NITRIC ACID-APPEARANCES AFTER DEATH.

99

there was a difficulty of breathing, with increase of the cough. There was a sense of tightness at the lower part of the throat, and the pulse was ard. At times he said he could scarcely breathe. He died eleven hours atter the accident. On inspection there was congestion of the windpipe and bronchial tubes, with effusion of blood in the latter. The heart was farid, and contained but little blood; and the lining membrane of the heart and aorta was inflamed. The blood gave a slightly acid reaction to text-paper. The windpipe was not examined. It is very probable the seat of mischief was in this organ, and that the deceased died from inmmatory effusion, and swelling of the parts about the opening of the w.adpipe. (Lancet, 1854, i. p. 430.) A similar accident occurred to Mr. Stewart and one of the janitors of an educational institution in Edinurgh, in 1863. They both died from the effects of the acid vapor. Chem. News, 1863, p. 132.) On Sept. 23, 1890, during attempts to extinguish a fire at some chemical stores, a bottle of nitric acid was broken. The action of the acid upon surrounding articles gave rise to abundant evolution of nitrous fumes, and two of the fire-brigade officers were so affected by their inhalation that they died the same day. (Pharm. Jour., 1890-1, p. 252.)

The fumes from batteries charged with nitric acid are often productive of serious results; and the editor has met with alarming illness arising from the inhalation of the nitrous fumes given off during the working of such batteries in an ill-ventilated room.

Appearances after Death.-Supposing death to have taken place rapidly from the liquid acid, the following appearances may be met with: The sin of the mouth and lips will present various shades of color, from orange-yellow to brown. Yellow spots produced by the spilling of the arid may be found about the hands and neck. The membrane lining the mouth is sometimes white-more commonly of a yellow color; and the teeth are white or yellowish in color. The throat and windpipe are much 1.flamed. The lining membrane of the gullet is softened, of a yellow or brown color, and easily detached, often in long shreds. The windpipe is ongested, and the lungs also. The most strongly marked changes are wen in the stomach. When not perforated, this organ may be found distended with gas, its mucous membrane partially inflamed and covered with patches of a yellow, brown, or green color, or it may be even black. Its coats may be so much softened as to break down under the slightest pressure. Similar changes are found in the duodenum; but in some cases tre small intestines have presented no other appearance than that of a sight redness. It might be supposed that the stomach would be in general perforated by this corrosive liquid; but perforation has not been. often observed. In a case of the editor's there was a small aperture in the anterior wall of the stomach, around which the peritoneum was ecchymed; but no lymph was exuded around the opening. It is probable that the rupture had taken place about the time of death, which superresed seventeen hours after the acid was taken. (Guy's Hosp. Rep., 1972, xvii. p. 223.) In a case which proved fatal after the long period of x months, there was, at the intestinal end of the stomach, a distinct istrix with puckering and hardening of the surrounding mucous memine, causing a slight contraction of the intestinal orifice. The only er appearance consisted in some dark longitudinal lines on the posterior face of the lining membrane of the gullet. These had probably ben caused by the acid. (Lancet, 1860, ii. p. 510.)

The smallest quantity of this acid which is reported to have destroyed He is about two drachms in the case of a boy, aged thirteen, who died in

100

thirty-six hours.

FATAL DOSE-CHEMICAL ANALYSIS.

Death commonly takes place within twentySoberheim relates a case of poisoning by nitric acid, which pr in one hour and three-quarters. This is believed to be the m fatal instance on record where the acid acted in the ordinar The usual well-marked effects were found in the gullet, sto small intestines. In infants, life may be destroyed by this poiso minutes, should it happen to reach the larynx. The longe perhaps, that recorded by Tartra, where a woman died from e produced by the secondary effects of the acid eight months af swallowed it.

Chemical Analysis.-In the simple state. This acid may be either concentrated or diluted. The concentrated acid varie from a deep orange-red to a light straw-yellow. It may be r 1. By evolving acid fumes when exposed to the air or when h By its staining organic matter yellow or brown, the color being and turned to an orange-red by contact with the caustic alkalies. mixed with copper-cuttings, it is rapidly decomposed, deep red a are given off, and a greenish-colored solution of nitrate of copper Tin or mercury may be substituted for copper in this experimen addition of gold-leaf and a few drops of hydrochloric acid: if is present, the gold will be dissolved on warming the mixture. aqua fortis (nitric acid) sometimes contains, as impurity, a suf hydrochloric acid to dissolve gold-leaf. It strikes a deep br with a solution of ferrous sulphate. In the diluted state.—T not precipitated like sulphuric by any common reagent, since al combinations are soluble in water. 1. The liquid has a highly tion, and (if not too diluted), on boiling it with some copper tur fumes are given off, the liquid acquiring at the same time a l 2. A streak made on white paper with the diluted acid does not it when heated; but a scarcely visible yellow stain is left. is neither precipitated by nitrate of barium nor by nitrate of silv last two experiments give merely negative results; they serve that sulphuric and hydrochloric acids are absent. 4. The liquid with an equal bulk of pure sulphuric acid, partially cooled, an solution of ferrous sulphate is gently poured on to the surfa mixture a deep brown ring forms at the junction of the two nitric acid or a nitrate is present.

