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OXALIC ACID, ITS DETECTION.

tested by the methods already described. Owing to the effect of early vomiting and treatment, it is not usual to find much oxalic acid in the contents of the stomach. From milk, gruel, coffee, blood, mucus, and other viscid liquids, oxalic acid is readily separated by the process of dialysis, as described under sulphuric acid (see p. 74, ante). The liquid should be first boiled-the coats of the stomach (cut up) being included, if necessary. The distilled water placed on the outside of the tube will receive the acid. This may be concentrated by evaporation. Prismatic crystals may thus be procured, and the silver and calcium sulphate tests may be applied.

The presence of oxalic acid in an organic liquid may be detected by another dialytic method. Place a portion of the liquid containing the poison in a beaker, and insert in this a tube secured with skin or parchment-paper containing a solution of calcium sulphate. The oxalic acid

Fig. 3.

will penetrate the membrane, and will form inside the mouth of the latter a deposit of crystals of oxalate of calcium, known by their octahedral form (Fig. 3).

Sometimes the chemical evidence may depend on stains on articles of clothing. Oxalic acid discharges the colour of some dyes, and slowly reddens others; but unless the stuff has been washed, the acid remains in the fabric, and may there be detected. It does not corrode or destroy the stuff like mineral acids. In Reg. v. Morris (C. C. C., Dec. 1866) it was proved that the prisoner had attempted to administer a liquid poison forcibly to her daughter, a girl aged six years. It was sour in taste, made her lips smart, and caused vomiting. There was dryness of the lips, and inflammation of the lining membrane of the mouth. No portion of the substance administered could be procured, but a crystalline deposit of oxalic acid was obtained from some stains on the dress of the child. The woman was convicted.

Crystals of Calcium Oxalate obtained by dialysis of Coffee containing Oxalic Acid, magnified 350 diameters.

ACID POTASSIUM OXALATE, OR SALT OF SORREL.-Symptoms and Effects. This poisonous salt is much used for the purpose of bleaching straw and removing ink-stains, and is sold for this purpose under the name of essential salts of lemons. Its poisonous properties are not generally known, or no doubt it would be frequently substituted for oxalic acid. Out of four cases of poisoning by this substance, three proved fatal, while in the other the patient recovered. In the case of recovery, a young lady, aged twenty, swallowed an ounce of the salt dissolved in warm water. She was not seen by any one for an hour

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87

and a half; she was then found on the floor, faint and exhausted, having previously vomited considerably. There was great depression, the skin cold and clammy, the pulse feeble, and there was a scalding sensation in the throat and stomach. There was also continued shivering. Proper medical treatment was adopted, and she recovered in two days, still suffering from debility and great irritation of the stomach. During the state of depression, it was remarked that the membranes of the eyes were much injected and the pupils dilated. There was also great dimness of vision. (Med. Gaz.,' vol. 27, p. 480.)

This salt destroys life almost as rapidly as oxalic acid itself; and in the symptoms which it produces, it closely resembles that poison. In one case, half an ounce killed an adult in so short a time as eight minutes; but probably the fatal effects were in this instance accelerated by the debilitated state of the person who took it. In another case death took place in ten minutes. (Ann. d'Hyg.,' 1850, vol. 1, p. 162.) In some instances this poisonous substance has been supplied by mistake for cream of tartar, and has thus caused death.

Chemical Analysis. It is not very soluble in cold water, but its solu tion may be readily mistaken for that of oxalic acid. The tests for oxalic acid may be applied for the detection of it in this salt. When a portion is heated, potassium carbonate is left.

VEGETABLE ACIDS.

The vegetable acids, such as the acetic, tartaric, and citric, are capable of acting as poisons. The editor has met with alarming laryngeal symptoms, besides the local corrosive action, produced by the swallowing of acetic acid. Bayard and Devergie have recorded a fatal case of poisoning with tartaric acid. (Ann. d'Hyg.,' xlvi. p. 433.) In 1877 a woman, æt. 58, died in Sheffield from taking a quantity of aromatic vinegar.

CHAPTER 9.

ALKALIES AND ALKALINE SALTS.-POTASH, SODA, AND AMMONIA.-NITRATE AND SULPHATE OF POTASSIUM.-SALTS OF BARIUM.

POTASH AND SODA.

