7. _Arseniuretted-Hydrogen._

This compound presents the form of a colourless gas, possessing a fetid garlicky odour, a density of nearly 2·7, and great virulence as a poison. It is mentioned here, because accidental poisoning with it has happened occasionally within a few years, chiefly owing to the occasional adulteration of sulphuric acid with arsenic, and the liability of the arsenic to form arseniuretted-hydrogen when such sulphuric acid is used to prepare hydrogen gas. Dr. O’Reilly has mentioned a melancholy instance of a young chemist losing his life in this way.[565] Dr. Schlinder of Greifenberg has related another, which did not prove fatal.[566] And it is well known that the German chemist Gehlen lost his life by accidentally breathing arseniuretted-hydrogen while engaged in examining its chemical properties.[567] It is an inflammable body; and its presence in any other gas is easily detected by burning it according to the method of Marsh. SECTION II.—_Of the Action of Arsenic and the Symptoms it excites in Man._ It is now generally admitted that arsenic produces in the living body two classes of phenomena,—or that, like the narcotico-acrids, it has a twofold action. One action is purely irritant, by virtue of which it induces inflammation in the alimentary canal and elsewhere. The other, although it seldom occasions symptoms of narcotism properly so called, yet obviously consists in a disorder of parts or organs remote from the seat of its application. It is also the general opinion of toxicologists, that arsenic occasions death more frequently through means of its remote effects than in consequence of the local inflammation it excites. In some cases indeed no symptoms of inflammation occur at all; and in many, although inflammation is obviously produced, death takes place long before it has had time to cause material organic injury. Nevertheless in some, though certainly in comparatively few instances, the local action, it must be admitted, predominates so much, that the morbid changes of the part primarily acted on are alone adequate to account for death. Its chief operation being on organs remote from the part to which it is applied, a natural object of inquiry is, whether this action results from the poison entering the blood, and so passing to the remote organs acted on, or simply arises from the organ remotely affected sympathizing through the medium of the nerves with the impression made on the organ which is affected primarily. On this question precise experiments are still wanted. The general opinion has for some time been that it acts through the blood. And this view has of late been strengthened by indisputable evidence, that the poison does enter the blood, and is diffused by it throughout the body. For a long period chemists sought in vain for arsenic in the animal tissues and secretions at a distance from the alimentary canal. Such was the position of matters at the date of the last edition of this work; in which the failure was ascribed to the methods of analysis then known not being delicate enough to discover the small quantity of arsenic which disappears by absorption in cases of poisoning.[568] That statement is now referred to, because in a late controversy in France an attempt was made, by an erroneous quotation of this work, to deprive Professor Orfila of the honour, which is due to him alone, of having recently been the first to demonstrate the possibility of detecting arsenic throughout the organs and secretions generally of the bodies of men and animals poisoned with it. This most important discovery, pregnant alike with interesting physiological deductions and valuable medico-legal applications, was first announced by him to the Parisian Academy of Medicine in January, 1839; when he stated that arsenic is absorbed in such quantity in cases of poisoning as to admit of being discovered by an improved process of analysis in various organs and fluids of the body, such as the liver, spleen, kidneys, muscles, blood, and urine.[569] In November, 1840, he proved these facts to the satisfaction of a committee of the academy.[570] And since then they have been confirmed by others, not merely in express experiments, but likewise in the familiar experience of medico-legal practice. The situations where arsenic is met with in largest quantity are the liver, the spleen, and the urine, but above all the liver. The precise circumstances in which it may be found in one or another of these quarters have not yet been determined. But in most cases of acute arsenical poisoning where the search has been made at all, it has proved successful in the liver. In two late instances I have readily found arsenic by the process of Marsh or Reinsch in the liver after four months’ interment. Since arsenic then is clearly absorbed into the blood, it becomes an interesting question whether the organization of the blood is thereby changed. This question cannot be answered with confidence. But in all probability the blood does undergo some change in its _crasis_; for in most cases of acute poisoning that fluid is found after death in a remarkable state of fluidity [see Section on the Morbid Appearances]; and Mr. James observed that if venous or arterial blood be received into a solution of arsenic, instead of coagulating in the usual way, a viscous jelly first forms, and lumpy clots separate afterwards.