3.

In order to detect nitric acid when mixed with water or othe the liquid should be first tested with litmus-paper, and also w acetate and potassium sulphocyanate, or by means of methylthe presence of a free mineral acid (see p. 97, ante). Two sepa tions should then be carefully neutralized-the one with potash, with soda, and then each slowly evaporated to obtain crystals. liquid contains nitric acid, these crystals will have the followin ters: 1. Those of nitrate of potassium will appear in the form fluted prisms, which neither effloresce nor deliquesce on exposur Those of nitrate of sodium have a 1hombic form and closely sim appearance of the cubic crystals of common salt. One drop of the evaporated spontaneously on glass, will suffice to yield distinct a formed crystals. 2. When moistened with strong sulphuric a powdered crystals of either salt slowly evolve a colorless acid vaj this test the nitrate is known from every other deflagrating sal portion of the powdered crystals should be placed in a small t mixed with an equal bulk of fine copper filings. The mass is the moistened with water, and a few drops of strong sulphuric acio

NITRIC ACID IN ORGANIC LIQUIDS.

101

Either with or without the application of a gentle heat, decomposition mediately ensues, by which red nitrous fumes are evolved, recognizable by their color, odor, and acid reaction. In operating on a small quantity of nitrate free from chloride, the crystals may be placed in a flask and mixed with one or two drops of concentrated sulphuric acid and a few copper filings. Place in the neck of the flask a slip of damp blue litmuspaper, and a slip of starch-paper moistened with a solution of iodide of potassium. After a longer or shorter interval the litmus will be reddened, and the starch-paper will assume a blue-black color. If the nitrate should be mixed with much chloride, then the power of dissolving gold-leaf on boiling the dry salt with strong hydrochloric acid furnishes the best means of detection. 4. We add to the crystals a small portion of gold-leaf and hydrochloric acid; then boil for a few minutes. If nitric acid or a nitrate is present, the gold will either partly or entirely disappear. Its partial lution will be indicated by a dark-purple or brown color on the addition of stannous chloride to the liquid after boiling.

In Liquids containing Organic Matter.-Nitric acid may be administered in such liquids as tea, vinegar, or porter. In this case, besides the acid reaction, there will be a peculiar smell produced by the strong acid, when mixed with organic substances. The application of the usual tests may be here counteracted: thus, unless the quantity of nitric acid in the quid is considerable, the orange-red nitrous acid fumes are not evolved on boiling it with copper cuttings.

The action on gold-leaf will enable a chemist to detect nitric acid in idee, tea, and similar organic liquids, even when the proportion of acid is small. Boil a fragment of gold-leaf in pure hydrochloric acid, and add waile boiling a few drops of the suspected organic liquid to the mixture. If the acid is present, the gold will be dissolved. When the acid liquid is uick and turbid, a portion of it should be placed in a tube and submitted to the process of dialysis (see p. 97, ante). Vomited matters, as well as the contents and coats of the stomach (cut up), should be boiled in water, aal filtered. If not cleared by filtration, they may be submitted to alysis, and the acid water obtained carefully neutralized with potash or la and concentrated. If by filtration we succeed in procuring a clear ed liquid, the color is of no importance. A few drops of the neutralized and concentrated liquid may be evaporated on a glass slide, and the rystals thus obtained examined microscopically and compared with those nitrate of potassium and of sodium. Paper dipped into the concentrated quid and dried burns with deflagration like touch-paper. The crystals tained by evaporating the neutralized liquid are generally colored with organic matter, but they fuse into a white mass when heated in a platinum apsule. The pure nitrate thus obtained may be tested as above described. The organic matter in the crystals does not interfere with the results of the copper and gold tests.

When either nitric acid, or the nitrate into which it has been converted, is mixed with common salt, the copper test cannot be employed. The gold test will in such a case furnish the best evidence. Hydrochloric and with a small portion of gold-leaf may be added to the dried residue, and the mixture boiled. If nitric acid or a nitrate is present, even in tute proportion, some portion of the gold will be dissolved-a fact monstrable by the addition of stannous chloride.

Nitric acid may be detected in stains on clothing, if recent, by simply bling the stained cloth in water. An acid liquid will be obtained, unless the stains are of old date or the stuff has been washed. This liquid, when concentrated, may be dealt with in the manner already described for

102

HYDROCHLORIC OR MURIATIC ACID.

organic liquids. The stains from this acid on black and blue cl a yellow or brownish-yellow color and are indelible. When lon they become dry, but the cloth is easily torn. A simple method ing the acid is to boil at once a piece of the stained cloth with a of gold-leaf and hydrochloric acid. If nitric acid is present in th portion of the gold will be dissolved.

