Memoranda on Poisons Part 6

a.r.s.enic is not a poison that acc.u.mulates in the system, but is slowly eliminated from it especially by the kidneys, but partly also by the bile.

The local application of a.r.s.enic to the mucous membranes, to wounds, or to surfaces deprived of their cuticle, produces const.i.tutional effects similar to those just described. The only difference is that the symptoms show themselves more slowly. Not a few lives have been sacrificed from the application by ignorant quacks of a mixture of a.r.s.enious acid, realgar, and oxide of iron to ulcerating cancers.

Cases of compound poisoning have been met with. When a.r.s.enic is taken mixed with opium, the symptoms produced by the former are masked.

_Post-mortem Appearances._-a.r.s.enic appears to exercise a specific influence over the alimentary ca.n.a.l, and more especially over the stomach; for in whatever manner it may have been introduced into the system, it is to this organ that we must look for its effects. These effects consist in the signs of acute inflammation commencing in this viscus, and often extending along the duodenum, small intestines, and colon. In acute cases the stomach is the viscus most affected; but in chronic cases the whole alimentary ca.n.a.l is found inflamed and ulcerated, particularly the duodenum and r.e.c.t.u.m. When death has occurred within five hours of taking the poison, the stomach has been found intensely inflamed in an adult; while the same result was witnessed in a child who died at the end of two hours. The stomach often contains a dark grumous fluid, occasionally tinged with blood. On removing the contents the mucous membrane is seen red and inflamed, the inflammation being most intense around certain spots. On examining these spots, particles of a.r.s.enic will probably be found adhering to the walls of the stomach and surrounded by a zone of inflammatory redness.

Sometimes also blood is effused into the visceral walls, giving rise to an appearance resembling gangrene. Ulceration of any of the coats of the stomach is rare, and perforation is still more so.

In a few exceptional cases there has been no appearance of inflammation in the stomach or bowels.

Putrefaction of the body is said to be remarkably r.e.t.a.r.ded after death from a.r.s.enic.

_Treatment._-The first object must be to expel the poison from the stomach, for which purpose the stomach-pump may be advantageously employed, or emetics of sulphate of zinc, mustard, or ipecacuan administered, unless vomiting is already present. The sickness must be promoted by the free use of alb.u.minous or mucilaginous diluents. Raw eggs beaten up in milk are particularly useful, as is likewise a mixture of alb.u.men, milk, and limewater. Taylor advises equal parts of oil and limewater, for the oil invests the poison, and the lime renders it less soluble. A large dose of castor oil (?j to ?ij) may be given, to carry off any of the poison which may have pa.s.sed into the intestines, as soon as sickness has subsided. Animal charcoal, calcined magnesia, &c., when taken in large quant.i.ties, may be of service by enveloping the a.r.s.enic, and preventing its contact with the mucous membrane of the stomach; but oil or milk will act more efficiently in this manner. The hydrated peroxide of iron[B] should be administered moist, and in large doses, after the stomach-pump has been used; or indeed, mixed with water, it may be first introduced and then expelled, thus washing out the stomach by means of the stomach-pump. This is the most efficient antidote known.

The subsequent treatment must be conducted on general principles, according to the severity of the symptoms; but the great depression of the nervous and vascular systems must not be overlooked in combating any inflammatory action. Henbane or opium, in many instances combined with stimulants, ice internally, and hot fomentations externally, will frequently be found of great service.

_Tests._-In its _solid state_ a.r.s.enious acid may be known by the following properties. Heated on platinum foil or on the point of a penknife, it produces a white smoke and is entirely volatilized. If some of the powder be heated in a small test tube, it will be sublimed, and small octahedral crystals, visible to the naked eye or by a lens, obtained. If a.r.s.enious acid be mixed with freshly-burnt powdered charcoal, and heated in a small test tube, a ring of shining metallic a.r.s.enic of a grey color will be found on the cool portion of the tube, and an odor of garlic is perceptible. If this deposit be driven about from place to place it will gradually become oxidized, and octahedral crystals of a.r.s.enious acid formed. Further, if the tube be divided and the part containing the a.r.s.enious acid be washed out with distilled water, the liquid tests may be applied to the solution. This is called the Reduction test. It is very delicate, detecting according to Christison, the 300th part of a grain.

_In solution_, this substance may be detected by what are called the liquid tests. A solution of a.r.s.enic in water is colorless, almost tasteless, and has a very slightly acid reaction. If a few drops be evaporated on a gla.s.s slide and examined by the microscope, numerous minute and mostly imperfect octahedral crystals, or an amorphous deposit, will be seen, presenting triangular surfaces by reflected light.

1. The _ammonio-nitrate of silver_ (prepared by adding a few drops of liquor ammoniae to a solution of nitrate of silver, till the brown oxide of silver at first precipitated is nearly redissolved) throws down with a.r.s.enious acid a rich yellow deposit of a.r.s.enite of silver.

