CORROSIVE POISONS
THE MINERAL ACIDS
General Characters.—The mineral acids have no remote effects on the system; their action is purely local. They are seldom used for the purpose of homicide, except in the case of young children. By suicides they are more frequently employed.
The Symptoms common to the action of these acids supervene immediately the acid is swallowed, and consist in a sensation of burning in the mouth and gullet. Dreadful pain is felt in the stomach, attended with constant eructations, and vomiting of a brownish or blackish matter, mixed with blood. Mucus, together with, in severe cases, portions of the mucous membrane of the stomach, may be detected in the vomited matters, which have an intensely acid reaction, changing the colour and destroying the texture of cloth or other material on which they may fall. The act of swallowing is attended with intense pain, and not infrequently is rendered quite impossible. The thirst is intense, the bowels are confined, and the urine is diminished in quantity. The pulse is small and weak, and the skin clammy and cold. Respiration is performed with difficulty, and the countenance expresses the most intense anxiety. Sometimes, when the upper part of the windpipe is implicated, there is more or less cough and difficulty of speech. Death may even result from suffocation—the skin, in this case, presenting a cyanosed appearance. The mouth is excoriated, the lips shrivelled and blistered. In children, when the acid has been poured far back into the mouth, by forcing the bottle backwards before emptying it of its contents, the mouth may more or less escape injury, and the signs in it of corrosive poisoning be absent. The teeth may become loose, and fall out of the mouth. The mental faculties remain clear, death generally coming on suddenly, the patient dying convulsed or suffocated. The period at which death ensues is very variable, and considerable power for locomotion may be retained by the sufferer, though, as a rule, he is found writhing in exquisite agony on the floor or elsewhere. Some cases recover, leaving the coats of the stomach more or less injured, and the general health greatly impaired.
Post-mortem Appearances.—The body externally is healthy. The lips and external parts of the body, which have come in contact with the acid, are charred. The mucous membrane of the mouth, shrivelled and eroded, is whitish, yellowish, or brownish, sometimes appearing “as if it had been smeared with white paint” or thin arrowroot. Many of the appearances above described will depend upon the rapidity with which death has followed the swallowing of the poison. The mouth, gullet, and trachea may alone show any signs of the corrosive action of the poison, and it is important to remember that death may be due to sulphuric acid, and yet the acid may never have reached the stomach. In one or two cases where the poison was poured into the mouth during sleep, and in the case of children in whom the mouth was held open, there were no signs of the poison on the lips, and the mouth even escaped in one or two cases. The stomach, in some cases more or less contracted and perforated by the corroding action of the acid, may contain a dark grumous liquid, the acidity of which will depend upon the treatment adopted, or the length of time that may have elapsed from the swallowing of the acid to the fatal termination. The stomach also appears as if carbonised, this being due to the action of the acid on the effused blood; no such appearance being produced when sulphuric acid is poured into the dead stomach. Corrosive action may be found in the duodenum. In cases where the patient has survived from sixteen to twenty hours, the small intestines have been found inflamed. The blood, Casper states, is never fluid in acute poisoning by sulphuric acid, but always “syrupy at least, and sometimes ropy; it has a cherry-red colour, and acid reaction.” Sulphuric acid is also said to possess powerful antiseptic properties, and that bodies of those who have died from its effects remain long fresh.
There are two things which may render the diagnosis difficult—(1) Gastric ulcer. (2) Post-mortem digestion of the stomach.
Gastric ulcers vary in size from that of a threepenny-piece to that of a florin, or larger. In shape they are round or oval, and present the appearance of shallow but level pits, with sharp, smooth, vertical edges—appearing as if they had been punched out. The peritoneal opening is smaller than that on the internal surface of the stomach. The absence of injury to the mouth and gullet will distinguish gastric ulcer and post-mortem softening from the action of corrosive poisons.
General Treatment.—Chalk, carbonate of magnesia, bicarbonate of soda, the plaster from the walls or ceiling of the apartment stirred in water, and followed by diluent drinks—barley water, linseed tea, &c. The use of the stomach pump is contra-indicated.
SULPHURIC ACID
Forms.—Sulphuric acid occurs in two forms—concentrated and diluted.
Characters.—Concentrated sulphuric acid or oil of vitriol (specific gravity, 1.800 to 1.845), as it is found in commerce, is a heavy, oily, colourless, or slightly brownish-coloured liquid, not fuming when exposed to the atmosphere; but, when added to water, causing a rapid increase of temperature, which may crack the glass vessel in which the mixture is made. Sulphuric acid chars and destroys the texture of organic bodies placed in it. Dilute sulphuric acid is a colourless, strongly acid liquid, reddening litmus, and charring paper dipped into it when subsequently dried, care being taken not to scorch the paper.
Symptoms, &c.—The symptoms and post-mortem signs have been already described, [p. 246].
Chemical Analysis and Tests.—The acid will have to be examined under the following heads: (1) Simple, concentrated acid. (2) Dilute acid. (3) Mixed with organic liquids, food, vomit, &c. (4) On the clothes of the person injured.
I. Concentrated Acid
1. Chars Organic Matter.—A piece of wood or paper placed in the strong acid rapidly becomes blackened.
2. Heat when added to Water.—Equal quantities of acid and water added together produce intense heat.
3. Evolution of Sulphurous Acid.—When boiled with chips of wood, copper cuttings, or mercury, fumes of sulphurous acid are evolved, detected by their sulphur-like odour, and by their power of first bluing and then bleaching starched paper dipped in iodic acid.
II. Dilute Acid
1. Chars Paper.—This only occurs when the paper is dried by the aid of heat, subsequently to moistening it in the dilute acid.
