Silent Witnesses

by Nigel McCrery

  Sources show that ancient civilizations were aware of a variety of poisons and their effects. There is evidence that as far back as 4500 BC the Sumerians had knowledge of a number of poisons. A Sumerian tablet discovered in 1850 documents the use of poisons as a clandestine way to rid oneself of an enemy. And in Egypt in 3000 BC the first pharaoh, Menes, is reputed to have conducted research into many varieties of poisonous plants and their properties. The ancient Egyptians also possessed knowledge of how to create and refine particular poisons, such as how to extract cyanide from peach kernels. An ancient Egyptian text that was discovered in 1872 contains a list of poisons and their antidotes. Later, in ancient Greece, poison was employed in state executions, where the condemned would be made to drink a cup of hemlock. Famously, this was how the philosopher Socrates was put to death in 399 BC.

  Ancient Rome was a hotbed of political intrigue and power games, where seeking the permanent removal of a rival was not uncommon. By 82 BC, poisoning had become such a scourge in the empire that the dictator and constitutional reformer Lucius Cornelius Sulla found it necessary to issue the world’s first law against poisoning, the Lex Cornelia. Despite this, poisonings continued to increase, peaking in the first century AD, during the reign of the Julio-Claudian emperors. The Roman historian Tacitus writes about an infamous poisoner by the name of Locusta, who reportedly killed the emperor Claudius with a dish of poisoned mushrooms in AD 54, having been hired to do so by his fourth wife, Agrippina the Younger. The following year she was convicted for a completely unconnected poisoning, but was rescued from execution by the emperor Nero in return for her help in poisoning Claudius’s young son Britannicus.

  A bust of Lucius Cornelius Sulla, who issued Europe’s first known law against poisoning.

  And in India under the Mauryan Empire, visha kanyas (poison damsels) were supposedly used as assassins. These Mata Haris of the ancient world would flirt their way into the trust of their victim, only to mix poison in his food or drink. It was also claimed that they saturated their bodies with gradual doses of poison (to which they themselves became accustomed) and that as a result men died after licking their naked bodies. While these salacious tales are unlikely to be wholly true, they nevertheless demonstrate that poisoning was a cultural phenomenon.

  This naturally meant that people also began to concern themselves with how to deal with it. Physicians started writing the first forensic works on how to detect poisoners, such as On Poisons, a text attributed to the Indian scholar and royal adviser Chanakya, who lived between 350 and 283 BC. In the second century BC the Greek Nicander of Colophon wrote Theriaca and Alexipharmaca, the two oldest extant works on the subject of poisons, while another Greek, Dioscorides (AD 40–90), classified poisons and differentiated their origins in his medical treatise Materia Medica, which for fifteen centuries was the authoritative textbook on the subject of poisons.

  One of the most significant—and in many ways regrettable—discoveries in the history of poisoning occurred much later, in the eighth century. Jabir ibn Hayyan, sometimes known as Geber, was a prominent chemist, alchemist, astronomer, and general polymath who was born in AD 722 in the Persian city of Tus (modern-day Iran). One of the many fields in which he is credited with making advancements is the alchemical discipline of distillation and crystallization. The understanding of these everyday chemical processes helped lay the foundations for the modern-day study of chemistry, but among the substances that Geber succeeded in crystallizing was arsenic. Transformed into a colorless, odorless, and tasteless powder, it became one of the deadliest of all poisons, impossible to detect until at least ten centuries later. It would later acquire the nickname “inheritance powder,” because of its supposed application by impatient heirs.

  As a colorless and odorless powder, arsenic proved the ideal murder weapon for many centuries—and the weapon of choice for those wanting to rid themselves of a troublesome spouse or relative.

