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 destitute 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-glasses 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.
Corrosive Sublimate(Oxymuriate of Mercury,Chloride of Mercury,Bichloride of Mercury).—This preparation of Mercury, which, more strictly speaking, belongs, like the chlorides of zinc and antimony, to the class Corrosives, is usually met with in the form of imperfect crystalline masses, or as a white powder. It has an acrid, coppery taste, so powerful that but little could be swallowed without the individual becoming aware of it. It is very soluble in water. Three grains is the smallest quantity that has been known to prove fatal; and from this to five grains may probably be stated as the average dose necessary to destroy life. Recovery has taken place after as much as eighty grains had been swallowed.Death has occurred in less than half an hour; while, in some instances, life has been maintained until the sixth day, and in one instance (where between three and four scruples had been swallowed) until the twelfth day. It is probable that the average duration of fatal cases is from twenty-four to thirty-six hours.
Symptoms.—In the majority of cases the symptoms commence immediately, with an acrid metallic taste, often described as coppery, and a sense of constriction and burning heat in the throat and stomach. The burning pain gradually extends over the abdomen, and is much increased by pressure. There is nausea, with vomiting of the contents of the stomach. These matters are sometimes mixed with blood and stringy masses of mucus. The sickness is accompanied by diarrhœa or dysentery, swelling of the abdomen, and increased pain. The countenance becomes flushed and often swollen, though it is occasionally pallid and anxious; the lips and tongue get white and shrivelled; there is frequently some dyspnœa, while the pulse is small, or wiry and frequent; and death is preceded by faintness, cramps, insensibility, or convulsions.
Should these effects not prove rapidly fatal, the pain will gradually become lessened, though attacks of colic and nausea may come on at intervals for several days. Often the secretion of urine is almost, or even quite, suppressed. After a time there are symptoms of hectic fever, with much depression. The gums and salivary glands also become swollen, there is a coppery taste in the mouth, the breath is very fœtid, and there is severe ptyalism or salivation. This latter effect is the most prominent feature in thechronicform of poisoning, where small and frequently-repeated doseshave been given: it often proceeds to such an extent as to cause death, when the patient would otherwise probably recover.
It must not be forgotten that salivation sometimes arises where no mercurial of any kind has been given. Thus arsenic, bismuth, lead, iodide of potassium, opium, &c., may induce it in some very peculiar constitutions. Small medicinal doses (as a few grains of calomel) may also excite it in certain susceptible individuals; and especially in persons suffering from renal disease. It may also occur spontaneously, as in stomatitis or inflammation of the mouth; and very troublesome examples of it may occur in pregnant women.
It is strange that neither in acute nor chronic mercurial poisoning do we observe any marked loss of muscular power. Yet workers in quicksilver (owing to the absorption of the fumes of mercury during respiration) are very apt to suffer from a peculiar kind of paralysis; which commences with inability to direct the hands and arms, and goes on to a shaking or trembling of all parts of the body.
Post-mortem Appearances.—The appearances produced by corrosive sublimate are confined chiefly to the digestive canal. The mucous membrane of the mouth, fauces, and œsophagus is softened and of a whitish or bluish-grey color. The stomach also presents marks of violent inflammation; beneath the mucous membrane numerous patches of extravasated blood are seen, and frequently corrosion or ulceration has been found. The large and small intestines, the peritoneum, and especially the urinary organs, often appear inflamed. In many instances the bladder has been much contracted.
Treatment.—This must consist in the removal ofthe poison and the administration of antidotes. Vomiting is best promoted by administering copious draughts of fluids containing albumen: but if necessary ipecacuan may be given. The white and the yolk of raw eggs with milk should be abundantly administered. Gluten has been much recommended, and may readily be prepared by washing flour in a muslin bag under a stream of water; but on an emergency it will be best to exhibit the flour at once, made into a paste with milk or water. The free use of demulcent drinks, milk, and ice will be very grateful to the patient’s feelings. Gargles of alum or borax do some good. Opiates may be given in small doses, if there be much pain, and we should allow only a milk or farinaceous diet. Sucking chlorate of potash has been recommended to check the salivation. The most useful remedy, however, is the iodide of potassium; for this salt destroys the compounds formed by the union of mercury with certain of the tissues, and eliminates the poison through the kidneys.
Tests.—Corrosive sublimate is completely volatilized by heat.
1. Liquor potassæ added to its solution gives a yellow precipitate. This precipitate, if washed, dried, and heated in a test tube, gives a ring of metallic mercury in the form of globules in the cool part of the tube. In like fashion corrosive sublimate itself may be reduced and volatilized if heated with black flux.
2. On adding a solution of iodide of potassium to a small quantity of the solution, a bright scarlet precipitate, soluble in excess of iodide of potassium, is produced.
3. If a drop or two of a solution of corrosive sublimate, slightly acidulated with hydrochloricacid, be placed on a sovereign, and the solution and the gold be touched with a piece of zinc or an iron key, the mercury will be deposited as a bright silvery stain on the gold.
Calomel(SubchlorideorChloride of Mercury) is a heavy white powder, which is usually regarded as a safe medicine. Yet, in some peculiar constitutions, it has caused excessive salivation and death, even though only a few grains have been given. In large doses it may be regarded as an irritant poison. It is distinguished from corrosive sublimate by forming a black precipitate with caustic potash and by its insolubility in water.
Ammonio Chloride of Mercury(White Precipitate).—This substance is a chalky looking powder, containing about eighty per cent. of mercury. It produces vomiting, purging, great pain in the stomach, cramps, and convulsions. Out of fourteen cases, collected by Dr. Taylor, in which from a few to forty grains were taken, only two proved fatal.
The remaining preparations of mercury, which in rare instances have been used as poisons, are theRed Oxide of Mercury(red precipitate); theRed Sulphuret of Mercury(cinnabar or vermilion); theCyanide of Mercury; theNitrates of Mercury; andTurpeth Mineral.
Mercury may be separated from organic admixture by Reinsch’s method.
Lead, in its metallic state, is not injurious. It is, however, really acted on by acids, exposure tothe atmosphere, &c., and converted into carbonate of lead. The chief compounds of this metal which have been found to produce poisonous effects are the acetate, subacetate, and the carbonate.
Acetate of Lead(Sugar of Lead).—This is sold as a glistening white powder, or in the form of crystalline masses resembling loaf sugar. It is more frequently used as a poison than either of the other compounds. It is very soluble in water and has a sweetish metallic taste. Three or four instances are recorded in which recovery has taken place after an ounce of this substance has been taken in solution.
