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North Canterbury Gazette, Volume I, Issue 2, 19 August 1932, Page 12

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Science and the Criminal [By HENRY T. F. RHODES, Editor of the “ Chemical Practitioner."] • Exclusive to “North Canterbury Gazette.” World Copyright reserved by Reuters. ii. ' „ MODERN POISONERS AND '• „ ■ 'i;; 4 .. •, ' i r: • /:.; ♦. v ; ./ •• . .... ‘ ' THEIR DETECTION.

jk RSENBC has been called the fool’s /\ poison; never was anything less aptly named. There are poisoners who use their instrument so foolishly as to make it possible to classify the crime with those of violence. Unfortunately this is not common. Poisoning is not only the most revolting, but it is the most dangerous type of crime, because the most difficult to detect. The poisoner is generally to be found among the more cultivated members of the community. He must be subtle and a clever hypocrite. Case upon case bears this contention out. Arsenic is not the fool’s poison, nor is it time that its popularity is due to the unimaginativeness of the criminal. The poisoner is* seldom stupid or unimaginative. On the contrary, the evidence is all the other way. As a poison, assenic retains its popularity for the reason that it is still the safest poison to use. In the first place a physician has the greatest difficulty in diagnosing arsenical poisoning unless he has .some reason to suspect it. If carefully graduated doses are administered the symptoms almost exactly resemble those of gastro-enteritis or cholera, and the victim may die from apparently natural causes. The position of the medical man, even, if he suspects poison, may be very delicate, and it is a tribute to the profession that so few cases of poisoning by arsenic appear to escape its vigilance. As a recent case has shown, however, there are exceptions —proof, if any were required, that arsenic is still a dangerous weapon in the hands of an expert. Further, arsenic can be purchased in forms which do not excite much suspicion. Small quantities cannot legally be sold without admixture with soot or indigo. This is to some extent a protection, hut those with a little knowledge can still separate the colouring matter and it is impossible to

devise means, short of prohibiting the sale of any form of arsenic altogether, that will prevent its use as a lethal agent. The advance of chemical science has nevertheless made things increasingly difficult for the poisoner. Once poisoning with arsenic is suspected, the chemist can get to work and trace the minutest quantity with deadly accuracy. Here is a picture of him at work in his laboratory. Samples of food or .medicine have'been submitted to him in which the presence of arsenic is suspected. The chemist carefully weighs out a portion of the food. It is then put into a glass flask and treated with potent acids. Heavy fumes are evolved and substances which interfere with the subsequent test are thus destroyed. The acid mixture is at first dark coloured, and then yellow; finally it clears. There will not be very much, but in that small quantity of colourless solution the arsenic, if any is present, is hidden. The next step is to make it reveal itself.

This-is done by means of an apparatus which generates hydrogen. Zinc and sulphuric acid are used to make the gas. The solution suspected to contain the arsenic is introduced into the apparatus. . The arsenic forms a gaseous compound with, hydrogen, but the apparatus is so constructed that the hydrogen escapes, but the arsenic is trapped in a tiny tube near the gas exit. It betrays itself as a. black stain or mirror, as the chemist calls it, which adheres to the side of the tube. Upon the ’size of that black stain a man’s life may depend. It can be accurately measured and compared with stains produced from experiments with known quantities of arsenic. The poison can thus not only be detected but its quantity can be exactly estimated. The test is so delicate that it can detect as little as one part in five million parts of suspected material.

This test is known as the MarshBerzelius test and it sounds simple enough. As a matter of fact there is nearly a hundred years of patient research behind the method, and it is practically as near perfection as any scientific test can be. This small piece of apparatus which measures a black stain has probably done as much to avenge the victims of the poisoner, and to deter others, as all the rest of the preventive legislation put together.

It has done more. If it convicts the guilty, it also protects the innocent. In the past it has sometimes been deemed sufficient to prove that the accused person purchased arsenic Avitbout an examination as to Avhether, in fact, any was present in the food of the alleged A r ictim or in the body. Such evidence is regarded as seriously defective. If

no arsenic is found in a body or in the remains of food, part of which has been proved to have been consumed by the.dead person, then it is beyond all doubt that no arsenic is there. The Marsh-Berzelius test never fails, and it can distinguish with absolute certainty between a fatal and a non-fatal dose. < .

There may be, of course, unusual collateral circumstances which introduce doubts as to fact. Some of them are of great interest. Two grains of arsenic have been known to cause death and three are very commonly a fatal dose, but cases have arisen where a so-called arsenic eater has been the alleged victim of poisoning by arsenic. Some people become addicted to the habit of taking arsenic which in small quantities is a valuable tonic. There .are examples of continuous use where individuals 'have taken as much as five or six times the fatal dose apparently lvithout ill effects. Such unusual circumstances may, and in the famous case of Mrs. Maybrick did, considerably complicate the evidence. It is decidedly awkward for the prosecution if, after great pains to show that considerably more than a fatal quantity of the poison was found, it is faced Avith evidence proving that the victim was in the habit of taking a large dose of arsenic as a reviver before breakfast.