2. Precipitation of Sulphate of Barium.—A solution of the nitrate or of the chloride of barium is precipitated by sulphuric acid in the form of a white insoluble powder, unaffected by nitric or hydrochloric acid, even when heat is applied. This test is so delicate, that a liquid containing ¹/₂₅₀₀₀th part by weight of the acid is precipitated by either of the test solutions.
3. Action of Heat.—The dilute acid is entirely volatilised by heat.
III. Mixed with Organic Liquids, &c.
In tea, coffee, or beer the mode of applying the tests are the same, the mixture being previously filtered, or the acid separated from the organic mixture by dialysis, or the following cautions are necessary:
Objection A.—Alum, or any acid sulphate, would give all the reactions with the nitrate and chloride of barium.
Answer A.—Evaporate a portion of the doubtful liquid; if pure acid, there will be no residue, sometimes only the slightest trace of sulphate of lead.
Objection B.—Erroneous estimation of free sulphuric acid, in consequence of the presence of some saline or neutral sulphates.
Answer B.—Evaporate as before. The free sulphuric acid separated by warming the liquid is then added to a known weight of powdered carbonate of baryta until effervescence ceases. The resulting precipitate when weighed, represents the free sulphuric acid present.
Calculate in the following manner—
- BaCO₃ + H₂SO₄ = BaSO₄ + H₂O + CO₂.
- BaCO₃ = 197.
- H₂SO₄ = 98.
- CO₂ = 44.
In the above equation, 98 parts of H₂SO₄ take the place of 44 parts of CO₂. If, therefore, 100 grains of BaCO₃ renders the liquid neutral, the amount of free SO₄ present will be represented by the increased weight of the precipitate in the proportion of 54 to 98, the difference between 44 and 98 the equivalent of CO₂ + SO₄.
To extract the acid from organic mixtures, digestion with alcohol is required: filter and neutralise the filtrate with caustic potash, evaporate to dryness, and dissolve the residue in distilled water acidulated with hydrochloric acid; the previous tests may then be applied. Extraction with alcohol leaves behind combined acid in the form of sulphates. The presence of free acid in the filtrate or original mixture may be detected by the change of tropæolin solution from yellow to crimson or ruby colour when added to it; or on adding a few drops of the mixture or filtrate to a solution of potassio-tartrate of iron B.P. in water, so as to make it of a yellow tinge, and to which potassium sulphocyanide has been added, the liquid changes from a yellow to a port-wine colour.
IV. Stains on the Clothes, &c.
1. The strong acid changes the colour of black woollen cloth to a dirty brown, the edges of the spots assuming a reddish tint after a few days. The dilute acid on the same cloth produces a red stain, which in time becomes brown.
2. The spots made by the strong acid remain damp for some time—strong sulphuric acid, having a great affinity for water, continually absorbs moisture from the atmosphere.
3. The spot should be cut out, boiled in distilled water, or digested with alcohol, filtered and tested for free sulphuric acid.
4. A portion of the cloth not touched by the acid should be tested, in order to show that the sulphuric acid found is not due to sulphates present in the cloth.
5. An acid sulphate—bisulphate of potash—gives a reddish stain to black cloth like that produced by the dilute acid. Test for this salt by incineration.
Fatal Period.—Average time before death ensues is from two to twenty-four hours. The shortest time was one hour, but in children death may be instantaneous. Life, however, may be prolonged for some weeks, or even months.
Fatal Dose.—One drachm in a healthy adult has proved fatal; on the other hand, however, four ounces have been swallowed without being fatal.
Treatment.—As before mentioned.
N.B.—This acid in past years has given rise to several actions, it having been employed to disfigure the person by throwing it in the face.
NITRIC ACID
Forms.—Strong nitric acid, and dilute nitric acid.
Characters.—This acid is commonly known as aqua fortis, or red spirit of nitre. It is seldom used as a poison.
The strong acid varies in colour from a pale yellow to a deep orange. The colour is due to admixture with peroxide of nitrogen. On cloth and articles of dress it produces yellow stains, which are darkened by the application of an alkali. If poured on copper cuttings, reddish fumes of nitrous acid are given off. Dilute nitric acid is a colourless acid liquid, not precipitated by nitrate of barium or nitrate of silver, showing absence of sulphuric and hydrochloric acids. All its alkaline salts are soluble in water.
Symptoms.—The symptoms have been before described, and are similar to those produced by sulphuric acid, though not quite so severe. The vapour of this acid has caused death in eleven hours by congestion of the bronchial tubes and lungs; care should, therefore, always be taken not to inhale the fumes given off by the acid in the manufacture of gun-cotton, &c.
Post-mortem Appearances.—Same as the mineral acids generally, but the tissues touched are turned yellow, and if bile be in the stomach it is turned green. The stomach is rarely perforated.
Chemical Analysis.—Nitric, like sulphuric, acid will be examined under four heads; but being a volatile acid, easily decomposed, and also having its nature changed by contact with organic substances, its presence on clothes may fail to be detected after a few weeks. The colour of the stain on cloth may also remain, although the acid has been entirely removed by washing. 1. Strong, concentrated acid. 2. Dilute acid. 3. Mixed with organic liquids, &c. 4. On the clothes of the person injured.
I. Concentrated Acid
1. Volatility.—When exposed to the atmosphere, strong nitric acid gives off colourless or orange-coloured acid fumes. Heated in a watch-glass, it is evaporated without residue.
2. Action on Organic Matter.—The acid leaves on woollen clothes a yellow-coloured stain, which is darkened by the addition of an alkali. The colour of the stain is due to the formation of picric acid.
3. Action on Metals.—Gently heated in a test tube with copper filings, orange-coloured fumes are given off, which redden but do not bleach litmus paper. Starch paper treated with iodide of potassium becomes purple.
4. Solution of Gold.—If a small portion of gold leaf be put into the acid, no effect is produced; but on the addition of concentrated hydrochloric acid, the metal is rapidly dissolved.