Mr. Bancks, of Stourbridge, has reported the particulars of a series of cases of poisoning by the acetate of lead (Lancet, 5th May, 1849). It appears that thirty pounds of this substance were accidentally mixed at the miller’s with eighty sacks of flour. This was made into bread, from eating which 500 persons suffered severely. The chief symptoms were a sense of constriction in the throat and at the pit of the stomach, crampy pains round the navel, stiffness of the abdominal muscles, paralysis of the lower extremities, constipation, scanty urine, and the formation of a deep blue line round the gums. Although in many cases there was great prostration with other alarming symptoms, yet under the use of purgatives all recovered. It was noticed that after a temporary convalescence many of the symptoms returned in an aggravated form without any apparent cause. Sometimes there has been vomiting and purging, and there is great prostration, with cramps and convulsions.
Post-mortem Appearances.—They are not usually very distinct. The stomach and intestines have been found inflamed, and the surface of the formersoftened and, in the case of animals, corroded. There may be no characteristic signs in chronic poisoning.
Subacetate of Lead(Goulard’s Extract).—This substance is known to have proved fatal in three or four instances, after having caused great agony. It is a more powerful poison than the acetate. It is found in the shops as a whitish-colored liquid.
Carbonate of Lead(White Lead,Ceruse,&c.).—This is sold in heavy white masses, looking like chalk. It is readily acted on by acids, but is very insoluble in water.
Dr. Snow has reported an instance in which a child ate a portion, about the size of a marble, mixed up with oil; it died on the fourth day. Carbonate of lead derives its greatest interest from the chronic form of poisoning which it produces among white lead manufacturers, painters, &c., known as “the painters’ colic,” which too often terminates in “lead palsy.” In these instances the lead finds its way into the system by absorption from the digestive canal, the lungs, or the skin; producing its characteristic effects when a sufficient amount has been absorbed. It is this salt which is formed by the action of air and water upon lead.
The other preparations of this metal do not require any separate notice.
Treatment.—The sulphates of soda or magnesia should be freely given dissolved in water. Milk, or milk and eggs will be useful. If vomiting is absent, an emetic of sulphate of zinc should be administered, or the stomach-pump may be advantageously employed.
For a chemical antidote in poisoning by carbonate of lead Dr. Taylor recommends a mixture of vinegar and sulphate of magnesia.
Tests.—The presence of a salt of lead in solution may be thus ascertained:—1. On passing sulphuretted hydrogen through it, or on adding a few drops of sulphide of ammonium, a black precipitate is given. 2. A white precipitate results from the use of liquor potassæ or liquor ammoniæ. 3. Dilute sulphuric acid gives a similar precipitate, which is insoluble in nitric acid. 4. Iodide of potassium affords a bright yellow deposit (iodide of lead).
Chronic Lead Poisoning.—The chronic and insidious effects produced by lead upon the constitution are deserving of careful attention. Water impregnated with this metal in its passage through lead pipes or cisterns, acquires poisonous properties. Lead-pigments are sometimes improperly used to color cheese, lozenges, snuff, &c. The endemic colic of Devonshire was due to the absorption of lead contained in cider, which had been made in leaden vessels; and in the wine district of Poictou attacks of colic were so common, from the impregnation of wine with this metal, that we still speak of “colica Pictonum.”
The pernicious influence of lead is manifested among those engaged in the manufacture or use of lead compounds, especially painters, lead smelters, plumbers, color grinders, shot manufacturers, workers in sugar of lead, potters, compositors, enamellers of cards, &c. These artisans should be advised to prevent disease by great cleanliness, by avoiding intoxicating liquors, and by drinking freely of sulphuric acid lemonade. The substitution of moist for dry grinding has proved useful.
The most prominentsymptomsof chronic poisoning by lead are as follows: A blue line aroundthe gums, and the liability of the latter to bleed from any slight cause; emaciation, a pallid tint of the complexion, poorness of blood, and a feeble quick pulse; obstinate constipation, with attacks of colic relieved by pressure; diminution of the renal secretion and rheumatic pains; afterwards comes weakness of the hands, wrists, and arms, ending in paralysis of the extensors, or “dropped wrists,” creeping up the arms.
Thetreatmentof these cases must consist in the first instance in the use of purgatives; none being better than sulphate of magnesia with the dilute sulphuric acid. But the remedy of all others is the iodide of potassium, in five or ten grain doses thrice daily; this agent acting most beneficially when employed in conjunction with galvanism to the paralysed limbs.
Poisoning with the salts of copper is of comparatively rare occurrence; when it happens, it is generally the result of accident. The metal itself is not poisonous, but the action of the gastric juice may produce a very deleterious salt. Copper coins, when swallowed, sometimes on this account prove mischievous; though usually any ill effects which ensue are due to their mechanical action. Salts of copper have been accidentally introduced into the system by means of food which has been cooked in copper saucers. The most importantsubstances of this class to the toxicologist are the following:
Sulphate of Copper(Blue Vitriol).—Blue-stone is met with in large crystals, which are very soluble in water and possess an acrid metallic taste. In doses of half an ounce it acts as a powerful irritant. It has been administered to procure abortion. In the case of a child sixteen months old, who sucked some pieces of blue-stone with which she was playing, death occurred in four hours.
Subacetate of Copper(Verdigris).—This preparation is met with in masses, or in the form of a greenish powder. It possesses a powerful astringent metallic taste. It is often produced by allowing substances to stand in coppers. It has proved fatal in half ounce doses.
Arsenite of Copper(Mineral Green).—The effects of this salt have been already referred to.
Symptoms.—Pain in the epigastrium, gradually extending over the abdomen, violent vomiting—the vomited matters being of a blue or green color—and diarrhœa, are the symptoms which set in the most speedily. Then there is usually dyspnœa, great depression, coldness of the extremities, headache with giddiness, and slight tetanic convulsions. Sometimes there is suppression of urine. Jaundice very frequently occurs—a symptom the more important, as it is rarely met with in most other forms of poisoning. Occasionally stupor, coma, and paralysis supervene. Should death ensue, it may occur within a few hours, or not for several days.
The salts of copper taken in very small doses, for several days, give rise to a metallic taste in the mouth, thirst, debility, cramps and colicky pains, with symptoms of dysentery. In some instances there has been found retraction of the gums withthe formation of a purple line, very distinct from the blue mark due to lead.
