at length begin to operate suddenly. The symptoms which it then occasions are sometimes those of irritation; namely incessant vomiting and purging, acute pain in the stomach, loaded tongue, rapid and extreme emaciation, violent cramps and small frequent pulse. These symptoms may continue many days, and even when subdued to a certain extent, vomiting and cramps are apt to recur for months after *. A fatal case of this form of affection has been related by M. Zink, a Swiss physician. His patient, after taking too large doses of iodine for about a month, was seized with restlessness, burning heat of skin, tremors, palpitation, syncope, excessive thirst, a sense of burning along the gullet, frequent purging of bilious and black stools, priapism, tremulous pulse. The symptoms of local inflammation went off in a few days; but those of general fever continued; and he died after six weeks' illness +. Another fatal case has been described in Rust's Journal. The leading symptoms were pain in the region of the liver, loss of appetite, emaciation, quartan fever, diarrhoea, excessive weakness, and after the emaciation was far advanced a hardened liver could be felt. The patient appears to have died of exhaustion. From this case, and another of which the appearances after death will be presently noticed, it is not improbable that iodine possesses the power of inflaming the liver. In another and more common affection, the patient is attacked with tremors, at first slight and confined to the fingers, afterwards violent and extending to the whole muscles of the arms and even of the trunk. At the same time there is excessive and rapidly increasing weakness, a sense of anxiety, sinking and faintness, a total suspension of the function of digestion, rapid and extreme muscular emaciation, tendency to fainting, and violent continued palpitation §, accompanied not unfrequently with absorption of the mammæ if the patient is a female. In the midst of these phenomena the curative powers of the poison over the disease for which it has chiefly been used, namely goître, are developed. It has been remarked in particular, that the diminution of the goître keeps pace with Gairdner on the effects of Iodine, p. 9. Journal Complémentaire, xviii. 126. Magazin fur die gesammte Heilkunde, xvi. 111. § Gairdner, &c. p. 12. the diminution of the breasts, though at times either effect has been developed without the other. An instance is related in Rust's Journal of a female, whose breasts, after she had used iodine for four months, began to sink, and in four weeks hardly a vestige of them remained, while her goître was not affect ed *. The doses required to produce these effects are very various. Some people appear almost insensible to its action; in one instance, nine hundred and fifty-three grains were taken in daily portions varying from two to eighteen grains, without any bad effect; and Magendie once swallowed a scruple in the form of tincture without suffering any inconvenience. On the other hand, Dr Gairdner has seen severe symptoms commence when no more than half a grain was taken three times a day for a single week §; and Coindet has seen bad effects from thirty drops of the solution of ioduretted hydriodate taken daily for five days T. + The only account I have seen of the appearances left in the body after death from slow poisoning with iodine is contained in the essay of Dr Zinc. In a second fatal case which came under his notice, he found enlarged abdomen from distension of the intestines with gases, enlargement of the other viscera and serous effusion into the peritoneum; adhesion of the viscera to one another; redness of the intestines, in some places approaching to gangrenous discoloration; redness and excoriation of the peritoneal coat of the stomach, and also of its villous coat; enlargement and pale rose-red coloration of the liver. In the chest serum was found in the sac of the pleura. The gullet was contracted in diameter and red internally. To these remarks on Iodine, a few observations may be added on the Hydriodate of Potass, one of its compounds, which in medicine is now very generally substituted for the simple substance. The tests and action of this poison have been of late very carefully determined by M. Devergie, a French physiologist. It is generally sold in irregular crystals tending to the cubical • Magazin fur die gesammte Heilkunde, xxii. 291. Johnson's preface to his Translation of Coindet on Iodine, p. ix. Formulaire pour les Nouveaux Medicamens, 161. § Gairdner, p. 20. Coindet on Iodine, p. 17. form, having the peculiar odour of iodine, which is more distinct when they are dissolved in water. It is easily known by the effect of strong sulphuric acid, which turns it brown with effervescence, and, if heat is also applied, with the disengagement of the violet fumes of iodine. In solution its best tests are sulphuric acid, corrosive sublimate, acetate of lead, and protonitrate of mercury. Sulphuric acid disengages the iodine, forming an orange-coloured solution. Corrosive sublimate forms a fine carmine red precipitate, the iodide of mercury. Acetate of lead forms a fine yellow precipitate, the iodide of lead. Protonitrate of mercury throws down a carmine red precipitate, the iodide of mercury. The corrosive sublimate is delicate enough to detect the hydriodate in 2000 parts