nature of these changes will be found in the essays of Sir G. Baker.[[1364]] The facts are communicated by Mr. John Hunter. On examining the muscles of the arm and hand of a house-painter who was killed by an accident, Mr. Hunter found them all of a cream colour, and very opaque, their fibres distinct, and their texture unusually dry and tough. These alterations he at first imagined might have been the result merely of the palsy and consequent inactivity of the muscles, but on finding the same alterations produced by the direct action of sugar of lead on muscle, he inferred that the poison gradually effected a change either on the muscles directly, or on the blood which supplied them.
In a late elaborate inquiry into the pathology of lead-colic, M. Tanquerel has arrived at the conclusion, that “the pathological phenomena are not caused by anatomical changes cognisable by the senses,” and that such appearances as may be found are the effects, not the cause, of the disease.[[1365]]