  As new poisons were developed, the interest in their use for criminal purposes grew—after all, they were an extremely convenient way of ridding yourself of an enemy while avoiding detection. Poison became a growth industry, with people soon setting up businesses selling books on the subject and even supplying poisons to the public. Some engines of state fully embraced poisoning as a method of removing problematic individuals—the Venetian Council of Ten (1310–1797), for example, was notorious for employing the practice. In fact poisoning really took hold in Italy; in the sixteenth and seventeenth century, schools of poisoners—secret societies that taught the poisoner’s art—began springing up there. A publication called Magia Naturalis (1589) by Giovanni Battista Della Porta served as a textbook for poisoners, mentioning in particular how to lace wine with a preparation known as veninum lupinum, a combination of aconite, Taxus baccata, caustic lime, arsenic, bitter almonds, powdered glass, and honey, shaped into pills.

  One of the most notorious women to be associated with poisoning in Italy was a Neapolitan by the name of Toffana di Adamo. She created an arsenic-infused solution called Acqua Toffana, which she marketed as a ladies’ cosmetic, claiming it was a “miraculous substance oozing from the tomb of St. Nicholas di Bari.” In fact, it was famous among widows for more sinister purposes than beautification. The authorities soon caught on to the scheme as a wave of husbands began suddenly to die. Toffana was caught and admitted to causing the deaths of almost 600 husbands through selling Acqua Toffana. She was strangled to death in a Naples prison in 1709.

  This was not the only instance of women using poison for murder in seventeenth-century Italy. During the 1650s there was a noted increase in the number of young, rich widows in the larger cities of Europe. Although some of them even confessed to their priests that they had murdered their husbands by poisoning them, the priests were bound by the seal of the confessional. However, the sheer number of these confessions began to alarm them. In 1659 they appealed to Pope Alexander VII for guidance. The pope took the matter very seriously and instigated an independent investigation. What his spies discovered surprised and shocked him. A group of young wives, some from among Rome’s first families, were meeting regularly at the house of Hieronyma Spara, a well-known witch and fortune-teller. She was training these women in the art of poisoning. Papal police arrested La Spara, and she and several other women were hanged. A further thirty young wives were whipped through the streets.

  Another famous case of poisoning occurred in late seventeenth-century Paris. It bears many similarities to the crimes of Toffana di Adamo and Hieronyma Spara. Two midwives, Mesdames Lavoisin and Lavigoreux, were arrested in late 1679 for teaching, instigating, and supplying poison for hundreds of murders all over France. Using their occupation as midwives—as well as a sideline they had in fortune-telling—the two women gained access to people from every social class. On their arrest, a book was found belonging to Lavoisin that contained lists of everyone who had come to her to buy poison, including highranking individuals such as Marshal de Luxemborg and Duchess De Bouillon. Their main customers were wives trying to get rid of their husbands and men trying to eliminate relatives so they could inherit their estates. The two women were tried, found guilty, had their hands cut off, and were burnt alive in February 1680. In spite of the dire repercussions for those caught, the craze for such schools of poisoning lasted well into the eighteenth century.

  Despite the frequency with which poison was used as a pitiless and covert way to kill, it was a long time before forensic techniques were used to catch the offenders. But finally, in 1751, a toxicological report was used in the murder trial of Mary Blandy, a woman accused of poisoning her father with arsenic.

  Mary was unmarried at the age of twenty-six, which for the time was very old. It seemed puzzling that she should not have a husband, since she was by all accounts sweet, attractive, and charming, and in addition would bring with her a dowry of £1,000. This ought to have made her a pleasing prospect for any man. However, her father, Francis Blandy, a prominent lawyer in Henley-on-Thames, had a
mbitions for her. He quickly chased off any suitor he felt was either not rich enough or not of high enough social standing. This seemed to be all of them.

  Eventually, though, Mary made the acquaintance of a Scottish army captain, the Hon. William Henry Cranstoun. He wasn’t a handsome man, having a pockmarked face and cross-eyes and, despite being the son of a Scottish peer, was short of money. However, Mary was smitten with him. There was, admittedly, the small matter of his already being married. But, not wanting to let a little thing like this stand in the way, he declined to mention it. This arrangement seemed to suit everyone: Francis Blandy was delighted at the thought of his daughter marrying into the aristocracy, Mary was delighted at being with the man she loved, and Cranstoun was delighted at having found a comfortable and prosperous billet.

