A is for Arsenic (27 page)

One very serious side effect of morphine, and therefore of heroin and codeine, is a reduction in breathing rate. This is what kills in cases of overdose or poisoning. Usually, breathing rates are carefully monitored and controlled in the body. Receptors in the body are sensitive to the amount of carbon dioxide being expelled as well as to low levels of oxygen (hypoxia). During periods of increased metabolic rate, higher levels of carbon dioxide are produced than usual. The excess carbon dioxide is converted by enzymes into carbonic acid, which lowers the pH of the blood. The body normally responds by increasing the rate and intensity of breathing to expel excess carbon dioxide and to increase the amount of oxygen entering the lungs. Opioids reduce the sensitivity of the respiratory centre (a region of the brain that controls the muscles responsible for inhalation and exhalation) to carbon dioxide, and depress the automatic activity of this region so breathing becomes slower, and may stop altogether during sleep. The lethal dose of morphine is generally taken to be between 100 and 300mg, though addicts can tolerate 10 to 20 times as much.

The symptoms of morphine poisoning (which are very similar to those of heroin or other opiates) appear within five or ten minutes after injection, or 15 to 40 minutes after ingestion. Sedation deepens rapidly into coma; the pupils contract to pinpoints and there is a substantial reduction in the rate of respiration. Death occurs from respiratory failure. By contrast, excitement and convulsions are not uncommon in codeine or heroin poisonings.

Is there an antidote?

A number of drugs have been developed to act as specific antidotes for a morphine overdose, by displacing it from the opioid receptors. Perhaps the most successful of these drugs is
naloxone, a compound developed in the 1960s, which is a pure opioid antagonist. Naloxone
⁷²
is structurally very similar to morphine, but subtle differences produce dramatically different results. The drug is administered by injection in cases of an opioid overdose, to restore normal breathing. When naloxone takes the place of morphine at opioid receptors, it does not trigger them. The effects of opioids are therefore mostly reversed, including suppression of breathing and pain relief, and this can occur within a few minutes.

Some real-life cases

The ease of obtaining morphine before 1920, and the fact that it was undetectable in cadavers until 1850, together with publicity from several high-profile cases undoubtedly means murderers have gone unpunished for their crimes in the past. Morphine and its derivatives have continued to be used as poisons in murder, even when regulations have attempted to control their distribution and forensic methods have improved to enable detection of morphine poisoning several years after the event.

Some years after
Sad Cypress
, Agatha Christie returned to morphine as a means of murder in her 1968 novel
By the Pricking of My Thumbs
, in which a series of murders occurs in a nursing home, with no apparent motive. A real-life case from 1935 may well have provided inspiration to the author.

Dorothea Waddingham was not a qualified nurse, but she was always referred to as Nurse Waddingham. She ran a care home in Nottingham with her husband; in 1935 there were three residents in the home, Louisa and Ada Baguley (a mother and daughter), and a Mrs Kemp, whose condition caused her a lot of pain and for which she was prescribed morphine. When Mrs Kemp died, Nurse Waddingham still had a considerable amount of morphine in her possession. The Baguleys, the two remaining residents, were persuaded to sign
over all their money to Nurse Waddingham in return for being looked after in the home for the rest of their lives. This turned out to be a very short period of time.

At no point did the Baguleys complain about their treatment in the home, and the pair seemed to be very happy there. However, they required a considerable amount of care in return for the relatively low rent (£3 per week
⁷³
) they were paying. The 50-year-old daughter, Ada, suffered from a degenerative disease, and her elderly mother was no longer able to care for her. Nurse Waddingham commented that ‘they would have to pay five guineas a week each for no better treatment in hospital, and that is really the proper place for them'.
⁷⁴

Ada Baguley changed her will on 4 May 1935. Eight days later her mother Louisa was dead. No suspicion was attached to the death, and Ada continued to live at the home. On 10 September a friend of Ada's, Mrs Briggs, visited her at the home and found Ada in good spirits. She invited Ada to visit her on the following Thursday, and everyone agreed to the arrangement. But the next morning Ada was found in a coma, and a doctor was called. She had been unconscious since 2 a.m., but the doctor did not arrive until midday, three hours after he had been called. By the time he arrived Ada was dead.