2. The _ammonio-sulphate of copper_ (formed by adding liquor ammoniae to a solution of sulphate of copper till the bluish-white oxide of copper is almost redissolved) produces a pale green precipitate, a.r.s.enite of copper, or Scheele's green. Care must be taken not to add too much of the test in the first instance, otherwise its blue may overpower the green of the precipitate.

3. _Sulphuretted hydrogen water_ precipitates a yellow deposit of sulphide of a.r.s.enic. It is better, however, to use pure and well-washed sulphuretted hydrogen generated in the usual manner. Care must be taken that the liquid is not alkaline, or no precipitate will be produced, even though a.r.s.enic be present. For this reason yellow sulphide of ammonium will not precipitate a.r.s.enic until acidulated with pure hydrochloric or some such acid. The precipitate should be collected, carefully washed, and dried. It should then be mixed with black flux or dry ferrocyanide of pota.s.sium and reduced, as already described.

These tests are so delicate, especially the first, that they will detect the 8000th part of a grain of a.r.s.enic in solution; they should be employed successively. There are several other processes which require to be noticed, namely, Marsh's process, the process known as Reinsch's process, Fresenius's process, and the Destillation process.

_Marsh's Test or Process._-This process is founded on the decomposition of a.r.s.enious acid by nascent hydrogen, and the formation of a.r.s.enuretted hydrogen gas, which possesses the following properties: It burns with a bluish-white flame, and white smoke (a.r.s.enious acid), possessing a slight garlic odor. If a piece of gla.s.s or porcelain be held in the flame a blackish metallic stain will be deposited upon it, consisting of metallic a.r.s.enic. This stain might be confounded with one produced by antimony under similar circ.u.mstances. But the antimonuretted hydrogen gas does not burn with the odor of the a.r.s.enuretted hydrogen; while the antimonial stain is sooty, and has not a metallic l.u.s.tre. The a.r.s.enical stain is further readily dissolved by a solution of chloride of lime (bleaching powder), whilst the antimonial stain is not affected. To the stain may be added a few drops of strong nitric acid; it will dissolve the a.r.s.enic; if this be allowed to evaporate, and the acid be neutralized, a few drops of nitrate of silver solution will give a brick-red precipitate of a.r.s.eniate of silver.

Marsh's test is thus accomplished: a flask furnished with a cork through which pa.s.s a funnel and a long bent tube drawn to a point, is prepared so that the funnel reaches almost to its bottom. Several pieces of pure zinc are introduced, and then some sulphuric acid is poured through the funnel. In this way hydrogen gas is produced and escapes by the bent tube. When all the air has been expelled the gas should be ignited as it escapes, and a piece of cool porcelain held over the flame. If there be no deposit it is plain that neither the zinc nor the sulphuric acid, contains a.r.s.enic. A portion of the suspected fluid is next introduced into the flask by the funnel, and the issuing gas again tested. Should a stain giving the characters alluded to above be produced, the fluid contains a.r.s.enic in some form or other.

_Reinsch's Process._-The suspected liquid is boiled with from one-sixth to one-eighth of its bulk of pure hydrochloric acid, and a bright slip of copper introduced. If a.r.s.enic be present the copper will be coated with it in the form of an iron-grey deposit. Next after removing the copper, washing it with distilled water, and drying it between folds of blotting paper, cut it into slips, and introduce it into a reduction-tube and apply heat; a.r.s.enious acid will be sublimed and deposited on the sides of the tube, in the form of minute octahedral crystals. These may be dissolved in water and tested in the usual way.

Before resorting to this test, the acid must be examined to make sure of its purity. This is easily effected by boiling the copper with a mixture of the hydrochloric acid and distilled water before adding the suspected liquid. In conducting the a.n.a.lysis in the case of Smethurst (Cent.

Crim. Court, Aug. 1859) Taylor and Odling found that all the varieties of copper in common use for Reinsch's process contained a.r.s.enic. A copper of ascertained purity must therefore be used.

_a.r.s.enic in Organic Matters._-The following process, which has been introduced by Dr. Taylor, is a very convenient one. The suspected matters are to be thoroughly dried in a water-bath or otherwise, taking care not to use too great a heat. They are then to be introduced into a flask fitted with a long bent tube; to the dried material is to be added a quant.i.ty of strong hydrochloric acid, proved free from a.r.s.enic, sufficient to drench it, and the whole allowed to digest for some hours.

At the end of that time heat is to be applied to the flask by means of a sand-bath, and a receiver fitted to the bent tube. The receiver should contain a little water, and both it and the bent tube should be kept cool. As distillation goes on the a.r.s.enic pa.s.ses over in the form of chloride of a.r.s.enic, and is collected in the receiver beyond. A second portion of hydrochloric acid may be used to remove any last traces of a.r.s.enic in the organic material. The a.r.s.enic may be recovered from the chloride by boiling with pure polished copper, as in Reinsch's process.

The process of Fresenius and Von Babo given at page 31 is especially adapted for the recovery of a.r.s.enic from organic admixture.

Several cases of poisoning by a.r.s.enuretted hydrogen are on record, some proving fatal.