[571] Our knowledge of the affection induced by the remote action of arsenic is in some respects vague. Toxicologists have for the most part been satisfied with calling it a disorder of the general nervous system. When employed to designate the state of collapse which accompanies or forms the chief feature of acute cases of poisoning with arsenic, this term is misapplied. The whole train of symptoms is that not of a general nervous disorder, but simply of depressed action of the heart. That this is the chief organ remotely acted on in such cases farther appears probable from certain physiological experiments, in which it has been remarked, that immediately after rapid death from arsenic the irritability of the heart was exhausted or nearly so, while that of the intestines, gullet, and voluntary muscles continued as usual.[572] As to the singular symptoms which often arise in the advanced stage of lingering cases, the term, disorder of the general nervous system, is more appropriately applied to them. They clearly indicate a deranged state sometimes of the brain, sometimes of particular nerves. Arsenic belongs to those poisons which act with nearly the same energy whatever be the organ or texture to which they are applied. The experiments of Sproegel,[573] repeated by Jaeger,[574] and by Sir Benjamin Brodie,[575] leave no doubt, that when applied to a fresh wound it acts with at least equal rapidity as when swallowed. Although in such circumstances the signs of irritation are often distinct, yet the symptoms are on the other hand sometimes more purely narcotic than by any other mode of administering it,—Sir B. Brodie in particular having observed loss of sense and motion to be induced, along with occasional convulsions. Arsenic likewise acts with energy when applied to the conjunctiva of the eye, as was proved by Dr. Campbell. It acts too with great energy when inhaled in the state of vapour into the lungs, or in the form of arseniuretted-hydrogen. It farther acts with violence through the mucous membrane of the vagina, producing local inflammation, and the usual constitutional collapse. These facts were determined experimentally by the Medical Inspectors of Copenhagen on the occasion of a singular trial which will be noticed afterwards. Arsenic also acts, as may easily be conceived, when injected into the rectum. And farther, it acts as a poison, when it is applied to the surface of ulcers, yet certainly not under all circumstances. Its power of acting through the unbroken skin has been questioned. Jaeger found that, when it was merely applied and not rubbed on the skin of animals, it had no effect.[576] But some cases will be afterwards mentioned which tend to show that the reverse probably holds in regard to man. According to the last-mentioned author, who is the only experimentalist that has hitherto examined the subject consecutively, arsenic is most active when injected into a vein, or applied to a fresh wound, or introduced into the sac of the peritonæum; it is less powerful when taken into the stomach; it is still less energetic when introduced into the rectum; and it is quite inert when applied to the nerves. It is a striking fact in the action of that poison that, whatever be the texture in the body to which it is applied, provided death do not ensue quickly, it almost always produces symptoms of inflammation in the stomach; and on inspection after death traces of inflammation are found in that organ. In some instances of death caused by its outward application, the inflamed appearance of the stomach has been greater than in many cases where it had been swallowed. Sproegel met with a good example of this in a dog killed by a drachm applied to wounds. The whole stomach and intestines, outwardly and inwardly, were of a deep-red colour, blood was extravasated between the membranes, and clots were even found in the stomach.[577] Of the different preparations of arsenic, it may be said in general terms, that those are most active which are most soluble. In conformity with what appears to be a general law in toxicology, the metal itself is inert. It is difficult to put this fairly to the test, because it is not easy to pulverize the metal without a sufficient quantity being oxidated to cause poisonous effects. Bayen and Deyeux, however, found that a drachm carefully prepared might be given in fragments to dogs without injuring them; and they once gave a cat half an ounce without any other consequence than temporary loss of flesh.[578] Its alloys are also inert. The same experimentalists found it inactive when combined with tin; and Renault likewise found it inactive when united with sulphur and iron in the ore mispickel, or arsenical pyrites.[579] It is probable that all the other preparations of arsenic are more or less deleterious. A difference of opinion prevails as to the power of the sulphurets. Various statements have been published on the subject. But it may be sufficient to observe, that in consequence of the poisonous properties of the sulphurets having been imputed to the oxide, with which they are often adulterated,—Professor Orfila made some experiments with native orpiment and realgar, and with the sulphuret procured by sulphuretted-hydrogen gas (which are all pure sulphurets); and he found that in doses varying from 40 to 70 grains they all caused death in two, three, or six days, whether they were applied to a wound, or introduced into the stomach.