The doctor was not surprised at Ada's death, but he had not expected it to come so soon. He examined the body, certified that death was due to cardiovascular degeneration, and issued a death certificate. Ada Baguley's cremation was arranged for 13 September, but it did not take place. A certain level of scrutiny is applied to cremation in Britain, in case someone is attempting to destroy evidence of foul play. In 1935 a second death certificate had to be issued by another doctor, and all cremations were reviewed before going ahead. In most cases, of course, this was purely a formality. However, the Cremation Referee in Nottingham at the time, Dr Cyril Banks, also happened to be the Medical Officer of Health. He knew Nurse
Waddingham's home was not a registered nursing home, and no state registered nurse was on its staff. Banks decided to investigate Ada's death more fully, and ordered a post-mortem.

There was no indication of a natural cause of death. Ada's condition, disseminated sclerosis or ‘creeping paralysis', was progressive but not at a stage where death might be expected. Analysts were called in to see if any poison had been administered. Considerable quantities of morphine were found in the stomach, spleen, kidneys and liver. The stomach contained 2.5 grains (approximately 150mg), and the body as a whole contained more than three grains. Given the rapid metabolism of morphine in the body, the actual dose was probably much higher. In the light of these results Ada's mother Louisa Baguley's body was swiftly exhumed; it too was found to contain considerable quantities of morphine-related compounds. Nurse Waddingham was found guilty of murder, and was hanged in April 1936.

No chapter about morphine can fail to mention the most notorious real-life morphine poisoner of all, Harold Shipman. Shipman was a medical doctor who worked as a general practitioner in the north of England. Britain's most prolific serial killer, he was found guilty in January 2000 of the murder of 15 people. A subsequent enquiry investigated the deaths of more than 1,000 of Shipman's patients, and he was found responsible for between 220 and 240 of them. The true total will probably never be known, because in many of the earlier cases there was too little evidence on which to determine what really happened.

The deaths occurred over a period of 23 years, but suspicion was only aroused because Shipman attempted to forge the will of his last victim, Kathleen Grundy, in 1998. His victims were usually elderly women living alone, though he also killed some men. They were usually healthy for their age, and with no apparent wish to die. His oldest victim was 93, Ann Cooper, and
the youngest was 41-year-old Peter Lewis, who was terminally ill and whose death Shipman hastened. Most of his victims were killed with an injection of an opiate, usually diamorphine, though he sometimes used a large dose of sedatives.

Shipman was able to obtain large quantities of controlled drugs by a number of different methods. For example, in 1996 he prescribed and obtained as much as 12,000mg of diamorphine on a single occasion, in the name of a dying patient. That alone would have been sufficient to kill about 360 people. The enquiry into Shipman's murders led to significant changes in the regulation and control of certain prescription drugs such as diamorphine and morphine.

Much of the evidence against Shipman came from the examination of death certificates and medical records, as well as interviews with relatives of the deceased and work colleagues. In addition to this, nine exhumations were carried out, and post-mortem examination revealed the presence of substantial quantities of morphine. Many of Shipman's victims were cremated, and other deaths had occurred too long ago to obtain forensic evidence; after burial for more than four years morphine levels in a body cannot be reliably determined. There was no attempt to determine whether the drug used was heroin or morphine, or the quantity or method of administration. Analysis was conducted on the thigh muscle and liver where possible. Shipman had claimed many of his victims had a drug habit, but analysis of hair revealed only very low levels of morphine, consistent with individuals who had used over-the-counter medications containing codeine.