of water; the sulphuric acid in 10,000 parts; acetate of lead in 18,000; and the nitrate of mercury in 60,000. Few of the ordinary organic fluids alter the action of the tests, unless they are much coloured. In that case the best plan is to evaporate to dryness and char the residue by raising the heat. The salt is not decomposed, and may be dissolved out by pure water, after which it may be subjected to its usual tests. From the experiments of Devergie on animals, it seems to be in large doses an irritant, though not a powerful one. Two drachms in an ounce of water killed a dog in three days with violent vomiting, and signs of irritation were found in the stomach, namely black extravasation and ulcers in the middle of them. A solution injected into the cellular tissue caused only local inflammation. Injected into the jugular vein in the dose of four grains, it caused tetanus and death in a minute and a-half *. I am not acquainted with any case of poisoning with this substance in the human subject. It is believed to have the same power as iodine over goître, and not to be so apt to injure the stomach and constitution. • Archives Générales de Médecine, x. 255. CHAPTER V. OF POISONING WITH OXALIC ACID. THE last poison of this order is Oxalic Acid. It is a substance of very great interest, for of late years it has caused death in our own country more frequently perhaps than any other variety of poisoning. It was first introduced to the notice of the physician as a poison by Mr Royston in 1814*, in consequence of its having been taken by mistake for Epsom salt;—a mistake which has apparently become more frequent since people were put on their guard against it. Now that its properties are familiarly known, it is often resorted to for committing suicide, for which purpose, indeed, the certainty and rapidity of its operation render it superior to all ordinary poisons. It is certainly ill adapted for the purposes of the murderer; for although it might be easily given to a sick person instead of a laxative salt, yet its real nature would betray itself too soon and too unequivocally for the chief object of the prisoner,-secresy. Nevertheless, at least one attempt of the kind has been made. At the trial of James Brown for assaulting his wife, held at the Middlesex Autumn Assizes 1827, it was brought out in evidence that he had previously tried to poison her by giving her oxalic acid in gin†. Its properties have been examined by Dr A. T. Thomson of London, and Dr Perey of Lausanne §; and in 1823, the whole subject of poisoning with oxalic acid in its medico-legal relations was examined by Dr Coindet of Geneva and myself. SECTION I-Of the Tests for Oxalic Acid. Oxalic acid is commonly in small crystals of the form of flattened six-sided prisms, transparent, colourless, free of odour, London Medical Repository, i. 382. + London Courier, September 22, 1827. London Medical Repository, iii. 382. § Dissertatio Inauguralis de Acidi Oxalici vi venenata, Edin. 1821. Edin. Med. and Surg. Journal. xix. 163. very acid to the taste, and permanent in the air. Two other common vegetable acids, the citric and tartaric acids, differ from the oxalic in being seldom regularly crystallized and never in fine prisms. In general appearance it closely resembles the sulphate of magnesia, for which it has been so often and so fatally mistaken. So close, indeed, is the resemblance, that repeatedly, on desiring several persons to point out which was the poison and which the laxative, I have found as many fix on the wrong as on the right parcel. The sulphate of magnesia has of course a very different taste, being strongly bitter. Various plans have been devised for preventing the accident to which this unlucky resemblance has given rise. The best of them imply the use of a criterion or safeguard by the patient before he takes his laxative draught. It seems to have escaped the notice of those who have proposed the plans in question, that, if accidents are to be prevented in this manner, by far the simplest and most effectual security will be to let the public know that a laxative salt ought always to be tasted before it is swallowed. Its solubility has been much overrated by chemists. Thenard and others say it is soluble in twice its weight of temperate water; but it does not appear to me soluble in less than eleven parts. In determining the medico-legal tests for oxalic acid, it will be sufficient to consider it in two states,-dissolved in water,and mixed with the contents of the stomach and intestines or vomited matter. If the substance submitted to examination is in the solid state, the first step is to convert it into a solution. 1. In the form of a pure solution, its nature may be satisfactorily determined by the following process. The acidity of the fluid is first to be established by its effect on litmus paper. This being done the reagents might be applied at once. But it is better to neutralize the acid previously with any alkali; for then they act with greater delicacy. The remainder of the process consequently applies not only to oxalic acid itself, but also to all the soluble oxalates, which will presently be proved to be likewise active poisons.-The tests are the hydrochlorate of lime, sulphate of copper, and nitrate of sil ver. Hydrochlorate of lime causes a white precipitate, the oxalate |