Post-mortem Appearances.—Evidences of inflammation are usually found in the stomach and intestines, the mucous membrane being often ulcerated and of a blue-green color. Particles of the poison may sometimes be found adhering to the coats of the bowel. Perforation of the intestines has occurred.
Treatment.—Vomiting sets in spontaneously, and is to be encouraged by the use of warm water. The stomach pump will rarely be needed. The only effectual antidote is albumen. The whites and yolks of several eggs should therefore be given, followed immediately by milk or mucilaginous drinks.
Tests.—Solutions of the sulphate and nitrate of copper are blue; the chloride is green. The salts of copper may be thus identified:
1. A polished knife or needle introduced into the solution is soon covered with a coating of copper.
2. Ammonia produces with a salt of copper a bluish precipitate, readily soluble in excess of ammonia, and forming a splendid blue solution.
3. Ferrocyanide of potassium gives a claret-colored gelatinous precipitate, if the copper be abundant; otherwise the deposit is of a light brown.
4. Sulphuretted hydrogen gas yields a deep-brown precipitate.
5. A few drops of the copper solution are to be placed on platinum foil, and slightly acidulated; on touching the foil, through the solution, with a strip of zinc, metallic copper is deposited on the patinum.
Laburnum(Cytisus laburnum).—Every portion of this plant is poisonous. The seeds are frequently eaten by children, and give rise to vomiting and purging, with dilatation of the pupils, rigors, rigid limbs, &c.
Œnanthe crocata,Phellandrinum aquaticum,Æthusa Cynapium,&c., strictly speaking, belong to this group.
Black Hellebore(Helleborus niger) orChristmas Rose, grows in shady woods, and bears a large flower in January. The leaves and root when eaten give rise to abdominal pain, vomiting and purging, vertigo, cold sweats, and collapse, resembling that of malignant cholera. An infusion of this plant is sometimes administered by quacks to destroy intestinal worms. It has proved fatal to children under these circumstances.
Several other substances variously grouped for the sake of convenience should come under this heading.
This poison is well known, and is usually administered in the form of powder or tincture. Of theformer, twenty-four grains have destroyed life; of the latter, one ounce. This poison has been employed as an aphrodisiac and to induce abortion, by persons ignorant of its dangerous effects. This is, perhaps, the most frequent cause of poisoning by cantharides. Applied externally it has proved fatal, as in the case of a girl affected with scabies, who anointed the whole of her body with cantharides ointment in mistake for that of sulphur. She died in five days, after suffering from the symptoms of poisoning by cantharides.
It produces an acrid taste, vomiting, purging, burning heat in the stomach, pain in the loins, severe strangury, bloody urine, and priapism. Then there is faintness with giddiness, the limbs become rigid, and delirium with convulsions precede death. Sometimes the matters ejected from the stomach or passed in the stools contain shining golden or green particles, the remains of the wing cases of the beetles, which constitute the drug, readily seen with a lens, or even with the naked eye.
After death, marks of inflammation are found in the alimentary canal, kidneys and bladder, and the genital organs.
Tests.—The detection of Spanish flies, if taken solid, depends mainly on the presence of the shining particles already alluded to, in the stomach, or in the vomited matters. To make their nature certain, however, an extract of the suspected materials should be prepared and treated repeatedly with chloroform or ether. This fluid is to be allowed to evaporate till only a few drops are left, which may be applied on lint to some portion of the body where the skin is fine, as the fore arm, the part being covered by a bit of isinglass plaster,or goldbeaters’ skin. The vesication produced is the test of the presence of cantharides.
No antidote is known. Vomiting must be excited or encouraged; and linseed tea, and gum water, or gruel copiously administered. The warm bath will afford great relief. Oil must be avoided, on account of its being a solvent of the active principle (cantharidine) of this poison.
Opiumis the inspissated juice of the unripe capsules of thePapaver somniferum, or white poppy, and is a very complex substance. Its principal properties, however, are due to the presence ofmorphia, as meconate of morphia; but others of its constituent substances undoubtedly modify its action.
It is sometimes used as a poison in its crude state, but more frequently in solution in alcohol, forming tincture of opium, or laudanum. Unfortunately, opium is the powerful ingredient of most soothing syrups for children, to whom opium is at all times especially dangerous; and many who do not die from its direct effects, do from the wasting indirectly produced.
Of domestic quieting physic the chief preparations are Godfrey’s Cordial, supposed to consist of one grain of opium in two ounces; and Dalby’s Carminative, which is one-fourth weaker.
The smallest quantity oflaudanumwhich is known to have proved fatal to an adult is twodrachms, from which death occurred within twelve hours. The exact quantity taken was, however, doubtful. Two grains and a half of theextract, a quantity said to be equal to four grains of crude opium, have produced a similar result. Much larger doses are, however, taken with impunity on many occasions, more especially by those habituated to the use of this drug, who remain almost unaffected by surprisingly large quantities. De Quincey, the English opium-eater, once found in a pirated edition of “Buchan’s Domestic Medicine,” a caution against taking more than “twenty-fiveounces” of laudanum at one dose. He says that he always bore thisexcellentadvice in mind; and it does not appear that he ever took more than sixteen ounces of the tincture of opium as his daily allowance. In certain diseases, patients quite unaccustomed to the use of sedatives can take excessive amounts without narcotism being produced. In some cases of tetanus, for example, upwards of four ounces of laudanum have been given daily for a week, without any marked effect.
On the other hand, it must not be forgotten that not a few individuals are unable to take even one-third of a grain without being narcotised. Young children are particularly susceptible of its effects; the tenth and twelfth parts of a grain having respectively proved fatal to infants two and five days old. Dr. Edward Smith has even recorded the case of an infant seven days old, who died comatose eighteen hours after having had administered to it about the twelfth of a grain of opium, or the quantity contained in one drop of laudanum.[C]The smallest fatal dose for a child onrecord is one of paregoric elixir equivalent to about one-ninetiethof a grain of opium. On the other hand, they sometimes recover from very large doses indeed.
The duration of a fatal case is generally from seven to twelve hours. The shortest period recorded is three-quarters of an hour; the longest, twenty-four hours. If the patient survives twelve hours there is good hope of recovery.