  In due course he decided that it was time to sort out the matter of his wife. He wrote to her, requesting that she kindly deny that they had ever been married and say instead that she had only ever been his mistress. Unsurprisingly, Mrs. Cranstoun took exception to this, and then took the captain to court. The ensuing publicity around the case exposed Cranstoun’s real situation to the Blandys: he was a fortuneless army captain who simply happened to have a title. Francis Blandy was outraged and forbade Mary from ever seeing him again.

  Mary, however, would not be put off so easily. The couple began to meet in secret, aided and abetted by Mary’s mother (particularly after Cranstoun loaned her £40 to pay off a debt in London). Then, in 1749, Mary’s mother died of a sudden illness. Cranstoun himself was now in debt and pressing Mary to pay back the £40 her mother had borrowed. In the end she was forced to take out a loan herself in order to do so. All in all, things were not going well for the couple. Cranstoun began to consider how much better things would be if Mary were to come into possession of the £10,000 inheritance which she was set to receive when her father passed away. He began to concoct an unpleasant scheme. Perhaps, he suggested to Mary, some kind of potion or remedy might improve her father’s disposition so that he would be less hostile to their union. He explained that he even knew of an herbalist who could prepare such a mixture; all they would have to do was lace his food and drink with it. Mary did exactly as he asked and it was not long before Francis Blandy became violently ill, suffering stomach pains and acute nausea. He lost weight rapidly.

  The family maid, a girl called Susan Gunnel, gradually became suspicious of the circumstances surrounding his failing health. She tried some of the food that Mary had prepared for him and soon started to feel unwell herself. This seemed to confirm her suspicions, and she decided to examine the pan in which the food had been made. When she did so, she discovered a gritty white powder. This she scraped out onto a piece of paper and then took to the local apothecary for his opinion. He, however, had no way of analyzing the powder to determine what it was. Nevertheless, Susan returned home and warned Francis Blandy that his daughter was poisoning him. He promptly called Mary to his bedside and asked her whether she was indeed tampering with his food, at which she went white and fled from the room.

  In spite of this behavior, for some reason he allowed Mary to continue to make his meals. As his condition worsened, Mary called the doctor who, having previously been shown the powder by Susan, told Mary that if her father died she would be accused of murder. Mary quickly disposed of Cranstoun’s love letters and the remaining powder. A few days before her father finally succumbed, he asked to speak to Mary. Entering the bedroom, she threw herself on her knees and begged him not to curse her. He placed his hand on her head and told her that he blessed her and that he hoped God would forgive her.

  On August 14, 1751, Francis Blandy finally died. Knowing that she was already under suspicion, Mary offered the footman £500 if he would help her run away to France. He refused and she was forced to flee on her own. It wasn’t long, however, before the circumstances of Blandy’s death became common knowledge. A hue and cry went up and, despite her best efforts, Mary was captured and brought back to the village. Cranstoun also ran for France when he heard of the situation. He made it but died there in poverty a few months later.

  How we interpret Mary’s actions depends on whether we believe she knew that the powder was poisonous all along. If she didn’t know, then it is reasonable to think she fled the room when her father asked if she was poisoning him because she feared he would be angry at being administered mood-lightening powder without permission. When told by the doctor that the powder was harmful, she immediately disposed of it. If she was administering the poison in full knowledge, then it is clear she fled from guilt, continued to give her father the powder until he was dying, and then destroyed the evidence. However, it is perhaps harder for us to believe that she was totally ignorant of what was happening.

  While Mary was awaiting trial she learned that, far from her father leaving £10,000 behind, he had left less than £4,000. This was the real reason that he had not wanted her to marry; he couldn’t afford the £1,000 dowry. Since Cranstoun had been interested in Mary on account of the supposed £10,000 she stood to inherit, the sad fact is that if Francis Blandy had been more honest about his situation and explained his predicament to Mary, tragedy might well have been averted. He died for a nonexistent fortune. Perhaps that is why he found it so easy to forgive her.