CHAPTER XVI.

ANTIMONIAL COMPOUNDS.

In its metallic state antimony is not regarded as poisonous. Two of its preparations, however, claim attention; namely, tartar emetic, and chloride of antimony.

TARTAR EMETIC (_Tartrated_ or _Tartarised Antimony_, _Pota.s.sio-Tartrate of Antimony_, _Tartar Emetic_).-Since the trials of Palmer, Dove, Smethurst, and Pritchard, poisoning by this compound has attracted much attention. In large doses it has been administered without any serious result, a circ.u.mstance which may be accounted for by the prompt.i.tude with which it excites vomiting and purging. Given in small doses, frequently repeated, the effects of tartar emetic may be made to simulate, in some degree, those due to natural disease.

Three quarters of a grain killed a child; and a dose of two grains has destroyed an adult, under circ.u.mstances which favored its action. Dr.

Taylor says that from ten to twenty grains taken at once might prove fatal to an adult; while in divided doses a smaller quant.i.ty might suffice. It is plain, therefore, that the quant.i.ty necessary to cause death must vary with the condition of the patient.

_Symptoms._-In acute poisoning by this agent there is a metallic taste, nausea, and violent vomiting, burning heat with pain in the stomach, and purging. Difficulty in swallowing, thirst, cramps, cold perspiration, and great debility soon set in. Should the case terminate fatally, death may be preceded by giddiness, insensibility, difficult respiration, utter prostration, with violent spasms, tonic or clonic; but even when matters appear to be most critical, symptoms of improvement are often manifested, and recovery gradually follows.

The effects of _chronic_ poisoning are, constant nausea, frequent attacks of vomiting and purging, a loathing for food, a weak frequent pulse, loss of muscular power, cold clammy sweats and fatal exhaustion.

The symptoms are of course aggravated after each administration of the poison, whether given in food or medicine.

Tartar emetic ointment applied to the skin produces a pustular eruption like that of smallpox; while, if much be absorbed, there will be nausea, sickness, &c. Sometimes this same eruption appears in the throat and on the skin after swallowing a large dose.

_Post-mortem Appearances._-The most common are inflammation of the throat, stomach, and intestines. Sometimes the mucous membrane of the stomach is softened and infiltrated with blood. The caec.u.m and large intestine are also inflamed, especially if life has been prolonged after the dose, as in chronic poisoning. The brain and lungs have been found congested.

_Treatment._-Vomiting should be encouraged by warm greasy water, milk, &c. Liquids containing tannin, as tea without milk or sugar, decoction of oak bark, &c., must be freely given. Cinchona bark in tincture or powder may be advantageously prescribed. Afterwards opiates may be administered.

_Tests._-Tartar emetic is soluble in water but not in alcohol.

In solution tartar emetic may be thus detected:

1. A drop evaporated on a gla.s.s slide leaves microscopic crystals, either tetrahedra or cubes, with the edges bevelled off.

2. The solution may further be proved to contain antimony by pa.s.sing through it sulphuretted hydrogen or adding to it sulphide of ammonium, either of which throws down an orange-red precipitate of sulphide of antimony. This precipitate is soluble in strong hydrochloric acid, which being diluted, throws down a white precipitate.

3. The three dilute mineral acids (nitric is best) throw down a white precipitate with tartar emetic, which is soluble in excess of the acid used or in tartaric acid.

The metal may be separated from organic substances by Marsh's or Reinsch's process.

CHLORIDE OF ANTIMONY (_Terchloride_ or _b.u.t.ter of Antimony_) is a powerfully corrosive liquid. It produces violent inflammation and corrosion of the whole intestinal ca.n.a.l; occasionally also drowsiness, as from the use of a narcotic.

Dr. Taylor has collected the histories of four cases of poisoning by b.u.t.ter of antimony, three of which recovered. The fourth, in which a gentleman took from two to three ounces, proved fatal in ten hours and a half, after producing great prostration, nausea, violent griping pain, and tenesmus, followed by a tendency to sleep. On inspection, the whole of the inside of the alimentary ca.n.a.l was blackened, as if it had been charred; there was but little mucous membrane remaining, and the parts were much softened.

_Treatment._-Magnesia must be administered in milk, together with the remedies recommended in poisoning by tartar emetic.

CHAPTER XVII.

MERCURY AND ITS COMPOUNDS.

Of the preparations of mercury, corrosive sublimate is the most important to the toxicologist; for although they all possess in a greater or less degree poisonous properties, yet the instances in which the other compounds have been used to destroy life are extremely rare.

The treatment in all cases must be the same. It is worthy of remark that mercury, whilst in the metallic state, is dest.i.tute of injurious properties, but if oxidized or otherwise rendered fit for absorption, it may give rise to dangerous symptoms. Thus, workers in mercurial mines suffer much, as did those who were employed in silvering looking-gla.s.ses by the old process. Large doses (from half a pound to two pounds) have been given in obstinate cases of constipation, intussusception, &c., without any remarkable effect.