The quantity ofMorphiafound in opium varies from two to ten per cent. The chief salts of this alkaloid are theacetate, thehydrochlorate, and thesulphate, all being very energetic poisons. They cause symptoms similar to those about to be described as produced by opium. But, in addition, there has been especially noticed great itching of the skin, convulsive twitchings of the muscles of the face and limbs, and occasionally tetanus. Small doses of any of the salts of morphia may cause death. In a delicate woman half a grain is supposed to have proved fatal; in several instances one grain has proved fatal; and certainly a dose of two grains might kill a healthy adult unaccustomed to opiates. Nevertheless, under the influence of custom, large quantities may be taken. A young lady, who has long been under notice, has for the last three years taken daily fifteen grains of the hydrochlorate of morphia, without obtaining more than two or three hours’ sleep from it; while for many days in succession, when suffering much pain, she increases the quantity to one scruple. From attempts to diminish the dose,made without the patient’s knowledge, only mischief has resulted.
Others of the opium alkaloids are poisonous; but instances of poisoning by their means have not occurred, except one doubtful instance of poisoning by narcotine, recorded by Sonnenschein.
Symptoms.—When a large dose of opium or its tincture has been taken the symptoms usually manifest themselves in about twenty or thirty minutes. They commence with giddiness, drowsiness, and stupor; then ensues insensibility. The patient appears as if in a sound sleep, from which he can be roused by a loud noise, &c., although he quickly relapses. As the poisoning progresses the breathing becomes slow and stertorous, the pulse weak and feeble, and the countenance livid. The eyes are closed, while the pupils are generally contracted, often almost to the size of a pin’s point, and insensible to the stimulus of light. In some instances the skin is cold and livid, in others it is bathed in sweat. So also the countenance may be either ghastly or placid, the pupils may even be dilated, and the pulse may be unaffected, or so small and frequent as to be scarcely appreciable. Vomiting sometimes occurs, with slight reaction, so that hopes of recovery are entertained. But frequently there is a relapse, the comatose state returns, and death quickly follows, occasionally preceded by convulsions.
The possibility of rousing a patient during the earlier portion of the progress of these symptoms will assist in diagnosing the effects of poisoning by opium from those due to apoplexy, epilepsy, &c. The contracted condition of the pupil will also assist; but it must not be forgotten that in lesion of the pons Varolii the pupils are also contracted. When permanent recovery ensues it is complete;but it is usually preceded for a day or two by severe nausea, a sense of weariness, constipation, and headache.
The habitual use of opium is most injurious. Dr. Oppenheim, in his description of the state of medicine in Turkey, tells us that persons seldom attain the age of forty who have begun the practice early. The opium-eater may be known by his attenuated body, withered yellow countenance, stooping posture, and glassy, sunken eyes. He has no appetite, his bodily powers are destroyed, and he is obliged continually to increase the dose of his “grief-assuaging remedy” to obtain the wished-for effect.
Post-mortem appearances.—The appearances in acute poisoning by opium are not very characteristic. The most prominent are, great turgescence of the vessels of the brain, with effusion of serum into the ventricles and at the base. The turgid condition of the vessels often continues down the spinal cord, &c. The lungs are usually gorged with fluid blood, and the skin is of a livid hue.
Treatment.—The first object is to remove all the poison from the stomach, and this cannot be effected in any way so well as by the stomach-pump. In the absence of this instrument, emetics of half a drachm of sulphate of zinc, or a tablespoonful of mustard, must be employed. The patient at the same time is to be prevented as far as possible from going to sleep. When the stomach has been thoroughly emptied, every means must be adopted to keep the patient roused. This is to be effected by dashing cold water over his head and chest, walking him up and down or shaking him between two attendants in the open air, irritating his legs by flagellation with a wet towel, applying electro-magnetic shocks to thespine, and administering strong coffee. Bleeding has been recommended; but it is only to be used after the poison has been removed from the stomach, and when from the coma and full pulse we are sure that there is cerebral congestion. In extreme cases artificial respiration must be tried.
The remedies recommended must be perseveringly used, remembering that as long as life lasts hope of recovery is not to be banished. In the great majority of cases the treatment is successful.
Tests.—There are no direct means by which opium may be detected. We endeavor therefore to obtain evidence of the presence of morphia and meconic acid. The two substances may be separated from organic admixture by the following process: The suspected matters should be well boiled with distilled water, and spirit acidulated with acetic acid, and strained. To the fluid which has passed through, acetate of lead is to be added until precipitation ceases, and the whole, after standing, is to be thrown on a filter. The insoluble meconate of lead remains on the filter, the morphia passing through as acetate. To separate the meconic acid the substance on the filter is to be diffused through water, and sulphuretted hydrogen passed for a time. Sulphide of lead is thus thrown down and may be separated by filtration, the meconic acid remaining in solution. On concentration this should give the requisite reactions.
In the search for morphia the filtered fluid above referred to is also to be treated with sulphuretted hydrogen, to secure the precipitation of all acetate of lead, &c., which is next to be carefully separated from it by further filtration. The fluid now passing through, containing the acetate of morphia, is next to be concentrated by evaporationover a water bath, and carefully neutralized by bicarbonate of potass, if it be desired to obtain the pure alkaloid; but this is not necessary, as the acetate responds to all reagents. The acetate may be dissolved out of the mass in dilute alcohol (it is not soluble in ether), again filtered, the filtrate being finally evaporated to dryness and tested.
Morphia.—The best tests for this alkaloid, in substance or in solution (substance is preferable) are:
1. Nitric acid, which strikes an orange red color, varying in intensity with the strength of the acid and the concentration of the morphia solution. Ruddy fumes are also developed.
2. Neutral perchloride of iron, strikes a rich blue color with morphia when added in small quantity; if added in excess, the yellow of the test, combining with the blue, may produce a green. This blue is destroyed by acids and by heat. Nitric acid not only destroys the blue produced by this test, but replaces it with the orange-red color; so that the nitric acid test may be applied to the same portion of morphia after the iron test, but notvice versâ.
3. Iodic acid. This acid becomes decomposed, owing to the reducing action of morphia, setting free the iodine. The latter is detected by its brown color, and the blue which it strikes with starch. The iodic acid should be previously tested to ascertain its purity, as it occasionally contains free iodine.
4. Bichromate of potassium gives a green with morphia, passing to a dingy brown.
Meconic Acid.—This is obtained from solutions of opium, in the form of little scaly crystals of a reddish tint, which are decomposed by heat andpartly sublimed. In solution it may be detected by its acquiring a blood-red color on the addition of the perchloride of iron. A similar color is produced by sulphocyanide of potassium, as found in the saliva; but the color of the meconate is not discharged by chloride of gold; the sulphocyanide is.