II. Dilute Acid
1. Absence of sulphuric and hydrochloric acids, proved by no precipitate being formed with nitrate of barium and nitrate of silver.
2. It does not char paper when the paper is heated, as is the case with sulphuric and hydrochloric acids.
3. If a piece of filtering paper be dipped into a solution of the acid saturated with carbonate of potash, dried and ignited, it will burn like touch-paper.
4. The acid liquid, saturated with carbonate of potash and evaporated, deposits fluted prisms which do not effloresce or deliquesce on exposure. Neutralised with soda, the crystals are of a rhombic form.
5. A crystal, so formed, moistened with distilled water on a plate, and then heated with strong sulphuric acid and allowed to cool, gives with—
(1) A piece of green sulphate of iron—a dark green ring round the crystal.
(2) A small portion of morphia—a rich orange colour, a yellow liquid being formed.
(3) A small portion of brucine—a blood-red colour.
6. If an aqueous solution of diphenylamine be added to a solution containing nitric acid, in a test tube, and pure sulphuric acid be poured down the side of the tube to form a layer at the bottom, a blue colour forms at the junction of the two liquids.
III. Mixed with Organic Liquids, &c.
Due to the measures employed by way of treatment the vomited matters may be neutral and yet nitric acid be present. The method adopted with viscid and turbid organic mixtures is to dilute them with pure water, and then filter. If the filtrate be acid, it is neutralised with carbonate of potash, evaporated, and then set aside to crystallise, and the crystals purified by digesting them in ether or alcohol. The crystals are again dissolved and re-crystallised. The tests just mentioned should then be employed. It should be remembered that nitric acid has a strong tendency to combine with solid organic structures, and to become decomposed. The parts of the body stained by the acid should, therefore, be digested in water at a gentle heat, the liquid cooled, filtered, and neutralised with carbonate of potash, and then examined for nitre.
IV. Stains on the Clothes, &c.
Macerate the piece of cloth in distilled water by the aid of heat. If the solution be acid, neutralise with carbonate of potash, and filter. Test the solution as before mentioned.
The action of the dilute solution of caustic potash on the following stains on cloth is characteristic: Nitric acid stain becomes of a clear orange tint. Iodine stain disappears. Bile stain remains unchanged.
Fatal Period.—Death may take place in an hour and a half, or life may be prolonged for some months.
Fatal Dose.—Two drachms; recovery has taken place after half a fluid ounce of the strong acid has been taken.
Treatment.—As before mentioned when speaking of the acids generally.
HYDROCHLORIC ACID
Forms.—Strong and the dilute acid. It is known as muriatic acid, or spirits of salts.
Characters.—Strong hydrochloric acid is either colourless or has a bright yellow tint, due to the presence of the perchloride of iron. It fumes in the air, and gives rise to dense white fumes when a glass rod moistened with ammonia is held over the surface of the acid. The dilute acid is colourless.
Symptoms.—Poisoning with muriatic acid is so rare that the symptoms have not been well studied, but they do not appear to differ much from those produced by the action of the other acids. It does not stain the skin, but may darken the mucous membranes. The fumes are apt to attack the air-passages.
Chemical Analysis.—The acid will have to be examined under the following heads: 1. Simple, concentrated acid. 2. Dilute acid. 3. Mixed with organic liquids, food, &c. 4. On the clothes of the person injured.
I. Concentrated Acid
1. Action on Organic Matter.—The strong acid tinges most organic tissues, when immersed in it, a yellow colour. The stains on black cloth are at first distinctly red, becoming reddish-brown after a few days.
2. Action on Metals.—This acid does not act on copper or mercury, even when boiled with them, and this distinguishes it from the other acids.
3. Hydrochloric acid, added to peroxide of manganese and then warmed, gives off chlorine gas, detected by its greenish-yellow colour and suffocating odour. The vapour thus produced bleaches litmus paper, and causes a blue coloration on starch paper moistened with iodide of potassium.
II. Dilute Acid
1. Decomposes alkaline carbonates, chlorides being formed which, when heated in the solid state with strong sulphuric acid and peroxide of manganese, evolve chlorine gas, known by the before-mentioned tests.
2. Precipitation of Chloride of Silver.—A white curdled precipitate of chloride of silver is thrown down when a solution of nitrate of silver is added to hydrochloric acid. This precipitate becomes grey on exposure to light. If a portion of the precipitate be added to ammonia it will dissolve; another portion, when boiled with nitric acid, is unaffected; and a third portion, ignited in a capsule, becomes converted into a horny mass.
In any case where there is a doubt as to whether the hydrochloric acid exists in the free state, or is only present in the form of chlorides, the following test should be resorted to, which will not only discriminate between the two forms, but give the relative amount of each present:
Take two equal measures of the acid liquid. Precipitate one with nitrate of silver, after the addition of nitric acid, and weigh the precipitate. Evaporate the second portion of the acid liquid to dryness, and dry the residue in a water bath; dissolve this residue in distilled water, and treat the solution with nitrate of silver as before, weighing any precipitate which occurs. The weight of chloride of silver obtained from the first portion of the liquid will give all the hydrochloric acid present, both in the free state and in combination; while the weight of the silver precipitate in the second portion of liquid only gives the chlorides, all free—hydrochloric acid having passed off during the process of evaporation.
III. Mixed with Organic Liquids, &c.
The suspected acid liquid should be filtered, and then distilled almost to dryness. The portion of the distillate which comes over at first may be thrown away; but the latter portion will give all the reactions before described for hydrochloric acid, if that be present. Distillation is adopted in the case of this acid, as it is more volatile than either sulphuric or nitric acid. It may be objected that the acid found in the vomited matters is from the gastric juice. In answer to this, it may be stated that the free hydrochloric acid in normal gastric juice is only about five grains in sixteen ounces, an amount which would give but slight reaction with the tests.
