Читать книгу Treatise on Poisons - Robert Sir Christison - Страница 26

It was formerly observed that the action of the strong mineral acids is independent of the function of absorption. They act by the conveyance along the nerves of an impression produced by the irritation or destruction of the part to which they are applied. There is very little difference between the three acids in the symptoms they excite or the action they exert.

When sulphuric acid is introduced directly into a vein it causes death by coagulating the blood. Thus, when Professor Orfila injected in the jugular vein of a dog half a drachm diluted with an equal weight of water, he observed that the animal at once struggled violently, stretched out its limbs, and expired; and on opening the chest immediately, he found the heart and great vessels filled with coagulated blood.^[242]—Nitric acid and hydrochloric acid act in the same way.

If, on the other hand, they are introduced into the stomach, the blood as usual remains fluid for some time after death; the symptoms are referrible almost solely to the abdomen; and in the dead body the stomach is found extensively disorganised, and the other abdominal viscera sometimes inflamed. If the dose be large, and the animal fasting, death may take place in so short a time as three hours: but in general it lives much longer.^[243]

When the strong mineral acids are applied outwardly, they irritate, inflame, or corrode the skin. The most rapid in producing these effects is the nitric, or rather the nitrous acid. The strong, fuming nitrous acid even causes effervescence when dropped on the skin.

Orfila has proved that sulphuric acid, as well as the two other mineral acids, is absorbed; for they may be detected in the urine, when they are introduced either into the stomach or through a wound.^[244] He could not succeed, however, in detecting any of them in the liver or spleen; in which organs it will be seen, hereafter, that various other poisons may be discovered by chemical analysis. But Mr. Scoffern seems to have found sulphuric acid in the kidney, even although the individual survived the taking of the poison nearly two days.^[245] It is also worthy of remark, that, as will be proved presently, these acids may pass through the coats of the stomach by transudation, and so be found on the surface of the other organs in the belly.

Toxicology is indebted to M. Tartra for the first methodic information published respecting the symptoms caused in man by sulphuric acid and the other mineral acids:^[246] but many important additional facts have been made known by numberless cases of poisoning which have since appeared, chiefly in the periodic journals.

The symptoms caused by all the three acids are so nearly the same, that after a detailed account of those occasioned by sulphuric acid, it will not be necessary to add much on the subject under the head of nitric and muriatic acid.

M. Tartra considers that four varieties may be observed in the effects of the mineral acids. 1. Speedy death from violent corrosion and inflammation; 2. Slow death from a peculiar organic disease of the stomach and intestines; 3. Imperfect recovery, the person remaining liable ever after to irritability of the stomach; 4. Perfect recovery.

1. The most ordinary symptoms are those of the first variety,—namely, all the symptoms that characterise the most violent gastritis, accompanied likewise with burning in the throat, which is increased by pressure, swallowing, or coughing;^[247]—eructations proceeding from the gases evolved in the stomach by its chemical decomposition;—and an excruciating pain in the stomach, such as no natural inflammation can excite. The lips are commonly shrivelled, at first whitish, but afterwards brownish in the case of sulphuric acid. Occasionally there are also excoriations, more rarely little blisters. Similar marks appear on other parts of the skin with which the acid may have come in contact, such as the cheeks, neck, breast, or fingers; and these marks undergo the same change of colour as the marks on the lips. I had an opportunity of witnessing this in the case of the man who was disfigured by the Macmillans (p. 122) with sulphuric acid. He was cruelly burnt on the face as well as on the hands, which he had raised to protect his face; and the marks were at first white, but in sixteen hours became brownish. The inside of the mouth is also generally shrivelled, white, and often more or less corroded; and as the poisoning advances, the teeth become loose and yellowish-brown about the coronæ. The teeth sometimes become brown in so short a time as three hours.^[248] Occasionally the tongue, gums, and inside of the cheeks are white, and as it were polished, like ivory.^[249] There is almost always great difficulty, and sometimes complete impossibility, of swallowing. In the case of a child related by Dr. Sinclair, of Manchester, fluids taken by the mouth were returned by the nose; and the reason was obvious after death; for even then the pharynx was so much contracted as to admit a probe with difficulty.^[250] On the same account substances taken by the mouth have been discharged by an opening in the larynx which had been made to relieve impending suffocation. The matter vomited, if no fluids be swallowed, is generally brownish or black, and at first causes effervescence, if it falls on a pavement containing any lime. Afterwards this matter is mixed with shreds of membrane, which resemble the coats of the stomach, and sometimes actually consists of the disorganised coats, but are generally nothing more than coagulated mucus. The bowels are obstinately costive, the urine scanty or suppressed; and the patient is frequently harassed by distressing tenesmus and desire to pass water. The pulse all along is very weak, sometimes intermitting, and towards the close imperceptible. It is not always frequent; on the contrary, it has been observed of natural frequency, small and feeble in a patient who survived fifteen days.^[251] The countenance becomes at an early period glazed and ghastly, and the extremities cold and clammy. The breathing is often laborious, owing to the movements of the chest increasing the pain in the stomach,—or because pulmonary inflammation is also at times present,—or because the admission of air into the lungs is impeded by the injury done to the epiglottis and entrance of the larynx. To these symptoms are added occasional fits of suffocation from shreds of thick mucus sticking in the throat, and sometimes croupy respiration, with sense of impending choking.