[580] It may appear at first view singular that the sulphurets, being insoluble, should be poisonous; but the apparent anomaly vanishes on considering the experiments of M. Decourdemanche formerly noticed; which prove that in animal fluids the sulphurets are rapidly changed into the oxide (see p. 225). The sulphurets, however, are much less active than the preparations in which the metal exists already oxidated. Yet in sufficient doses they will prove rapidly fatal. In the Acta Germanica there is the case of a woman who was killed in a few hours by realgar, mixed by her step-daughter in red cabbage soup.[581] The common artificial orpiment procured by sublimation is very active, in consequence of the oxide mixed with it. Renault found three grains killed a dog in nine hours.[582] Among the less active preparations of arsenic may also be enumerated such of the arsenites and arseniates as are not soluble in water. They have not indeed been actually tried. But there can be little doubt that they will prove poisonous; because, though insoluble in water, they are probably somewhat soluble in the animal juices. We may infer from their sparing solubility, even in these menstrua, that they will be less active than the preparations now to be mentioned, which are more soluble. These are the alkaline arsenites and arseniates, arsenic acid, arsenious acid, the black oxide or fly-powder, and arseniuretted-hydrogen. With regard to arsenic acid, and the alkaline arseniates and arsenites, it is probable, from their effects in medicinal doses, that they are as active as the white oxide, if not more so. But they have not been particularly examined, as they are not objects of great interest to the medical jurist. The fly-powder or black oxide is very active. Renault found that four grains killed a middle-sized dog in ten hours.[583] It has been likewise known to prove quickly fatal to man. In a French journal there is a case related which ended fatally in sixteen hours;[584] and in the Acta Germanica is an account of four persons, who died in consequence of eating a dish of stewed pears poisoned with it, and of whom three died within eighteen hours.[585] The dose is not mentioned; but it is probable from the collateral circumstances that it was not considerable. Arseniuretted-hydrogen is probably the most active of all arsenical compounds. The celebrated German chemist Gehlen, having accidentally inhaled a small portion of it, died in nine days with the usual symptoms of arsenical poisoning. In Dr. O’Reilly’s case, which proved fatal in seven days, it was computed that the equivalent of twelve grains of oxide had been inhaled. And Dr. Schlinder’s patient had inhaled a quantity of gas corresponding with only an eighth of a grain of sesquioxide; yet he appears to have made a narrow escape.[586] It is of some consequence to settle with precision the power of the white oxide. Witnesses are often asked on trials how small a quantity will occasion death? It is obvious that this question admits only of a vague answer: It can be answered at all only in reference to concomitant circumstances, and even then but presumptively. Nevertheless, it is right to be aware what facts are known on the subject. It has been stated by various systematic authors that the white oxide will prove fatal to man in the dose of two grains. Hahnemann says in more special terms, that in circumstances favourable to its action four grains may cause death within twenty-four hours, and one or two grains in a few days.[587] But neither he nor any of the other authors alluded to have referred to actual cases. Foderé knew half a grain cause colic pains in the stomach and dysenteric flux, which continued obstinately for eight days;[588] and I have related an instance where six persons, after taking each a grain in wine during dinner, were seriously and violently affected for twelve hours.[589] Mr. Alfred Taylor mentions three similar cases occasioned by arsenic accidentally taken in port wine after dinner,—one, an infant of sixteen months who got about a third of a grain, another, a lady who took a grain and a half, and the third, a gentleman, who had two grains and a half,—in all of whom violent vomiting, and prostration, without pain, occurred for three or four hours; and the gentleman of the party did not recover for several days.[590] M. Lachèse mentions his having met with a number of cases of poisoning from small doses taken in bread or soup; whence he concludes, that an eighth of a grain taken in food may cause vomiting;—that a quarter of a grain or twice as much taken once only causes vomiting, colic, and prostration,—that the same quantity repeated next day renews these symptoms in such force as to render the individual unfit for work till three or four days afterwards,—and that four such doses, taken at intervals during two days, that is between one and a half and two grains in all, excite acute gastro-enteritis and may prove fatal, since two individuals who had taken this much died, one in seven weeks, the other three weeks later.[591] The smallest fatal dose I have found recorded elsewhere is four grains and a half; and death ensued in six hours only.[592] But the subject was a child, four years old, and the poison was taken in solution. Alberti mentions the case of a man who died from taking six grains; but I am unacquainted with the particulars, not having seen the original account.[593] Two children, whose cases are alluded to in the Proceedings of the Academy of Medicine of Paris, died, the one in two days, the other a day later, after taking rather less than sixteen grains. The former was four years and a half old, the latter seven years.