Symptoms.-The symptoms produced by potash and soda, when taken in large doses, are similar, so that one description will serve for both. The most common form in which these poisons are met with is in the state of pearlash (potassium carbonate) and soap-lees (sodium carbonate). The person experiences, during the act of swallowing, an acrid caustic taste, owing to the alkaline liquid, if sufficiently concentrated, excoriating the mucous membrane. There is a persistent sensation of burning heat in the throat, extending downwards to the stomach. Vomiting is not always observed; but when it does occur, the vomited

888

ALKALINE POISONING.

AMMONIA.

matters are sometimes mixed with blood of a dark brown colour, and with detached portions or flakes of mucous membrane-this effect depending on the degree of causticity in the liquid swallowed. The surface is cold and clammy, and there is purging with severe pain in the abdomen, resembling colic. The pulse is quick and feeble. In the course of a short time, the lips, tongue, and throat become swollen, soft, and red. Other symptoms of a more serious kind sometimes show themselves. In 1877, a cook in a girls' boarding-school put four ounces of washing soda (crude carbonate) into the tea supplied to the pupils. They suffered from severe colicky pains and purging, continuing for several days, with griping pains, loss of appetite, and general feeling of weakness. One girl, æt. 16, who had partaken freely of the tea, in addition to these symptoms, suffered severely on the fifth day from purpura. There was hæmatemesis, with profuse bleeding from every mucous surface, and spots of ecchymosis on all parts of the skin. She had a tedious and very difficult recovery. It was calculated that she had taken about two drachms of soda. The most rapidly fatal case of alkaline poisoning reported is that of a boy, who died in three hours after swallowing three ounces of a strong solution of carbonate of potassium.

Appearances after Death. In recent cases there are marks of the local action of the poison on the mucous membrane of the mouth, throat, and gullet. This membrane has been found softened, detached, and inflamed in patches of a deep chocolate colour, sometimes almost black. A similar appearance has been met with in the mucous membrane of the larynx and windpipe. The stomach has had its mucous surface destroyed in patches, and there has been partial inflammation. In one instance, as the result of the action of soda, it was puckered, hardened, and blackened. The quantity of these alkaline poisons required to destroy life is unknown. The fatal effects depend rather on the degree of concentration of the liquid than on the absolute quantity of alkali present.

Chemical Analysis.-When potash or soda, or the carbonate of either alkali, is contained in a poisonous proportion in any organic liquid, it will be observed that the liquid has not only a strong alkaline reaction, but it is soapy to the feel, frothy when shaken, and has a peculiar odour. The alkali may be obtained in the state of carbonate or otherwise by simply evaporating the suspected liquid and incinerating the residue in a silver or porcelain vessel. The presence of potash or soda may be easily determined by the appropriate tests for these alkalies. Potash gives a violet, and soda an intensely yellow colour to a colourless gas-flame.

AMMONIA.

The vapour of strong ammonia is poisonous. Several severe cases have been seen by the editor. It may destroy life by producing violent inflammation of the larynx, or of the lungs and air-passages. It is often employed injudiciously to rouse persons from a fit. A case is on record of an epileptic having died under all the symptoms of

SYMPTOMS AND APPEARANCES.

89

croup, two days after the application of strong ammonia in vapour to the nostrils, in order to rouse him from a fit.

Symptoms and Appearances.-The strong solution of ammonia produces, when swallowed, symptoms similar to those described in speaking of potash, but, as it is much more irritating, it produces a choking sensation, followed by intense heat and burning pain in the throat, gullet, and stomach.