  Mary was tried for murder at Oxford Assizes on March 3, 1752. The trial took only a single day. As well as the testimony of Susan Gunnel regarding the white powder she had found at the bottom of the cooking pot, a cook gave evidence that she had seen Mary throw the letters and white powder onto the kitchen fire. A postmortem had been conducted on Francis Blandy, and although his organs could not be definitively tested for arsenic (as such a test had not yet been devised), the well-preserved state of them led several doctors to suggest that arsenic poisoning was a possible cause of death. An examination of the powder that the cook saved from the fire confirmed that it was indeed arsenic. Admittedly their method for establishing this was somewhat rudimentary: they applied a red-hot poker to the sample and smelled the resulting vapor. Still, they were convinced. Mary was found guilty and hanged on April 6, 1752. Dressed all in black with her hands tied behind her back with a black ribbon, she asked the hangman not to hang her too high for the sake of decency.

  Even though medical testimony helped convict her, the reason that Mary was caught was largely because she was not careful enough to conceal what she was doing. Had the evidence of the powder not been discovered by the servants, it is unlikely that anyone could have proved that arsenic had been used to kill Francis Blandy—as we have seen, there were no reliable scientific techniques for detecting the presence of the poison. It was a German Swedish chemist called Carl Wilhelm Scheele (1742–1786) who changed that.

  Scheele was already well known in scientific circles, having discovered seven different acids (in actual fact he discovered many more than this, but always seemed to be beaten to publication by someone else, hence his nickname, “Hard Luck Scheele”). In 1775 he made the further discovery that it was possible to make an acid by heating arsenic trioxide, “white arsenic” powder, in a solution of nitric acid and zinc. This created a dangerous gas that smelled of garlic—arseniuretted hydrogen, or arsine. This discovery meant that Scheele could now perform a postmortem test to determine if someone’s stomach contained arsenic trioxide.

  The German physician Samuel Hahnemann (1755–1843) is best known for developing the system of alternative medicine known as homeopathy. However, in 1785 he also found a method of detecting the presence of arsenic that differed from that developed by Scheele. Hahnemann discovered that when sulphuretted hydrogen gas (the gas that smells like rotten eggs) is bubbled through an acidified arsenic solution, the result is a yellow deposit: arsenic trisulphide. In Hahnemann’s test a sample that was suspected of containing arsenic could therefore be tested in two simple steps. One: dissolve the sample in nitric acid. Two: bubble sulphuretted hydrogen through the solution. If a yellow sulphide appears, arsenic is present in the samp
le.

  And in 1787, Johann Daniel Metzger (1739–1805), a professor of medicine at the University of Berlin, discovered an even easier way to confirm the presence of arsenic. He found that when a suspect material was heated along with charcoal, arsenious oxide would vaporize if it were present, and that it would leave a shiny black deposit on a porcelain plate (known as an “arsenic mirror”) if you held it above the heated mixture.

  Samuel Hahnemann, who invented a simple test for the detection of arsenic and thereby paved the way for the arrest of many poisoners.

  However, while all these discoveries were obviously important steps forward, they were only really theoretically useful. As yet there was still no way to apply these tests in a practical, forensic context. This problem was solved in 1806 by Dr. Valentine Rose of the Berlin Medical Faculty. He cut up the stomach of a victim who had allegedly been poisoned with arsenic and boiled it in water. He then filtered the resulting liquid and treated it with nitric acid. This would have the simultaneous effect of ridding the mixture of any remaining traces of flesh and converting any acid in the mixture into arsenious acid. Following this, he used potassium carbonate and calcium oxide, which would turn arsenious acid to arsenic trioxide. He was then able to perform Metzger’s test to confirm the presence of arsenic—although it could have easily been detected through any one of the various means we have already mentioned.

  We now come to one of the great unsung heroes of crime detection, the chemist James Marsh (1794–1846), who eventually held the post of Ordnance Chemist at the Royal Arsenal, Woolwich, southeast London, during the 1830s. In 1829 he had worked as Michael Faraday’s assistant and had apparently shown a great deal of promise as a scientist. It was a few years after this, in 1832, that Marsh was called to test a powder found in the organs of George Bodle, an eighty-year-old man with a vast fortune of £20,000 (about £2 million today). The prosecution believed this powder was responsible for his death.