Narcotinedissolves in sulphuric acid with a yellow color, converted into a carmine red by the addition of a trace of nitric acid.
The anæsthetics which have hitherto been employed in the practice of medicine are chloroform, sulphuric ether (or a mixture of these), bichloride of methylene and nitrous oxide, and amylene. Any of these agents may cause death when introduced into the system by inhalation.
Chloroformis a colorless, heavy, volatile liquid; having a fruity ethereal odor and a sweet pungent taste. It is formed by the union of chlorine and marsh gas, but more commonly by the action of bleaching powder on ethylic or methylic alcohol. It is readily soluble in alcohol, but very sparingly so in water. Chloroform is agood solvent of caoutchouc, gutta-percha, camphor, wax, resin, some of the alkaloids, &c.
Thesymptomsproduced by the vapor of chloroform may be divided into three groups of varying intensity; briefly they are these: First, a degree of relief from pain, the senses being but slightly affected; second, a stage of excitement and incoherence, wherein the patient is prone to struggle; and thirdly, a stage of which the most marked features are complete insensibility and narcotism, with relaxation of the muscular system. At first the patient is conscious of all that is passing around him, but there is dizziness and singing in the ears. Then the mental functions are impaired, there is often excitement, the saliva is increased, the patient pushes away the inhaler, rigidity and spasms of the muscles may occur, and there is incoherent talk. In the next stage there is insensibility to pain, and the conjunctiva may be touched without causing flinching. If the use of this anæsthetic be pushed further the breathing becomes stertorous, the muscles quite relaxed, and the pupils dilated; while a still further increase of the chloroform embarrasses and then stops the breathing and arrests the heart’s action.
Many cases of death from the vapor of chloroform have occurred, the fatal effect sometimes happening very rapidly from shock, syncope, or convulsions. The vapor of only thirty drops has destroyed life in one minute. Death under the influence of chloroform must not be confounded with death from its effects. The smallest fatal dose when the drug has been swallowed is one drachm in a boy aged four.
The effects of chloroform taken by the mouth are of the same description as those which follow the inhalation of this agent; with this exception,that the fatal result seems to be longer deferred. A case reported in theMedical Times and Gazette, 10th May, 1862, illustrates the symptoms, &c., in a clear way. Mr. M., thirty-four years of age, a highly-gifted restless man, was in the habit of inhaling chloroform on account of sleeplessness. He was very sensitive to its action. At about 12.30A.M.on the 7th October, 1861, he drank some chloroform; the quantity being uncertain, though it may be inferred that it was about one ounce. At 7.15 he was in such a profound sleep that his wife felt uneasy, and she sent for Dr. Axel Lamm. This gentleman found his patient in a tranquil sleep, the respiration being somewhat hurried and audible, the pulse full but slow, the body warm, and the pupils dilated and insensible. There was a perceptible smell of chloroform in the breath and in the air of the room. The window was opened, ice was applied to the head, cold affusions were used along the spine, and an enema was administered. At 9.30A.M., the patient was paler, breathing less audibly, and with a weaker pulse. Artificial respiration was employed by means of electricity, an ammonia lavement was given, and aspersions of iced water to the chest and pit of the stomach were used alternately with warm coverings. The stupor continued, the respired air smelt distinctly of chloroform, the abdomen was tympanitic, and the pupils began to contract. About 9P.M.the eyes began to move, the pupils seemed sensible to light, the pulse was 160, there was abundant perspiration, and the patient sat up for a few moments and looked surprised. Exhaustion, however, set in, and death occurred just before midnight, nearly twenty-four hours after swallowing the poison.
A second interesting case (Medical Times and Gazette, 31st May, 1862) also deserves attention.A gentleman, fifty years of age, swallowed two ounces of pure chloroform at 8A.M.He was not seen until 3P.M., when he was found in a state of deep coma. His breath smelt strongly of chloroform, the pupils were widely dilated and insensible, the pulse slow and feeble, the surface colder than natural, the movements of the thorax scarcely perceptible, and sensation generally abolished. Ammonia, sinapisms, bottles of hot water, and cold affusion did no good; but on using a stomach-pump a quantity of chloroform mixed with watery mucus was withdrawn, and in less than an hour the patient was able to answer questions. For three or four days he complained of a burning sensation in the throat and epigastrium, and then got well. A consideration of the treatment employed in this instance cannot but suggest the idea that the first patient might have had a better chance of recovery had the stomach-pump been used when Dr. Lamm was first called in; though it is difficult to conceive how any quantity of chloroform could remain in the stomach for seven hours, without all of it being absorbed.
Various plans have been suggested for the administration of chloroform with safety, but this must be remembered: the use of anæsthetics is at all times attended with risk, and we can only at best diminish the danger. Apparatus may be used so as to reduce the risk to a minimum; but this is plain, any contrivance which in itself requires much attention, and thereby diverts it from the patient, is bad. More lives have been lost by bungling in its administration than from the noxious character of the drug.
In thetreatmentof poisoning by the vapor of any of the anæsthetics mentioned in this chapter, we must expose the patient to a current of pureair, use cold affusion, and employ artificial respiration until the poison is eliminated. Galvanism may be employed to keep up the action of the diaphragm, either directly or through the phrenics. As these agents are got rid of through the lungs, the purity of the expired air is one test of the elimination being complete; though of course inferior to the evidence afforded by the subsidence of the symptoms. In poisoning by liquid chloroform or ether the stomach-pump ought to be promptly used.
Chloral Hydrate, which with an alkali is converted into chloroform, has of late been much used as a narcotic and for easing pain. No details of any case of poisoning by its agency have yet been published.
Bichloride of Methylenehas been used for anæsthetic purposes. It is supposed to be safer than chloroform. Practically they act much alike, and death happens with the one as with the other.
Test.—Chloroform at a red heat is decomposed, and chlorine and hydrochloric acid are formed. Hence, to detect it the substance supposed to contain it may be heated so as to expel the chloroform, which should be conducted away from it by a tube at right angles; to this heat should be applied sufficient to decompose the vapor, and its products searched for by the ordinary tests. The smell is a valuable criterion.
Sulphuric Ether.—Sulphuric ether, or ether, is a clear colorless liquid, very inflammable, soluble in alcohol, and less so in water. It is usually obtained by distilling common alcohol with sulphuric acid.
The effects produced by the inhalation of ether are similar to those which result from chloroform. It is, however, without doubt a much safer agent,but its effects are longer in manifesting themselves; it is more irritating to the air-passages, and much more of it is required. Deaths have occurred under its influence as under that of chloroform.