IV. Stains on the Clothes, &c.
The spots produced by the action of the acid on black cloth are at first of a bright red colour, changing in ten or twelve days to reddish-brown. These spots may be cut out and macerated in warm water; the liquid thus obtained then tested by nitrate of silver and the other tests before noticed. Another portion of the cloth should be treated in the same manner, and the resulting liquid tested, as a control against the objection that the acid might have been present in the cloth. Hydrochloric acid has been used to erase writing from paper in attempts at forgery, &c. The paper must be treated in the same manner as mentioned for the cloth, and the tests used. Sometimes oxalic acid is employed for a like purpose, in which case the nitrate of silver will give a precipitate; but the oxalate of silver is soluble in nitric acid; the chloride is not soluble even when boiled.
Fatal Period.—From two or five hours to thirty hours or more.
Fatal Dose.—One fluid drachm to one ounce; recovery has taken place after swallowing two fluid ounces.
Treatment.—The same as for the other acids.
Table showing the Colour produced by
the Action of the Mineral Acids
on the Skin and on Cloth
| Skin. | Cloth. | |
|---|---|---|
| Sulphuric acid. | Brown colour. | Dirty-brown edges becoming |
| red after a few days from | ||
| absorption | ||
| Nitric acid. | Bright yellow, due to | Yellow, orange-red, or brown. |
| the formation of | ||
| picric acid. Colour | ||
| heightened by | ||
| alkalies. | ||
| Hydrochloric acid. | Greyish-white. | Bright red changing after some |
| days to reddish-brown. |
SULPHATE OF INDIGO
A dark blue liquid formed by dissolving indigo in strong sulphuric acid. Used as a dye. The symptoms are much the same as those detailed under sulphuric acid, with the additional bluing of the mouth and lips. It may be detected with the tests given under sulphuric acid, the blue colour being first discharged by boiling it with nitric acid.
CARBOLIC ACID
Phenol. Phenic Acid. Coal-tar Creosote. Oil of Tar
Carbolic acid is obtained in the dry distillation of coal, and forms the acid portion of coal-tar oil, from which it is subsequently extracted by shaking the crude coal-tar oil with a mixture of slaked lime and water. After allowing the mixture to stand for some time, the watery portion is separated from the undissolved oil, the former treated with hydrochloric acid, and the resulting oily fluid purified by careful distillation. Up to the year 1900 no restrictions were put upon the sale of carbolic acid, but owing to the large number of suicidal and accidental deaths from its use, it was by Act of Parliament scheduled as a poison, and all preparations containing more than 3 per cent. of it, cresylic acid, or their homologues, must be sold as poisons.
Pure carbolic acid forms long, colourless, prismatic needles, which melt at 35° C. into an oily liquid. It boils at 180° C., and greatly resembles creosote, for which it is very frequently substituted in commerce, but from which it differs in the following characters: It does not affect polarised light as creosote does; it forms a jelly-like mass with collodion, and is soluble in a solution of potash, whereas creosote is unaffected by collodion, and is insoluble in a solution of potash. It possesses a penetrating, characteristic odour; burning taste; is slightly soluble in water, but freely so in glycerine, ether, and alcohol; and gives no acid reaction to test paper. When undiluted, it attacks the skin, which it shrivels up.
Creosote is obtained from wood-tar, which imparts to it its caustic properties.
Carbolic acid acts as a corrosive and anæsthetic on the skin and mucous membranes, and as a narcotic on the brain. Its poisonous properties are exerted whether it be swallowed or merely applied to the skin, especially if a wound be present.
Effects on the Skin, &c.—Strong carbolic acid, when applied to the skin, corrugates, hardens, and destroys its sensibility, and is said to whiten it; though in one case, in which the crude acid had been taken with a suicidal intent, there was after death a dark brownish ring about half an inch wide surrounding the mouth; and in another, that of a child who, in climbing to a shelf, poured over its face and neck about half a saucerful of diluted acid, the colour of the skin touched by the acid was yellowish-white and yellowish-brown, dry and parchment-like. The action of the acid on the mucous membranes is similar to that on the skin, but the corrugation is more marked, and considerable softening and peeling may also take place.
Effects on the Nervous System.—Rapidly supervening stupor, total muscular relaxation, anæsthesia, and stertorous breathing are among the most prominent symptoms. Nearly all the sufferers die comatose. Carbolic acid appears to act principally on the central nervous ganglia at the base of the brain and on the spinal cord. The evidence is more in favour of its action on the brain than on the spinal cord, and not at all on the periphery of the nerves. The muscles contract vigorously after death, in response to galvanic stimulation applied either to the nerves or to the muscles themselves.
Effects on the Circulation.—The action of carbolic acid on the circulation has not yet been fully worked out, but it appears to be a cardiac depressant, the heart being arrested in diastole.
General Symptoms.—As soon as the acid is swallowed, the patient complains of intense burning pain in the mouth, throat, and stomach, the pupils are contracted, the conjunctiva insensible to touch, the skin cold and clammy, the temperature rapidly falls, and the pulse becomes weaker and weaker, till it is almost imperceptible. The breathing is laboured, and, as the fatal issue approaches, becomes stertorous; vomiting of frothy mucus occurs in some cases. The invasion of the symptoms is most rapid, and many of the patients have been in an insensible condition when found. The above symptoms have even supervened when the strong acid has been used for dressing wounds.