Such is the ordinary train of symptoms in cases of the first variety. But sometimes, especially when a large dose has been swallowed, instead of these excruciating tortures, there is a deceitful tranquillity and absence of all uneasiness. Thus, in the case of a woman who was poisoned by her companions making her swallow while intoxicated aqua-fortis mixed with wine, although she had at first a good deal of pain and vomiting, there were subsequently none of the usual violent symptoms; and she died within twenty hours, complaining chiefly of tenesmus and excessive debility.^[252] Occasionally eruptions break out over the body:^[253] but their nature has not been described.

Death is seldom owing to the mere local mischief, more generally to sympathy of the circulation and nervous system with that injury. According to Bouchardat death arises from the acid entering the blood in sufficient quantity to cause coagulation.^[254] But although this certainly happens sometimes to the blood in the vessels of the stomach and adjacent organs, as will be proved under the head of the morbid appearances, there is no evidence that the same takes place throughout the blood-vessels generally, or in the great veins and heart in particular. Bouchardat’s proofs of the detection of sulphuric acid in the blood are not satisfactory.

The duration of this variety of poisoning with the acids is commonly between twelve hours and three days. But sometimes life is prolonged for a week^[255] or a fortnight;^[256] and sometimes too death takes place in a very few hours. The shortest duration among the numerous cases of adults mentioned by Tartra is six hours;^[257] but Dr. Sinclair, of Manchester, has related a case which lasted only four hours and a half;^[258] a man lately died in the Edinburgh Infirmary within four hours; and Professor Remer of Breslau once met with a case fatal in two hours.^[259]

The quantity required to produce these effects has not been ascertained, and must be liable to the same uncertainty here as in other kinds of poisoning. The smallest fatal dose of sulphuric acid I have hitherto found recorded was one drachm. It was taken with sugar by mistake for stomachic drops by a stout young man, and killed him in seven days.^[260] An infant of twelve months has been killed in twenty-four hours by half a tea-spoonful, or about thirty minims.^[261] A man has recovered after taking six drachms.^[262]

2. The second variety of symptoms belong to a peculiar modification of disease, which is described by Tartra in rather strong language. It begins with the symptoms already noticed; but these gradually abate. The patient then becomes affected with general fever, dry skin, spasms and pains of the limbs, difficult breathing, tension of the belly, salivation, and occasional vomiting, particularly of food and drink. Afterwards membranous flakes are discharged by vomiting, and the salivation is accompanied with fœtor. These flakes are often very like the mucous membrane of the stomach and intestines; and such they have often been described to be. More probably, however, they are of adventitious formation; for the mere mucous coat of the alimentary canal cannot supply the vast quantity that is evacuated. There is no doubt, however, that the lining membrane of the alimentary canal is occasionally discharged. Dr. Wilson has mentioned an instance of the ejection by coughing of about nine inches of the cylindrical lining of the pharynx and gullet six days after sulphuric acid was taken.^[263] Sometimes worms are discharged dead, and evidently corroded by the poison.^[264] Digestion is at the same time deranged, the whole functions of the body are languid, and the patient falls into a state of marasmus, which reduces him to a mere skeleton, and in the end brings him to the grave. Death may take place in a fortnight, or not for months. In one of Tartra’s cases the patient lived eight months. The vomiting of membranous flakes continues to the last.

3. The third variety includes cases of imperfect recovery. These are characterized by nothing but the greater mildness of the primary symptoms, and by the patient continuing for life liable to attacks of pain in the stomach, vomiting of food and general disorder of the digestive function.