In 1889, a man was convicted of the murder of a woman by pour acid down her throat whilst in bed (Reg. v. Lipski, C. C. C., Ju In reality a mixture of acids, containing more sulphuric than n employed. Such a mixture does not char cellulose (wood and like sulphuric acid, but converts it into nitro-cellulose, which was found by the editor in the stains on the deceased woma and also in wood cut from the floor of the room in which the mu committed.

HYDROCHLORIC ACID. MURIATIC ACID.

T

This acid, which is also called muriatic acid, and is popular under the name of spirit of salt, is often taken as a poison. In which have hitherto been observed, the symptoms and appeara been similar to those caused by nitric acid. A woman, æt. 63, s half an ounce of concentrated hydrochloric acid. She was rece the hospital in three-quarters of an hour. The prominent sympt burning pain in the throat and stomach, feeble pulse, cold, clan retching, and vomiting of a brown matter streaked with blood taining shreds of membrane. There was great exhaustion. became swollen, the patient lost the power of swallowing, and eighteen hours. She retained her senses until the last. The app in the body were as follows: The mucous membrane of the m throat was white, softened, and destroyed in many places by the action of the acid. The mucous membrane of the gullet was re flamed. The back part of the stomach near the pylorus was dar stripped of its mucous membrane (which was generally soften marked with black lines. It was not perforated (Lancet, 1859, In this case the smallest quantity of hydrochloric acid was tak has as yet been known to prove fatal.

In 1885, a man, æt. 37, was admitted into Guy's Hospital after ing, for suicidal purposes, a fluidounce of strong hydrochloric which he had dissolved a dram of oxalic acid. The ordinary were employed, and he progressed favorably till the tenth day, died rather suddenly. On post-mortem examination the editor membranous exudation and minute ulcers at the back of the The mucous membrane of the gullet was white, thickened, and inte with small extravasations of blood. The stomach contained re food of the ordinary acidity. The mucous membrane was w mammillated. Towards the pyloric or intestinal end there we ulcers with open blood vessels, from the mouths of which exten siderable extravasations of blood blackened by the action of the the stomach. Between the ulcers the surface was raw and hem The hemorrhage extended into the duodenum, but not beyond.

Chemical Analysis.—In a concentrated state, hydrochloric acić copious fumes. The pure acid is nearly colorless; the commercia of a lemon-yellow color, and frequently contains iron, arsenic, salt, and other impurities. When boiled with a small quantity of of manganese, chlorine is evolved. It does not dissolve gold-lea

fow drops of nitric acid, have been added to it, and the mixture is heated. In the diluted state, it may be recognized by the dense white precipitate which it gives when a solution of nitrate of silver is added to it. This ¡recipitate is insoluble in nitric acid, but soluble in ammonia; it becomes purple when exposed to light; and when heated it melts without decomition, forming a yellowish-colored solid in cooling. If the acid is conained in organic liquids in moderate quantity, it admits of separation by distillation to dryness. In this case any chlorides present are left in the retort. It may also be procured by dialysis in a pure enough state for testing (see p. 97, ante). In all cases the presence of a free mineral acid Lust be ascertained (see p. 97, ante).

Hydrochloric acid, in small. quantity, as well as alkaline chlorides, is a "atural constituent of the fluids of the stomach and bowels. The presence of local chemical changes in the throat and stomach would show whether the acid had been taken as a poison. If the acid is found only in minute quantity, no inference of poisoning can be drawn, unless there are distinct harks of its chemical action upon the throat and stomach. It darkens the blood like sulphuric acid, although it has not the same degree of caronizing action on organic matter. The stains produced by this acid on lack cloth are generally of a reddish color. As the acid is volatile, it tay disappear from the stuff. If recent, the acid may be separated by boiling the stuff in water and applying the silver test, and the tests for a free mineral acid (see p. 97, ante). An unstained portion of cloth should Le similarly tested for the sake of comparison.

[NITRO-HYDROCHLORIC ACID. (AQUA REGIA.)

The general symptoms, effects, and post-mortem appearances resemble those of the preceding acid. The test is its solvent power over gold. Its dorine can be detected by the odor evolved and also by nitrate of silver; Its nitric acid, by the action on copper in the cold. (Reese.)]

CHAPTER VIII.

OXALIC ACID.-SYMPTOMS AND APPEARANCES.-CHEMICAL ANALYSIS.-DIALYSIS OF ORGANIC LIQUIDS.-ACID OXALATE OF POTASSIUM, OR SALT OF SORREL.-VEGETABLE ACIDS.

OXALIC ACID.

Symptoms. If this poison is taken in a large dose, i.e. from half an ounce to an ounce of the crystals, dissolved in water, a hot, burning, acid taste is experienced during the act of swallowing the poison. This is accompanied by a similar sensation extending down the gullet to the stomach. There I sometimes a sense of constriction or suffocation: the countenance is livid, and the surface of the skin soon becomes cold and clammy. VomitJag occurs either immediately or within a few minutes. Should the poison be much diluted, there is merely a sensation of strong acidity, and Vomiting may not occur until after a quarter of an hour or twenty minutes. In some cases there has been little or no vomiting, while in others this symptom has been incessant until death. In one case, in which an ounce