Dr. J. Hamilton records a case where the acid was used as an application to a wound four inches long, in a child four and a half years of age. Direct contact of the acid with the wound was prevented. About an hour after the dressing was applied he saw the patient, who was then supposed to be suffering from the effects of chloroform used during the operation on the child‘s arm. She was suffering from symptoms like those before described. On removing the dressing, some of the carbolic acid, it was found, had melted and run into the wound, and to this Dr. Hamilton attributed the symptoms. The child ultimately died. (See British Medical Journal, 1873, vol. i. p. 226.)
The urine and fæces, when passed, are of a dark colour, and it has been frequently noticed that the urine passed by the assistants in surgical hospitals, who, under the antiseptic methods adopted, are constantly washing their hands in solutions of carbolic acid, is of an olive-green colour. This shows that absorption takes place readily through the skin. Bilroth, in his work on Clinical Surgery, gives several instances of absorption in this way. Nephritis with casts in the urine may occur. The hypodermic administration of carbolic acid, twelve to twenty-four grains in a day, has failed in five cases under my observation to be followed by carboluria.
Post-mortem Appearances.—If the poison has been drunk, a dark brownish horny rim may be found soon after death round the lips; the mucous membrane of the mouth and stomach is whitened, corrugated, and softened, and looks as if smeared with white lead—in some cases, horny in patches; inflammatory signs being absent or only slightly visible. The blood is uniformly fluid, becoming a bright red on exposure. The smell of carbolic acid is detected in the stomach, and sometimes in the small intestine, and even in the spleen, liver, and kidneys. In Dr. Ferrier‘s case, the urine found in the bladder after death had a slight olive-greenish tint with a peculiar mixed odour, which gave the usual reactions to the tests for carbolic acid. The dark colour of the urine is not due to the presence of hæmin, as the urine, in poisoning by carbolic acid, does not contain more than a normal amount of iron; the colour is, therefore, probably due to some product formed by the partial oxidation of the acid as hydroquinone. Signs of nephritis may be present. The left ventricle of the heart is, in most cases, found contracted, the right flaccid. The lungs are congested, and this may also be the case with the vessels of the brain; but there may be an entire absence of any post-mortem signs to point to the probable cause of death, where the poison has gained entrance through a wound when the acid has been used as a surgical dressing.
Chemical Analysis.—Carbolic acid may be separated from mixture with organic substances by distillation with dilute sulphuric acid, from urine by agitation with ether. Bromine water, as recommended by Landolt, gives a bulky yellowish precipitate of tribromo-phenol. The precipitate should then be collected, well washed, and gently warmed in a test tube with sodium-amalgam and water. The liquid poured into a dish and acidulated, will, if phenol be present, give the characteristic odour of that substance, and it may be seen floating in the liquid as an oily fluid. By this test, one part of phenol in 43,700 of water may be detected. It must be remembered that, according to Landolt, carbolic acid is normally present in the urine, but Hoppe Seyler contends that it is not originally present in urine, but is formed by the action of sulphuric acid, probably from indican. Carbolic acid urine, treated with nitric acid, and then with potassæ, and concentrated, becomes blood-red, brown-red, and then changes from pea-green to violet. Carbolic acid mixed with urine does not give the above reactions (Schmidt‘s Jahrbücher, Bd. clxiv. p. 144).
A solution of carbolic acid, mixed with one-fourth of its volume of ammonia and a few drops of bleaching powder solution (1 in 20 of water), and then warmed, but not boiled, assumes a blue colour (green in very dilute solutions), becoming red on the addition of sulphuric or hydrochloric acid. The perchloride of iron gives a violet colour with carbolic acid.
Fatal Period.—Death has occurred in three minutes; also delayed to sixty hours; usually three to four hours.
Fatal Dose.—One drachm has caused death in twelve hours. A child six months old died from the effects of a quarter of a teaspoonful of a solution of one part of the acid to five of glycerine. Recovery has taken place after an ounce of 90 per cent. strength liquefied acid, also after four ounces of the crude acid; after six ounces of the crude acid, 14 per cent. strength; and in a child of two after half an ounce of crude acid of 30 per cent. strength.
Treatment.—Stomach pump. Wash out the stomach with equal quantities of alcohol and water mixed—whisky, brandy, gin, or rum will do until absolute alcohol or rectified spirit be obtained. The washing should be repeated every 5 to 15 minutes from four to eight times; apomorphine hydrochlorate gr. ⅒ should be given hypodermically at the commencement, and the administration of demulcent drinks. Emetics are of little or no use, owing to the anæsthesia of the mucous membrane of the stomach. The sulphate of soda, Glauber salts, has been proposed as an antidote. Any soluble sulphate may be tried. Oil or vinegar is the best outward application to the skin, after washing with spirit of wine or methylated spirits.
OXALIC ACID
This is a powerful corrosive and cardiac poison, but on account of its strongly acid taste it is ill-adapted for the purposes of the murderer. Deaths have not infrequently followed the accidental substitution of this substance for Epsom salts—sulphate of magnesia—which it somewhat closely resembles.
The ordinary crystals of oxalic acid are in the form of four-sided prisms, colourless, transparent, odourless, or with a slight acid smell, very acid taste, and not deliquescent in the air. It is largely used in the arts, by brass-polishers, straw-bonnet makers, book-binders, and others. The acid is also used to remove writing-ink from parchment, paper, &c., for the purposes of forgery, &c.