Amylene.—This is a colorless, volatile liquid, made by distilling amylic alcohol (obtained from crude fusel oil, or oil of potato spirit) with chloride of zinc.
Dr. Snow found that amylene, like chloroform, is capable of causing sudden death by inducing over-narcotism of the heart, and paralysis of this organ. He had two deaths from it, and it has since been entirely given up as an anæsthetic.
Nitrous Oxide.—Comparatively recently the laughing gas of Sir Humphrey Davy has been introduced as an anæsthetic agent. Its successful use depends on the total exclusion of air from the lungs during its exhibition. It can only be used for a short time, hence it is chiefly employed in dental operations, although it has been given for a considerable length of time consecutively by allowing the patient to return to the verge of sensibility before giving a fresh dose.
Alcohol.—Spiritous liquors, when taken in large quantities, not unfrequently produce fatal effects.
Two wineglassfuls of brandy proved fatal to a boy, seven years old, in thirty hours. Dr. Taylor mentions the case of a man who drank two bottles of port wine (containing eleven ounces of alcohol) in less than two hours. He speedily became intoxicated and utterly helpless, never rallied, and died from congestion of the brain and lungs. Another man who swallowed a bottle of gin for a wager died in half an hour, although much of the spirit was removed by the stomach-pump. A common cause of acute alcohol poisoning is “sucking the monkey,” as practised in the docks by laborers having access to spirit casks.
Thesymptomsgenerally come on rapidly, the individual appearing confused, and unable to walk steadily. This degree of intoxication soon passes into the stage of complete stupor and coma, and unless there is vomiting collapse soon sets in. In some cases a remission of the symptoms has occurred, death being postponed for a day or longer.
As the alcohol is eliminated by the lungs, stupor from drink may be detected by the odor of thebreath. The countenance is usually flushed, and the pupils are dilated, but in cases of acute poisoning the patient may be deadly pale. The pupils are not contracted, as in poisoning by opium; moreover, the individual may generally be roused for a few moments by a loud noise, &c.; a circumstance which may prevent intoxication being mistaken for concussion of the brain.
Diluted spirits produce a state of excitement, terminating in stupor. It must be remembered that alcoholic liquids have been frequently made the vehicles of more virulent poisons.
As regardstreatment, it is only necessary to say that the poison is to be removed as quickly as possible by the stomach-pump. Cold affusion should be employed, and the diluted liquor ammoniæ, or carbonate of ammonia, administered. Subsequently warmth must be promoted.
Nitro-Benzole and Aniline.—A compound, made from the rectified products of coal tar and nitric acid, and known asnitro-benzole, is sometimes used as a substitute for essential oil of almonds. It is sold to perfumers under the name of “essence of mirbane.” A lad employed in some chemical works in the early part of 1862, finding a syphon did not act, sucked through it some of the fluid, which happened to be nitro-benzole. No immediate effect resulted, but in a few hours he felt as if he were drunk. Stupor came on, and ended in death twelve hours after swallowing the poison. Another product of the destructive distillation of coal in gas-making isaniline(into which nitro-benzole is converted in the human body) a colorless, limpid, acrid, and poisonous liquid. It has given rise to very alarming symptoms when swallowed, as well as when inhaled in vapor. It produces a remarkable blue or purplediscoloration of the body, particularly the lips and nails.
Cocculus Indicus.—The kernel of the berry of the Menispermum cocculus, or Levant nut, imported from the East Indies, contains from one to two per cent. of a poisonous principle namedpicrotoxine. Thieves sometimes mix a decoction or extract of the berries with spirits or beer, to give these drinks an intoxicating property (hocussing). Dishonest publicans, too, first reduce their beer by means of salt and water, and afterwards give it intoxicating properties by adding cocculus extract. The same substance is used by poachers to destroy fish. The symptoms produced appear to be a peculiar stupor, a complete loss of voluntary power, with a consciousness of passing events.
Darnel Seeds(Lolium temulentum).—The seeds of this plant, which is often found growing with corn crops, when accidentally mixed in considerable quantity with wheat or rye, and ground into flour, have caused gastric pain, severe giddiness, vomiting, and other symtoms of intoxication. The sufferers complained that everything seemed of a green color. A wet season is said to encourage the growth of darnel with the varieties of corn.
Camphor.—This substance is very variable in its action. It has given rise to alarming symptoms on some occasions, and once it has destroyed life. In scruple and half-drachm doses, it seems to have produced giddiness, difficulty in walking, dimness of sight, difficulty of breathing, delirium, and insensibility.
The stomach-pump or emetics must be employed. If the effects are not very severe they will generally cease spontaneously after a time.The odor would lead to the detection of the poison.
Fungi.—According to Berkeley there are now upwards of 2380 recognised species of British fungi, a considerable proportion of which are doubtless poisonous. But the type of the class may be taken as the Amanita muscaria. This is an autumn fungus of an orange-red color, and is used among the Siberian tribes, especially the Koraks, as an intoxicating agent, and produces symptoms somewhat similar to those of alcohol.
The Agaricus campestris and esculentus are those most frequently used as articles of food, on account of their savory properties; but even these are indigestible. They occasionally produce diarrhœa, with a pruriginous or exanthematous rash in dyspeptics; and should only be eaten in great moderation.
Ketchup, the juice of the mushroom flavored with salt and spices, has produced faintness, nausea and colic, lasting for some hours.
There are some positive characters by which the wholesome fungi can be distinguished from the unwholesome. Moreover those which may be eaten with impunity by some individuals prove destructive to others. Thus, a French officer and his wife died from breakfasting off mushrooms which others in the house ate without inconvenience. As a general rule highly colored mushrooms, with an astringent styptic taste, a forbidding pungent odor, and which grow in dark and shady places, should be avoided.
The symptoms produced by poisonous fungi are not unfrequently those indicative of gastro-intestinal irritation, with a disordered condition of the nervous system, and considerable depression; but, again, they may act much more like pure narcotics. In treating these case, the stomach and intestines must be thoroughly emptied, and then the prominent symptoms are to be relieved according to their urgency.
Most of these are not very important substances, as they have rarely been employed as poisons in this country. Serious symptoms have, however, resulted from their accidental use.
Henbane(Hyoscyamus niger).—All parts of this plant are poisonous; but the seeds are more powerful than the root or leaves. In medicinal doses it is a feeble narcotic. It owes its powers to an alkaloid (hyoscyamia) it contains.