Exceptions of this kind, hoAvever, have no bearing upon the accuracy of the test itself. They are exceptions and ones of very rare occurrence. The Marsh-Berzelius test for arsenic has had a romantic and chequered career. It has figured in many great trials, and it did not always command the respect that it does to-day. As we have already explained, it Avas not perfected at once. Scientists, no less than other people, learn by their mistakes. British legal procedure makes it practically impossible for a mistake, Avhether made by an expert or an ordinary witness, to pass unnoticed. In a subsequent chapter this question will be considered.

Although arsenic has always been a favourite with the poisoner, it' must not be supposed that the use of other poisons is only occasional. Murderers have employed the rarer alkaloidal poisons in the hope that the difficulty attending their detection would make conviction impossible. In the early days of toxicology it is not improbable that many poisoners escaped not only conviction but trial. Who shall say how many deaths supposed to be due to natural causes Avere not the result of poisons at that time obscure? Very often the poisoner has drawn suspicion upon himself by some foolish action Avhich a moment’s reflection would avoided. But there is only evidence of this in the case of those Avho have been convicted. Many more, avoiding such mistakes, may have escaped the penalties of the law altogether. Things are very different to-day. Physicians Avill not give a certificate Aintil they are quite satisfied as to the cause of death, and there is scarcely a poison

that oan escape the vigilance of the analyst. Even as long ago as the beginning of the nineteenth century the science of poison detection Avas beginning rapidly to improve, largely as the result of the classical Avork of the famous French chemist and toxicologist, Orflla. He was among the first to) recognise the importance of chemistry in the detection of crime, and in particular the necessity of tracing the presence of poison in the body of the victim. In 1823 Orfila, stated that lie could estimate one-fifth of a grain of acetate of morphine in one pint of liquid. But sometimes mistakes Avere made. One of these we shall presently consider. Indeed, it was not until many years afterwards that it was possible to detect the alkaloidal poisons with any certainty. In 1881 George Henry Lamson was tried for the murder of his brother-in-law by poisoning him with aconitine. Beyond the fact that Lamson benefited by his brother-in-huv’s death and that he had visited him shortly before he died, there was no collateral evidence, except the symptoms, to suggest poisoning. Twenty years before, the death might have passed as from natural causes. Physicians, however, were becoming more watchful, and diagnosis had improved. Chemical science also. A postmortem was carried out and the organs analysed. The presence' of morphine and aconitine were detected by the general chemical reactions, and the presence of the latter confirmed by physiological reactions. The crime had been planned Avith devilish ingenuity. Dr. Lamson called upon his brother-in-IaAV, who was a lad still at school, bringing with him some sweets and a cake. The doctor gave pieces to the schoolmaster and the boy, and ate some himself. He left soon afterwards for Paris. The same evening the hoy became ill, and although doctors were immediately summoned he died soon after their arrival. Lamson was suspected since it Avas later proved he had purchased aconitine on occasions; and from the post-mortem there was no doubt that an irritant poison had been administered. But the question Avas how had it been administered? Dr. Lamson and the schoolmaster had themselves shared the sAveets and cake that the doctor had brought Avith him to the school. This mystery Avas solved at the trial. One slice of the' cake Avas already cut Avhen Lamson arrived at £he school. A raisin had been removed from this slice and something more than a fatal dose jof the deadly drug had been secreted in it. The raisin Avas then replaced in the slice of cake. It Avas this fatal portion Avhich Avas gi\ T en to the unfortunate hoy. Dr. Lamson had hoped in this Avay not only to divert suspicion from himself by concealing the method by Avhich the poison had been administered, but he also expected that its introduction into the raisin Avould delay the action of the aconitine,, and thus further confuse the evidence as to the time Avhen it Avas administered.

Although these precautions availed

him nothing, the prosecution did hot 'have things all its own way. The defence claimed that it was not proved that there was aconitine /in the body. Experts for the prosecution, they said, had made experiments upon mice by injecting extract's of the supposed aconitine which had. killed them. This proved nothing since an injection of pure water would kill such delicate animals in some circumstances. The defence further roundly maintained that if the physiological tests on mice were unreliable, the chemical tests were even less conclusive.

It was too hopeless a task. The symptoms accompanying the death of the mice agreed with those of aconitine poison. The interesting fact also emerged that Dr. Stevenson, one of the experts for the prosecution, had experimented upon himself! He had placed a small drop of the extract from the organs upon his tongue, and had experienced that peculiar numbness and tingling associated with this alkaloid.

Dr. Lamson was convicted and sentenced to death. He at first proclaimed his innocence, but afterwards confessed.

The case of Lamson was one of the first solid triumphs for scientific detection of a rare poison. The triumph would have been greater had it been possible to decide the matter on chemical tests alone, since chemistry is an exact • science in a sense that physiology is not; but the case was proved up to the hilt. France is * said to have employed scientific methods of detection more consistently than any other country in Europe. However this may be, it is certainly true that the earliest case of the detection of an alkaloidal poison by micro-chemical means belongs to France.