Symptoms.—These present many strange anomalies. In a large dose—an ounce or more—oxalic acid acts as a corrosive; in a smaller, as an irritant; and in a still smaller dose, as a cardiac sedative. Death has been known to occur so rapidly as to prevent any attempt at treatment. When the dose is large, an acid taste is experienced during swallowing, followed by burning pain in the throat and stomach. Vomiting then sets in, and in most cases continues till death, which may, however, occur when this symptom has existed from the first. The vomited matters may be simply mucus, mucus and blood, or dark coffee-grounds-looking matter. Unless the case is protracted, the bowels are rarely much affected, though purging and tenesmus have been noticed. Occult blood may be present in the fæces. Collapse now sets in; the pulse becomes feeble and scarcely perceptible, the skin cold and clammy, showing the action of the poison on the heart probably through the central nervous, as well as through the intra-cardiac ganglia. Should the treatment adopted prove successful, and life be prolonged, the patient complains of tenderness of the mouth, soreness of the throat, and painful deglutition. Pressure over the abdomen causes pain. Vomiting and purging are also frequently present; and if recovery takes place, convalescence is generally very gradual. The urine may contain a large quantity of albumen, casts are numerous, and oxalates in crystal form are present.
Fig. 28.—Photo-micrograph of crystals of oxalic acid, × 50.
(R. J. M. Buchanan.)
Oxalic acid acts as a poison when applied to a wound in any part of the body; and although this substance undoubtedly acts on the brain through the medium of the blood, it is a remarkable fact that it cannot be detected in that fluid, even when injected into the femoral vein of an animal which died in thirty seconds (Christison). Leeches, it is recorded, have been poisoned by the blood drawn by them from persons suffering from oxalic acid poisoning. The blood does not appear to undergo any physical change. Unlike the mineral acids, oxalic acid is still poisonous even when its corrosive and irritant properties have been destroyed by dilution.
Post-mortem Appearances.—The mucous membrane of the mouth, tongue, and throat is corrugated, white, and softened. The tongue is sometimes of a brownish colour, and sordes appear on the teeth. The stomach is in some cases pale, soft, and very brittle, and contains a dark, grumous, acid liquid; at other times it presents several semi-gelatinous spots, looking as if they had been boiled. Enlarged blood-vessels filled with dark-coloured blood are also seen ramifying over the internal surface of the organ. Perforation is of rare occurrence. The intestines generally escape with some slight inflammatory redness, unless the case is unusually prolonged. In some cases the stomach is quite healthy, no morbid appearance being found in any portion of the alimentary canal.
Fig. 29.—Photo-micrograph of crystals of oxalic acid, × 50.
(R. J. M. Buchanan.)
Chemical Analysis.—From organic mixtures the acid may be separated by dialysis, and the tests applied, or it may be obtained in crystals by precipitating it from the boiled and filtered organic mixture with acetate of lead. The precipitate washed is then decomposed by sulphuretted hydrogen and filtered, the filtrate concentrated to drive off excess of sulphuretted hydrogen, and then set aside to crystallise, which, if the acid be present, it does in slender prisms. From the contents of the stomach the acid may be separated by partial drying over a water bath, extraction with hot alcohol acidulated with a little hydrochloric acid, filtering the alcoholic solution, evaporating to dryness, and dissolving the residue in water. Should, owing to the treatment adopted, oxalate of lime in white chalky masses be found in the stomach, these should be washed and then boiled with pure carbonate of potash. A partial decomposition takes place, insoluble carbonate of lime and soluble oxalate of potash are present in the liquid, which, when filtered and neutralised with nitric acid, may be tested with the following reagents:
1. Nitrate of silver gives a white precipitate, soluble in cold nitric acid; the precipitate dried and heated on platinum foil is dissipated in a white vapour with slight detonation.
2. Calcium chloride or sulphate produces a white precipitate with oxalic acid; the test is more delicate if the acid be first neutralised with ammonia. The precipitate is immediately dissolved by hydrochloric or nitric acid, but not dissolved by oxalic, tartaric, acetic, or other vegetable acid. Lime-water should not be used as a test, as it gives precipitates with other acids; the sulphate largely diluted is not open to this objection.
3. Lead acetate gives a white precipitate soluble in nitric acid. On clothes, parchment, &c., the spot or spots must be well boiled, and the above tests applied to the solution. The stains may vary from a brownish-red to orange-red colour.
Fatal Dose.—Three drachms have caused death in one hour; sixty grains caused the death of a boy sixteen years of age, but recoveries have been known to take place after an ounce and an ounce and a half had been swallowed.
Fatal Period.—Death has resulted in ten minutes from a dose of one ounce. The shortest period has been three minutes. The time varies with individuals, even when the same quantity is taken. In the case of two girls who each swallowed an ounce of oxalic acid, one died in ten minutes, and the other in thirty minutes. Death usually takes place within from half an hour to an hour, although it has been delayed for five days.
Treatment.—Water should not be given, as it increases the solubility of the acid, and thus assists in the more extensive absorption and diffusion of the poison. The carbonates of potash and soda should be avoided, as the oxalates of these alkalies are themselves poisonous. The stomach tube should not be used. Lime is the best antidote, as the oxalate of lime is insoluble, and may be given in the form of common whiting; a pint of saccharated lime water may be given. Vomiting should be promoted. In the stage of collapse the case must be treated on general principles.
Essential Salt of Lemons
The binoxalate of potash or salt of sorrel, or, as it is more commonly known, salt of lemons, occurs as a constituent of many plants. The common sorrel—Rumex acetosa—contains it in large quantities.
Symptoms.—Those of poisoning by oxalic acid, on which its poisonous properties depend.
Post-mortem Appearances.—Inflammation of the stomach and intestines. Other appearances as in oxalic acid.
Chemical Analysis.—[See oxalic acid]. The incinerated salt leaves a white residue of potassium carbonate; oxalic acid leaves no residue.
Fatal Period.—Eight minutes in the case of a lady recently confined, who took half an ounce of the salt by mistake for cream of tartar.
Fatal Dose.—Half an ounce.
Treatment.—The same as recommended for poisoning by oxalic acid.