In very large doses henbane produces giddiness, flushings, excitement, and a sense of weight in the head; the limbs tremble, and there is general loss of power, the pupils get dilated, there is double vision, flashing of light before the eyes, and great drowsiness. If vomiting supervene these symptoms generally pass off; otherwise we may find fierce delirium, loss of speech, complete loss of power over the limbs, cold sweats, and exhaustion.
In some instances, when the roots have been eaten by mistake for parsnips, the symptoms have been those of drunkenness and delirium. Dr. Houlton states (Lancet, 6th July, 1844) that this error was committed one night at a monastery. The monks who partook of the roots had such hallucinations that the establishment resembled a lunatic asylum. They rang the bell for matins at midnight, and those who attended were unable to read, or they read that which was not in the book. In another reported case (Edin. Med. and Surg. Journal, p. 562, October, 1844), the roots were put into soup, of which nine persons partook. Although no unpleasant flavor was noticed at the time of eating, yet very shortly afterwards all complained of an acrid taste, nausea, indistinctness of vision, restlessness, delirium, and great somnolency, which continued some time.
The appearances found after death consist chiefly of great congestion of the venous system. The lungs and brain have especially been found loaded with dark-colored blood.
To prevent a fatal result from the use of henbane or others of this group, we must trust to stimulant emetics, as sulphate of zinc, and full doses of castor oil, so as to get rid of the offending substance.
Test.—The only test for hyoscyamus is the botanical characters of the plant, when taken in substance, and its power (common to all in this group) of dilating the pupil.
Atropa Belladonna(Deadly Nightshade).—Two other plants known under the name of Nightshade will hereafter be referred to. The Deadly Nightshade, now to be noticed, is indigenous, and grows in woods and gardens. The root, leaves, and berries are poisonous, this property beingdue to the presence of an alkaloidal principle—Atropia.
Symptoms.—Dryness of the mouth and throat, thirst which nothing allays, nausea and vomiting, great dilatation of the pupils with indistinct or double vision, giddiness, palpitation of the heart, physical and mental depression, perversion of the sense of taste, and delirium followed by stupor, form the chief symptoms. They may set in within from half an hour to three or four hours of swallowing the poison. Sometimes strangury and bloody urine, a scarlatinal kind of rash upon the skin, a disposition to laugh and talk wildly, fanciful delusions, a rapid flow of ideas, and difficulty in walking, have been observed.
A large detachment of French soldiers, halting near Dresden, ate freely of the belladonna berries. Shortly afterwards they were seized with nausea, thirst, dryness of the throat, difficult deglutition, insensibility of the eye, great dilatation of the pupil, delirium, and coma. Many of the men died before assistance could be rendered to them.
Post-mortem Appearances.—Congestion of the cerebral vessels, dilated pupils, red patches at different parts of the alimentary canal, and a dyed purple hue of the gastric mucous membrane, if the berries have been eaten, are the most common appearances.
Treatment.—Stimulant emetics, castor oil, and animal charcoal are the remedies to trust to.
Dr. Taylor refers to one case in which a young man poisoned himself with two grains ofatropia. He took the dose on going to bed, was heard to snore heavily during the night, and was found dead at seven o’clock in the morning.
As a means of diagnosing poisoning by belladonna it has been recommended to introduce afew drops of urine into the eye of an animal, to see if dilatation of the pupil takes place.
Test.—There is no very certain test forAtropiabeyond its effect on the pupils and on vision.
Stramonium(Datura Stramonium,Thorn-Apple) is an indigenous plant found in waste places. The fruit and seeds are the most poisonous parts of the plant. The active alkaloid, named Daturia, has properties resembling those of atropia, with which it would seem to be almost identical.
The poisonous effects of stramonium are the same as those of belladonna, and are to be relieved by similar remedies. When this drug is prescribed as a medicine it should be immediately discontinued if it produce dryness of the throat and dilatation of the pupils.
Dhatoora.—In India the seeds of the Datura alba, a plant which grows abundantly in most parts, are frequently used for the purpose of hocussing travellers, in order that they may be robbed with impunity. The seeds, which closely resemble those of the capsicum, are mixed with food, and give rise to total insensibility on the part of the recipient, often with noisy delirium or delusions. Death is not unfrequent after a large dose, although it would seldom seem to be administered for that purpose. Its effect may be for the time being to completely alter the disposition of the individual, and to cause him to give way to all kinds of foolish notions and antics.
Nightshade.—TheSolarium dulcamara(Bittersweet, or Woody Nightshade) and theSolanum nigrum(Garden Nightshade) contain an active principle known as Solania. The red berries of the first-named plant, and the black berries of the second, have been eaten by mistake; and have given rise to great thirst, headache, giddiness,dimness of vision, dilated pupils, convulsions, vomiting, and purging. Orfila relates the cases of three children who died from eating the berries of the Solanum nigrum, after suffering from vertigo, dilated pupils, nausea, colic, stertorous breathing, and convulsions.
The plants which yield the alkaloid Strychnia are, theStrychnos nux vomica, a native tree of Coromandel, Ceylon and Bengal: theStrychnos Ignatii, which abounds in the Philippine Islands, and furnishes the hard seed, about the size of a filbert, known as the bean of St. Ignatius; theStrychnos tieute, a large climbing shrub of Java; theStrychnos toxifera, of Guiana; and theStrychnos colubrina, orSnakewood, of the East Indies. The effects of these plants are exerted upon the spinal cord; as is manifest by the violent convulsions and the tetanic contractions of the muscles which they produce. They have no effect on the brain, consciousness remaining intact until death.
A powerful juice, used by the Indians of Guiana as an arrow poison, and variously designated ascurare,woorara, &c., is in all probability obtained from the Strychnos toxifera. The composition of the arrow poison varies in different tribes; in some it is a mysterious compound of many substances,obtained from plants, red and black ants, and the fangs of venomous snakes; but in all the active ingredient would seem to be the Strychnos toxifera. It destroys the power of the motor nerves—an action the reverse of that possessed by strychnia.
Nux Vomica.—A powder, a tincture, and an extract, obtained from the seeds of the Strychnos nux vomica, or koochla tree, are used in medical practice. Thirty grains of the powder have proved fatal, and so have three grains of the alcoholic extract. Death may occur in from fifteen minutes to twelve hours. It is possible that nux vomica may accumulate in the system, as serious symptoms have arisen from the long-continued use of small doses. Thus a lady took nine grains of the powder daily, in divided doses, for sixteen days. As purging then set in with colic, the medicine was withdrawn. Five days after the withdrawal there was ringing in the ears, with drowsiness, impairment of speech, &c.; on the ninth day tetanic symptoms set in, with trismus; and on the twelfth day, after several tetanic convulsions, death took place from exhaustion.