Serious injury to the organs of respiration is one of the results of the action of this poison. A man liable to attacks of fainting, died in three days after swallowing a quantity of a liquid administered to him by his son. This liquid, which was at the time believed to be sal volatile, was, in fact, a strong solution of ammonia. The deceased complained immediately of a sensation of choking and strangling in the act of vomiting. Symptoms of difficulty of breathing set in, with other signs of irritation in the throat and stomach. The mucous membrane of the mouth and throat was corroded and dissolved; and it was evident that the liquid had caused great local irritation. The difficulty of breathing was such as to threaten suffocation, and at one time it was thought that an operation must be resorted to. The state of the patient, however, precluded its performance, and he died on the third day. On inspection, the viscera presented strong marks of corrosion. The covering of the tongue was softened, and had peeled off; the lining membrane of the air-passages was softened and covered with layers of false membrane, the result of inflammation; and the larger bronchial tubes were completely obstructed by casts or cylinders of this membrane. The lining membrane of the gullet was softened, and at the lower part, near its junction with the stomach, the tube was completely dissolved and destroyed. There was an aperture in the stomach in its anterior wall, about an inch and a half in diameter: the edges were soft, ragged, and blackened, presenting an appearance of solution. The contents of the stomach bad escaped. On the inside, the vessels were injected with dark-coloured blood, and there were numerous small effusions of blood in various parts of the mucous membrane. The coats were thinned and softened at the seat of the aperture. The blackened and congested appearance of the lining membrane somewhat resembled that which is seen in poisoning with sulphuric or oxalic acid. The mucous matter on the coats of the stomach was feebly acid. No poison of any kind was found in the layer of mucus or in the coats. There was not in any part the slightest trace of ammonia, the poison which had caused the mischief. The deceased had lived three days; remedies had been used, and every trace of ammonia had disappeared. The immediate cause of death was an obstruction of the air-tubes, as a result of inflammation, caused by the local irritant action of the liquid: it was quite obvious that a quantity had entered the windpipe. The perforation of the stomach had probably taken pace shortly before death, or was, perhaps, post-mortem, as there were no marks of peritonitis. The injury to the stomach and gullet would have been sufficient to cause death, even supposing that the liquid had not penetrated into the lungs. A child, about two years old, swallowed

a teaspoonful of strong solution of ammonia. It fell to the floor breathing hurriedly, and became blue in the face. An hour afterwards, there were white patches on the tongue and cheeks, with congestion of the tonsils and pharynx. There was frequent vomiting, but no blood. Pulse, 164; temperature, 102.8° F. The child died the next day. It was unconscious, and there were convulsions at intervals. ('Med. Times and Gaz.,' 1878, i. p. 35.)

Solution of ammonia applied to the skin acts as a corrosive, and may inflame or cause the destruction of the parts which it touches. A man was convicted (Reg. v. Gavan, Stafford Sum. Ass., 1873) of throwing a liniment, containing a strong solution of ammonia, over the prosecutrix, with intent to injure her. The liquid was thrown in her face, and some portion reached the eyes; but she recovered from the effects. A weak solution acts as an irritant to the skin, while a strong solution causes vesication and a destruction of the part.

Carbonate of Ammonium.-The concentrated solution of this salt (sal volatile) is probably more active as a poison than is commonly supposed. A man, in a fit of passion, swallowed about five fluid drachms of a solution of sal volatile. In ten minutes he was seized with stupor and insensibility; but, upon the application of stimulant remedies, he recovered. He suffered for some time afterwards from severe irritation about the throat and gullet.

A female, æt. 19, while in a state of unconsciousness, was made to swallow a quantity of hartshorn. She immediately felt a severe pain in the stomach, and in about an hour afterwards she vomited some blood. This vomiting of blood continued for several days. These symptoms were followed by great irritability of the stomach, and the constant rejection of food. There was obstinate constipation of the bowels, with emaciation and loss of strength. She died in about three months from the time at which she had swallowed the alkaline poison. On inspection, the gullet was found healthy; but the orifice, at its junction with the stomach, was slightly contracted. The intestinal opening (pylorus) was contracted to the size of a crow-quill, and the coats were thickened. On the posterior wall of the stomach there was a dense cicatrix of the size of a half-crown, and from this point fibrous bands ramified in various directions. The duodenum and other parts of the intestinal canal were healthy. (Med. Times and Gaz.,' 1853, ii. p. 554.)

Chemical Analysis.-Ammonia is distinguished from potash and soda by its pungent odour and entire volatility. The Carbonate of Ammonium may be known from other salts by its alkaline reaction, its odour, and its volatility as a solid; and from pure ammonia by its effervescing on the addition of an acid.

NITRATE OF POTASSIUM. NITRE. SALTPETRE.

Symptoms and Appearances.-This well-known salt has on several occasions destroyed life when taken in large doses. A man swallowed an ounce of nitre, mixed with water, by mistake for Epsom salts, about nine o'clock in the morning. It produced vomiting with severe pain,