In 1884 a medical man named Eustachy was tried for poisoning his victim with atropine. Atropine was at that time by no means an easy ‘poison to detect, but the toxicologist retained in the case invented a. method. He isolated some crystals from the body which he suspected to be those of atropine. But how was it to be proved? The toxicologist devised a. means, beautifully which has been much used since. He photographed the suspected crystals through a microscope. These were compared with a photomicrograph of crystals of pure atropine; the two were similar in appearance, and the suspicion became a certainty. This may appear to be slender evidence until it is explained that different chemical substances have characteristic crystalline forms by which they can be recognised and distinguished with certainty. Special compounds of the substances to be examined have to be prepared which give a definitely characteristic crystalline form. Once this is done they are. readily detected with the aid of the microscope. This branch of chemical work is known as micro-chemical analysis. Later on we shall see that micro-chemistry can discover other things besides poisons, and

that it is indeed one of the stoutest allies of the law.

The desirability of the photographs also invites comment. The expert in his laboratory can look down his microscope and arrive at his decisions which may be perfectly justifiable and satisfactory from a scientific point of view. There is, however, the possibility that the judge and jury may not believe him. Demonstration may convince where scientific evidence alone will not. Seeing is believing. It is in this connexion that the photograph may be of great importance. The expert had in this case his photographs of pure atropine and the crystals obtained from the body of the victim. He was able to indicate the points of resemblance and leave the jury to decide for themselves. They were satisfied that atropine had been administered, and Dr. Eustachy was convicted.

This trial, not in other ways of much interest or importance, was a signal victory for science. Not only was the accused convicted upon the evidence of the test-tube and microscope, but that evidence was capable of demonstration to the satisfaction of the court. A vital principle is here, involved. The judge and jury and not the expert witness have to try the prisoner. It is the duty and the aim of the expert to place before the court his evidence in a form that the court can best understand.

As a further illustration of this principle there is the interesting case tried ,in New York in 1893 Avhen the court was turned into a chemical laboratory, and experiments were performed before the judge and jury. It was a strange scene. There was a long table in full view of the judge and jury. Upon it were arranged testtubes and bottles full of chemicals. Behind it,was Dr. Victor C. Vaughan, a chemist and professor of toxicology in the University of Michigan. In the dock was Robert Buchanan, a doctor of medicine, on trial for his life. The atmosphere of the court was tense. The experts for the prosecution had been a little too confident in giving their evidence regarding the reactions for morphine, the alleged poison used.

O’Sullivan, the brilliant advocate for the defence, was cross-examining the experts. He believed that morphine was detected by means of certain colour reactions. The experts agreed. They were satisfied that the tests they had employed distinglished morphine from every other substance. The experts expressed themselves satisfied. O’Sullivan now turned to Dr. Vaughan who had been retained for the defence and questioned him regarding tests which gave similar results for morphine and for substances which might be found in human remains. Every eye was turned on the toxicologist who for answer began to work with his test-tubes and chemicals. He tested first some ptomaine material mixed with morphine, and then the same material without the morphine. At least one test, and that an important one which the prosecution admitted having used, showed the same result. He held the two test-tubes up; both contained deep red solutions. There was an excited buzz in court, and O’Sullivan triumphantly sat down. It was a brilliant piece of advocacy which badly shook the prosecution’s case, but it was in reality more dramatic than definitely convincing. It is quite true that human remains contain substances which give some reactions similar to alkaloids like morphine. In 1893 they might have been confused by a. careless operator. Under the subtle cross-examination of a clever advocate the experts’ evidence appeared unsatisfactory, but they had not been unwise enougii to rely upon one or even two tests, or at least they succeeded in satisfying the judge that they had, in fact, discovered morphine in the body, and, unfortunately for the prisoner, atropine as well. This astute criminal had administered some atropine with the morphine in order to mask the symptoms of morphine poisoning. The use of a small quantity of atropine prevents, dilation of the pupils which is a characteristic feature of poisoning by this alkaloid. The ruse at first succeeded. The doctors returned the cause of death as cerebral haemorrhage. The body of Mrs. BuchanaS was later, as the result of rumour, exhumed and an autopsy performed. Dr. Buchanan was convicted upon evidence not in all respects satisfactory. There was little doubt of his guilt, but one remains as to whether the evidence upon which he was convicted was not defective. It is, I think, unquestionable that the prosecution demonstrated the existence of both morphine and atropine in the body. It was vital to their case that not one but both were present, but their evidence left something to be desired. The defence was brilliantly conducted with a view to upsetting the expert evidence, so that it probably appears weaker than, in fact, it was. The evidence of the accused himself was very unsatisfactory, and undoubtedly contributed to the verdict being given against him; but he should have had, in the opinion of many, the benefit of the doubt. (To be continued).