Table showing Symptoms, Post-mortem Appearances,
Fatal Dose, Period of Death, and
Treatment of Poisoning by
| Sulphuric Acid. | |
| Symptoms | Burning pain in the mouth, |
| throat, and gullet. Constant | |
| vomiting of brownish or blackish | |
| matter containing blood. | |
| The lips shrivelled, blistered, | |
| and excoriated; and the corners | |
| of the mouth show signs | |
| of the corrosive action of the | |
| poison. Collapse and death. | |
| Post-mortem Appearances | Presence of the signs of powerful |
| corrosion; perforation of the | |
| stomach, which is blackened | |
| and softened. | |
| Fatal Dose | One drachm. |
| Fatal Period | One hour. Average about ten hours. |
| Treatment | Magnesia, chalk, whiting, soap suds, |
| milk, and mucilaginous drinks. | |
| Hydrocyanic Acid. | |
| Symptoms | Giddiness, insensibility, difficult |
| respiration, dilated pupil, | |
| tetanic spasms, and convulsions. | |
| In acute cases, death by shock; | |
| in those more prolonged | |
| suffocation ends the scene. | |
| Post-mortem Appearances | Face pale and countenance composed; |
| congestion of the brain, and traces | |
| of inflammation in the stomach | |
| and bowels. Odour of prussic acid | |
| may be detected in most cases in the | |
| stomach and other parts of the body. | |
| Fatal Dose | About 45 minims of the |
| Pharmacopœia acid. | |
| Fatal Period | Two to five minutes. |
| Treatment | Chlorine in vapour and in water, and |
| the mixed oxides of iron. Cold | |
| affusion to the head and face, | |
| galvanism, artificial respiration, &c. | |
| Oxalic Acid. | |
| Symptoms | Burning pain in the mouth and |
| throat, vomiting of greenish-brown | |
| or grumous matter. Collapse sets | |
| in; skin cold and clammy; | |
| frequent pulse, and respiration | |
| hurried. Delirium and convulsions | |
| end in death. Effects depend on | |
| size of dose. Well diluted, it acts | |
| on brain, spine, and heart. | |
| Post-mortem Appearances | Lining membrane of mouth and |
| fauces white, shrivelled, and easily | |
| removed. Perforation of stomach | |
| rare. The post-mortem appearances | |
| depend on dilution of acid. | |
| Fatal Dose | One drachm in a boy; in another |
| case, half an ounce. | |
| Fatal Period | Less than ten minutes. |
| Treatment | Chalk and water. Promote vomiting. |
| Magnesia, lime water, and oil. | |
| Mucilaginous drinks. |
ACETIC ACID
In the glacial form this acid acts as a corrosive, the dilute acid as an irritant. Cases have been recorded of poisoning by the glacial acid.
Symptoms.—The parts with which the acid has come in contact are softened and rendered yellowish-white in colour. The larynx is commonly affected by the acid, as it is very volatile.
Post-mortem Appearances are those of corrosive poisoning with inflammatory action in the upper air-passages.
Fatal Period is variable but rapid.
Fatal Dose.—One drachm caused death in a child, but recovery has taken place in an adult after taking six fluid ounces.
Chemical Analysis.—Separate the free acid from organic matter by distillation, if in combination it should be liberated by adding phosphoric acid. With ferric chloride and ammonia to neutralisation a red colour is produced, turned yellow by hydrochloric acid.
Treatment.—Magnesia should be given to neutralise the acid and vomiting produced. The laryngeal symptoms will require treating on general principles; tracheotomy may be necessary.
THE ALKALIES
POTASH. SODA. AMMONIA
Poisoning by the use of the alkalies is very rare. For the sake of convenience, and as the symptoms produced by the caustic preparations of soda and potash, taken in large doses, do not greatly differ, one description will do for both:
Potash is found in commerce as (1) caustic potash, either solid or in solution; (2) carbonate and bicarbonate; (3) pearl-ash and soap-lees.
Soda is found as (1) caustic soda; (2) carbonate (washing soda) and bicarbonate; (3) soap-lees, carbonate of soda mixed with caustic alkali.
General Characters.—Like the inorganic acids, the alkalies destroy the animal tissues with which they come in contact. Their action is local, no specific remote effects being produced. They are seldom, if ever, used for the purpose of homicide; the deaths caused by them are in most cases the result of accident or suicide. When injected directly into the veins of animals, the toxic action of potash and soda appears to differ, the former arresting the action of the heart in diastole, whereas the latter, according to Podocaepow and Guttman, does not, even in large doses, affect the heart or temperature—Guttman, moreover, asserting that soda has no influence upon the nerve centres, the peripheral nerves, or the muscles. It is difficult to understand how, with this asserted negative action, soda, like potash, causes death.
Symptoms.—During the act of swallowing, the patient complains of a caustic taste, accompanied with a sensation of burning in the mouth and throat, extending into the stomach. Vomiting may or may not be present; but in severe cases, when it does occur, the vomited matters may be mixed with blood. The surface of the body is cold, and bathed in a cold sweat. Purging is generally present, accompanied with intense pain and straining. The pulse is weak and quick, and the countenance anxious.
The post-mortem appearances are inflammation and softening of the mucous membrane of the mouth, gullet, and stomach, which may also be covered with chocolate-coloured or black spots. When life has been prolonged for some months the stomach may become contracted, the pyloric orifice scarcely admitting the passage of a fine probe.
Chemical Analysis.—The caustic alkalies are known from their carbonates by giving a brown precipitate with nitrate of silver; whereas their carbonates give a white, and also effervesce on the addition of an acid.
The following table will show the reaction of these alkalies with reagents:
To distinguish Caustic Potash from Caustic Soda
| Potash. | Soda. | |
|---|---|---|
| Bichloride of platinum. | A canary-coloured | No precipitate. |
| precipitate | ||
| in solutions | ||
| acidulated with | ||
| hydrochloric acid. | ||
| Strong solution of | Precipitate in granular | No precipitate. |
| tartaric acid. | white crystals. | |
| Colour given to flame. | Rose or lilac tint. | Yellow tint. |
| Neutralised with | Crystallises in long, | Crystallises in |
| nitric acid. | slender, fluted prisms. | rhombic plates. |
In Organic Mixtures.—If the mixture be strongly alkaline, filter and test as above.