Shipman hanged himself in prison without ever revealing the total number of his victims, or his motives for killing them. In a will, dated 1979, Shipman had left everything to his wife. He had ticked the cremation box.

Agatha and morphine

The plot of
Sad Cypress
centres around two deaths caused by morphine poisoning. The prime suspect is Elinor Carlisle, a young woman hoping to marry Roddy Welman. The only
cloud on the couple's horizon is a lack of funds, but this is only a temporary set-back. The pair are both related to the wealthy Mrs Laura Welman and, as her closest relatives, they expect to inherit. Mrs Welman has recently suffered a stroke and is in poor health, so it is only a matter of time before the couple should be able to set a date for their big day. That is until Elinor receives an anonymous letter suggesting that Mary Gerrard, a pretty young companion of Mrs Welman, has been sucking up to the old lady, and the inheritance may be in jeopardy. The pair decide to visit Mrs Welman, ostensibly to see a much-loved relative, but also to protect their interests. The visit is going well until Roddy bumps into Mary Gerrard, whom he has not seen since childhood, and is bowled over by her beauty. Elinor is suddenly in danger of losing both her inheritance and her man to the same woman.

A week after the visit a telegram summons Elinor and Roddy back to Mrs Welman's house. The old lady had suffered a second stroke and was very ill. Elinor arrives at Mrs Welman's bedside in time to hear her request for a solicitor. Mrs Welman dies the following night, before the solicitor arrives. The death certificate is made out, with the death attributed to natural causes. No one is surprised at Mrs Welman's passing, but it is thought to be a little sooner than expected. The only surprise is that Mrs Welman died intestate. With no will, Mrs Welman's considerable inheritance goes to Elinor Carlisle as her closest living relative (Roddy was only related by marriage). Elinor and Roddy's marriage is called off, perhaps due to Roddy being uncomfortable at being financially reliant on his future wife, but maybe it has more to do with his infatuation with Mary Gerrard.

One month later, Elinor returns to the house to pack up her aunt's belongings. She invites Mary Gerrard and Mrs Welman's former nurse, Nurse Hopkins, to have lunch with her at the house. A plate of fish-paste sandwiches and tea is served. Nurse Hopkins then offers to help Elinor turn out Mrs Welman's clothes. While the two are busy in another room Mary Gerrard slumps down in her seat and falls asleep. An hour later Mary
cannot be woken, and is clearly very ill. A doctor is called but Mary dies shortly after he arrives.

A post-mortem examination of Mary's body reveals that she died from a rare form of morphine poisoning – foudroyante, from the French meaning ‘violent'. There are three forms of opium poisoning, as described in Alexander Blyth's book
Poisons, Their Effects and Detection
, which Agatha Christie is likely to have read. Morphine poisoning usually causes a period of excitement, followed by narcosis and coma with the symptoms appearing between 30 minutes and one hour after exposure. The foudroyante form proceeds very rapidly, yielding deep sleep within five or ten minutes and death within a few hours; the pupils remain dilated, unlike the pinpoint pupils usually seen in opioid users. A third, exceptionally rare, form of morphine poisoning leads to convulsions, but no coma.

Mary has clearly been deliberately poisoned, and Elinor immediately comes under suspicion. She had made an unfortunate comment the day Mary died. When she purchased the fish paste for the sandwiches from the village shop she said, ‘one used to be rather afraid of eating fish pastes. There have been cases of ptomaine poisoning
⁷⁵
from them, haven't there?' Despite her apparent concerns Elinor purchased two jars of fish paste. All three women at lunch had eaten fish-paste sandwiches, and all three would have been expected to be prostrate with vomiting and diarrhoea if they had suffered ‘ptomaine poisoning'. As Poirot points out, if the intention had been to imply Mary Gerrard had died of this, the choice of morphine was a poor one. Other poisons could have imitated the symptoms much more closely. Poirot even suggests that the poisoner should have chosen something like atropine, if that had been their plan.