Brucia.—The seeds of the nux vomica not only yield strychnia but brucia, an alkaloid which has the same properties, and causes the same symptoms as strychnia, though it is much less powerful.
Strychnia.—This alkaloid may very justly be termed a deadly poison. It is unfortunately the active ingredient of some preparations sold to the public for destroying vermin: a circumstance which has now led to the death of several individuals. “Battle’s Vermin Killer” is said by Dr. Letheby to consist of flour, Prussian blue, sugar, and strychnia in the proportion of twenty-three per cent. Since the use of strychnia by those notorious criminals Palmer and Dove, this formidable agent has been employed by other murderers.
The medicinal dose of strychnia is from the1⁄30th to the1⁄12th of a grain twice a day. Dr. Christison communicated a case to Dr. Taylor in which the1⁄16th of a grain caused the death in four hours of a child between two and three years of age. One quarter of a grain has nearly proved fatal to adults. A woman twenty-two years of age died in the Jersey Hospital, from the accidental administration of half a grain. Death has occurred in twenty minutes from this poison. In eleven cases analyzed by Dr. Guy two hours and three-quarters were the limits respectively.
Symptoms.—The time at which the symptoms commence varies according as the strychnia has been taken in solution or in a pill. In the first case a very bitter taste is experienced during swallowing, usually followed in a few minutes by a sense of suffocation and difficulty of breathing. Then there are twitchings of the muscles, jerking movements of the limbs, and a quivering of the whole frame. The limbs become rigid, the head is bent back, while the body is stiffened and arched, so that it rests on the head and heels (opisthotonos). The difficulty of breathing causes the face to become dusky, the eyeballs prominent, and the lips livid. The features assume a peculiar grin (risus sardonicus); there is much thirst, but perhaps inability to drink from spasm of the jaws; while the sufferer is quite conscious, is much alarmed, and is impressed with the idea that death is surely stealing upon him. As the attacks of spasms are commencing the patient cries out, and warns those about him of the approach of the seizure; he begs for help, and perhaps asks to be held, or rubbed, or turned over; and when theseizure passes off, at the end of forty or sixty seconds, he is exhausted, and bathed in sweat. The more he is disturbed or excited the shorter is the intervals between the attacks; and though a firm grasp seems to afford relief, yet a slight touch, a gust of air, or opening a door, will increase the suffering. As death approaches the tetanic spasms rapidly succeed each other; and the patient sinks, suffocated during an attack, or exhausted during an interval, in about two hours from the beginning of the symptoms.
When the strychnia has been taken in a pill two hours have elapsed before any effects have been produced. A case is also reported (Glasgow Medical Journal, July, 1856) where a medical man took three grains of strychnia dissolved in spirits of wine and diluted sulphuric acid. He went to bed and slept for an hour and a half, and then awoke with a spasm. Under treatment he recovered.
There is commonly a wide difference between tetanus arising from a wound or from disease and that provoked by strychnia. In the former case some exciting cause can be detected; the symptoms come on gradually, and only attain their full development at the end of several hours; the rigidity of the muscles is more or less permanent, there being no intervals of relaxation as there are in poisoning; and death has hardly been known to occur in less than twenty-four hours, while frequently it is deferred for two or three days.
Post-mortem Appearances.—Although the body may be relaxed at the time of death it usually quickly stiffens—frequently in the course of ten or fifteen minutes. The rigor mortis is persistent for some time: in the case of Cook, poisoned by Palmer, the rigidity of the body and limbs was said not to have passed off after two months’ interment.This is not however invariable, as a body may be flaccid or stiff after death from this cause as from any other. The hands are often clenched, and the soles of the feet arched and inverted. The membranes of the brain and of the upper part of the spinal cord are congested; and there is often considerable serous effusions under the spinal arachnoid. The lungs are generally loaded with dark fluid blood. The heart is usually contracted, but sometimes the right cavities are distended like the pulmonary vessels. The blood has been found black and liquid.
Treatment.—Emetics are to be given at once, and repeated until very free vomiting is induced. If the tetanic spasms have not commenced, the stomach-pump ought to be used. Chloroform is to be given to relieve spasm and pain, but the patient should be disturbed as little as possible, as the least thing induces the tetanic attack. There is no very suitable antidote, but tannic acid, in the form of green or black tea, &c., might be given.
Iodine forms a crystallizable compound with strychnia. Dr. Bennett, of Sydney, has recorded an instance in which he attributed recovery to the employment of tincture of iodine. Hence from thirty minims to a drachm of this tincture combined with the iodide of potassium may be exhibited. In its absence, three or four ounces of animal charcoal, diffused through water, ought to be given.
To prevent the spasms by paralyzing the motor nerves, a solution of curare has been recommended by Dr. George Harley to be injected under the skin; or, if it could be obtained, the active principle of this substance, curarina, would perhaps be deserving of trial.
The patient is to be kept warm and quiet.
To separate strychnia from organic admixture the process modified from Stas, given in the beginning of this book, is the most useful.
Tests.—Strychnia is a white crystalline solid, very insoluble in water, soluble in alcohol or chloroform or weak acids, and having an intensely bitter taste.
1. Pure strychnia is not changed in color when treated with iodic acid or with either of the strong mineral acids; but as this alkaloid generally contains brucia, nitric acid reddens it.
2. Dissolved in sulphuric acid no change ensues; but on adding a fragment of bichromate of potass to the solution a series of blue, violet, purple and red tints are produced. The same result is brought about by using ferricyanide of potassium, permanganate of potassium, the peroxide of lead, or the black oxide of manganese.
3. If the skin of a frog be dried, and a few drops of a solution containing strychnia applied to it, strong tetanic convulsions will ensue, and be reproduced every time the animal is touched or irritated. According to Dr. Marshall Hall this strychnoscopic test will detect the1⁄5000th of a grain, or even less.
4. An exceedingly useful class of tests for many poisons has been introduced by Dr. Guy; we mean the crystalline appearances presented on subliming the substance and condensing it on a cool microscopic slide, or the crystalline form observed as modified by various reagents. Thus the strychnine sublimate, touched with a drop of carbazotic acid, forms groups of arborescent crystals, each branch forming part of a circle, when seen under the microscope.