Fatal Period.—From three hours to as many years.
Fatal Dose.—About half an ounce of the caustic alkali. The smallest fatal dose recorded of caustic potash is forty grains.
Treatment.—Water freely; drinks containing citric or acetic acid, vinegar, lemon juice, oil, linseed tea, and other demulcent drinks. The stomach tube should be avoided.
AMMONIA
In vapour, in solution, or solid.
Symptoms.—The vapour may cause death by producing inflammation of the larynx and lungs. The symptoms to which it gives rise are a feeling of choking, and a suspension of the power of breathing. Intense heat and pain are felt in the throat, which may remain for some time. When ammonia is swallowed in solution, the symptoms produced are not unlike those the result of the action of soda or potash, only more intense. Dr. Patterson records the history of a case of a poor man who drank about an ounce of the liquid ammonia. When seen, his lips were livid, breathing stridulous, aspect anxious, extremities cold, pulse 100; inside of mouth, tongue, fauces, as far as visible, red, raw, and fiery-looking. He died suddenly, nineteen days after the accident, of laryngeal spasm. Albuminuria occurred in one case.
The post-mortem appearances are those found in most cases of poisoning by corrosives.
Chemical Analysis.—Ammonia can be separated from organic mixture by distillation. Putrefaction must not have taken place. The vapour of ammonia is easily set free and recognised by its pungent odour. The carbonate effervesces when an acid is added to it, and gives a white precipitate with salts of lime. Dense white fumes are given off in the presence of hydrochloric acid. Nessler‘s reagent gives a reddish-brown colour or precipitate.
Fatal Period.—Death has been known to occur in four minutes, but life may be prolonged for some time, the person dying of some thoracic trouble.
Fatal Dose.—A teaspoonful of the strong solution.
Treatment.—Vinegar and water, lime-juice and oil, and leeches to the throat if the inflammatory symptoms be severe. The rest of the treatment will depend upon the symptoms present. Tracheotomy may be necessary.
CAUSTIC SALTS
CHLORIDE OF ANTIMONY
Chloride of antimony (butter of antimony) is a corrosive liquid. The colour varies from a light yellow to a dark red. Though a powerful poison, it is seldom taken for that purpose. It has been taken by mistake for ginger beer. On the addition of water, the white oxychloride is precipitated.
Symptoms.—The symptoms produced by swallowing this substance are those of corrosive poisoning. The mouth and throat are excoriated, the skin cold and clammy, and the pulse feeble and quick. Severe pain is felt in the stomach, and vomiting is incessant.
Post-mortem Appearances.—Those found after corrosive poisoning.
Chemical Analysis.—When poured into water, the chloride is precipitated; the precipitate, soluble in tartaric acid, becomes orange-red on the addition of hydrogen sulphide. The supernatant liquid will give a white precipitate with nitrate of silver, showing the presence of hydrochloric acid. The salts of bismuth are precipitated by the addition of water, but the precipitate is, unlike the antimonial, insoluble in tartaric acid, and is blackened by hydrogen sulphide.
From organic liquids, the antimony may be obtained by boiling them with tartaric acid, filtering, and then applying the tests for antimony.
Treatment.—Milk, magnesia, and infusions containing tannin.
CHLORIDE OF ZINC
This substance is a powerful corrosive. It is employed as a disinfectant, and is sold to the public under the name of “Sir W. Burnett‘s Fluid.” This preparation, which is a strong solution of the chloride of zinc, has caused death by being mistaken for “fluid magnesia,” for “pale ale,” and in one case, on board one of the American steamers, for “mineral water.” Chloride of zinc is also used in the treatment of cancer and other tumours as an external application.
Symptoms.—The symptoms come on immediately after the poison is swallowed. Chloride of zinc acts as a powerful corrosive, accompanied with all the symptoms which have been before described when speaking under the head of corrosive poisons. The nervous system is also powerfully affected.
Post-mortem Appearances.—Those of corrosive poisoning in its most violent form. The mouth, throat, stomach, and intestines are often found hardened, white, opaque, and corrugated.
Chemical Analysis.—Ammonium sulphide gives a white precipitate, which is insoluble in caustic alkalies. Hydrogen sulphide gives a white precipitate in neutral solutions, but no precipitate when the free mineral acids are present. Potassium ferrocyanide gives a white precipitate. Test for chlorine with nitrate of silver.
Treatment.—White of eggs, emetics, followed by demulcent drinks.
CHLORIDES OF TIN
This metal requires but little notice; but the two chlorides—protochloride and the perchloride—form a mixture used in the arts, and known as Dyer‘s Mixture. They act as irritant poisons, but are seldom used as such.
NITRATE OF SILVER
The only preparation of silver requiring notice is the nitrate—lunar caustic, or lapis infernalis. It acts as a powerful corrosive. If administered for some time in small doses it is deposited in the skin, which acquires a permanent dark colour. It does not appear to be eliminated by the urine, and has been discovered in the liver five months after its administration was discontinued.
The symptoms come on immediately, the vomited matters becoming blackened on exposure to light. The dark spots on the skin will also help to point to the nature of the poison. A dose of salt and water may be given by way of treatment.
VULNERANT
GLASS, ENAMEL, AND NEEDLES
None of the above can be considered as poisons; but should they be taken, they give rise in most cases to irritation of the stomach and bowels. Pins and needles have been swallowed without doing much harm. Mixing ground-glass in food is a favourite mode of killing adopted by the West Indian negroes.