[594] Valentini alludes to a case where thirty grains of the oxide in powder killed an adult in six days.[595] The effects of medicinal doses, which seldom exceed a quarter of a grain without causing irritation of the stomach, and the fatal effects of somewhat larger doses on animals, Renault having found that a single grain in solution killed a large dog in four hours,[596] must convince every one that the general statement of Hahnemann cannot be very wide of the truth. Mr. Taylor thinks his own cases mentioned above throw doubt over this inference. But it must be remembered, that his patients had dined just before taking the poison. It is not improbable that the activity of oxide of arsenic is impaired by admixture with other insoluble powders. M. Bertrand, conceiving from some experiments on animals that he had found an antidote for arsenic in charcoal powder, took no less than five grains of the oxide mixed with that substance, and he did not suffer any injury, although his stomach was empty at the time, and he did not vomit.[597] But Orfila afterwards showed, that other insoluble powders, such as clay, have the same effect; that no such powder can be of any use if not introduced into the stomach till after the arsenic is swallowed; and that they appear to act solely by enveloping the arsenical powder and preventing it from touching the membrane of the alimentary canal.[598] Although M. Bertrand’s discovery will not supply the physician with an antidote, the medical jurist will not lose sight of the interesting fact, that, by certain mechanical admixtures, arsenic in moderate doses may be entirely deprived of its poisonous quality. A singular case of recovery from no less a dose than sixty grains, which happened in the case of an American physician, probably comes under the same head with the experiments of Bertrand,—a large quantity of powder of cinchona-bark having been swallowed along with the arsenic. In this case, however, the symptoms were severe for three days.[599] The tendency of habit to modify the action of arsenic is questionable. So far as authentic facts go, habit has no power of familiarizing the constitution to its use. One no doubt may hear now and then of mountebanks who swallow without injury entire scruples or drachms of arsenic, and vague accounts have reached me of patients who took unusually large doses for medicinal purposes. But as to facts of the former kind, it is clear that no importance can be attached to them; for it is impossible to know how much of the feat is genuine, and how much legerdemain. With respect to the latter facts, I have never been able to ascertain any precise instance of the kind; and so far as my own experience goes, the habit of taking arsenic in medicinal doses has quite an opposite effect from familiarizing the stomach to it. Oxide of arsenic being sparingly soluble, its operation is often much influenced by the condition of the stomach as to food at the time it is swallowed. If the stomach be empty, it adheres with tenacity to the villous coat and acts with energy. If the stomach be full at the time, the first portions that come in contact with the inner membrane may cause vomiting before it can be diffused, so that the whole or greater part is discharged. One remarkable case of this nature has been quoted in page 29. In another, where severe symptoms did supervene, and recovery was ascribed to the use of magnesia as an antidote, the favourable result seems to have been really owing to the circumstance, that the patient had supped heartily not long before taking the arsenic.[600] An extraordinary case related by Mr. Kerr, in which nearly three-quarters of an ounce were retained for two hours without causing any serious mischief, probably comes under the same category; for the arsenic was taken immediately after a meal, and the stomach was cleared out by emetics.[601] In the following detail of the symptoms caused by arsenic in man, its effects when swallowed will be first noticed; and then some remarks will be added on the phenomena observed when it is introduced through other channels. The symptoms of poisoning with arsenic may be advantageously considered under three heads. In one set of cases there are signs of violent irritation of the alimentary canal and sometimes of the other mucous membranes also, accompanied with excessive general depression, but not with distinct disorder of the nervous system. When such cases prove fatal, which they generally do, they terminate for the most part in from twenty-four hours to three days. In a second and very singular set of cases there is little sign of irritation in any part of the alimentary canal; perhaps trivial vomiting or slight pain in the stomach, but sometimes neither; the patient is chiefly or solely affected with excessive prostration of strength and frequent fainting; and death is seldom delayed beyond the fifth or sixth hour. In a third set of cases life is commonly prolonged at least six days, sometimes much longer, or recovery may even take place after a tedious illness; and the signs of inflammation in the alimentary canal are succeeded or become accompanied, about the second or fourth day or later, by symptoms of irritation in the other mucous passages, and more particularly by symptoms indicating a derangement of the nervous system, such as palsy or epilepsy. The distinctions now laid down will be found in practice to be well defined, and useful for estimating in criminal cases the weight of the evidence from symptoms.