This article was first published in聽
鈥淲hen a doctor does go wrong, he is the first of criminals. He has nerve and he has knowledge. Palmer and Pritchard were among the heads of their profession.鈥
That鈥檚 Sherlock Holmes commenting on his confrontation with the murderous Dr. Grimesby Roylott in The Adventure of the Speckled Band. Drs. Palmer and Pritchard were not fictional characters. They were real-life murderers whose trial in the 19th century gripped the attention of the public, not only because of their horrific crimes but because of the means used to carry them out. Their weapons were not guns or knives, but antimony, aconite and strychnine. They were poisoners.
Dr. Edward Pritchard was a former ship鈥檚 surgeon who settled in Glasgow with his Scottish wife, Mary Taylor. The couple seemed to live happily until Mary became sick with constant bouts of vomiting. Her mother, Jane, arrived to take care of her and soon became sick as well, quickly succumbing to her illness. A short while later Mary also died.
That鈥檚 when the authorities received an anonymous letter, believed to be from a physician neighbour, that cast doubt on the deaths being natural. A post-mortem on Mary鈥檚 body was performed and a residue of antimony was detected in her liver, prompting the exhumation of her mother鈥檚 body. Antimony was detected here as well, along with traces of aconite.
Chemical analysis of Battey鈥檚 Solution, an opium-based sedative that Jane had been taking, was found to contain both antimony and aconite. Antimony was also detected in a tapioca pudding that Pritchard had prepared for his wife. That was enough for Pritchard to be convicted of murder. The motive? Pritchard had been having an affair with a 15-year-old servant girl whom he had promised to marry in the event of his wife鈥檚 demise.
In the 19th century, both antimony compounds and aconite were used as medicine and were readily available to physicians. Stibnite, a naturally occurring ore of antimony sulphide, was known to the ancient Egyptians who used it as eyeliner, and the Greeks, noting its ability to cause vomiting, used it to 鈥渃leanse the body of impurities.鈥
In 1631, Dutch chemist Adrian de Mynsicht combined stibnite with potassium tartrate found in wine sediment to produce antimony potassium tartrate. Known as 鈥渢artar emetic,鈥 this would become a standard item in many a doctor鈥檚 bag. It was believed that the powerful vomiting and sweating brought on by tartar emetic would purge the body of disease. It did not do that, but a high enough dose would purge a body of life. And as Pritchard knew, it could do that even in small doses as long as it was given regularly.
Pritchard was also familiar with aconite in the form of a powder made by grinding the root of the aconitum plant, better known as wolfsbane or monkshood. Like antimony, this was also known to the ancients. The 1st-century Greek physician Dioscorides described mixing the plant with meat to kill wolves, hence the name wolfsbane.
鈥淢onkshood鈥 stems from the similarity of the plant鈥檚 flowers to the hood worn by monks. All parts of the plant contain the alkaloid aconitine, a potent neurotoxin that depending on the dose can cause vomiting, sweating, a sensation of burning or a lethal irregular heartbeat. In ancient Greece and India, extracts of the plant were used to tip poison arrows, and the Romans referred to aconite as mother-in-law鈥檚 poison, a term that could have been applied to its use by Pritchard as well. A Chinese manuscript dating to the 2nd century BCE describes aconite as a vicious poison, but also mentions that鈥 a good doctor finds it useful.鈥
We next hear of aconite as medicine in the 18th century from Viennese physician Anton von Stoerk, who after experimenting on himself found that a small dose of aconite can cause sweating. This led him to conclude that it was therefore useful in expelling diseased matter from the body and recommended it for fever, rheumatism and gout. As Pritchard knew from his medical training, aconite was also useful in expelling life from a body.
Charles Dickens called Dr. William Palmer 鈥渢he greatest villain that ever stood in the Old Bailey.鈥 Soon after launching his medical career in 1846, Palmer became more interested in ponies than in patients. He began to pile up debts but found a way out after going to the races with a friend, John Cook. Palmer lost, but Cook had a huge win. The two went to celebrate, and Palmer offered his friend a drink of brandy that Cook complained burned his throat. In the following days, Cook took ill and was looked after by his doctor friend who prepared 鈥渃uring broths鈥 for him. Cook鈥檚 health fluctuated, first improving, then worsening after he ate.
In the meantime, Palmer offered to pick up his winnings, which he then did. A couple of days later, Cook died in a fit of severe convulsions. Cook鈥檚 stepfather became suspicious when Palmer told him that the ticket to cash his son鈥檚 winnings had been lost and insisted on a post-mortem. As Cook鈥檚 physician, Palmer was present at the autopsy and allegedly tampered with the samples taken from the deceased man鈥檚 stomach. No evidence of any toxic substance was found.
Nevertheless, at the coroner鈥檚 inquest, Dr. Alfred Swaine Taylor, a highly respected toxicologist, testified that Cook鈥檚 symptoms were typical of strychnine poisoning. Strychnine occurs in the seeds of the Strychnos nux-vomica tree and is known to interfere with the action of glycine, an inhibitory neurotransmitter. When glycine binds to nerve endings, it prevents the nerve from firing, meaning that interference with its activity causes excessive stimulation. This can lead to spasm of the respiratory muscles resulting in death by asphyxiation. In small doses, strychnine was used by 19th-century physicians to pep up lethargic patients, so there is no doubt that Palmer was aware of its properties.
During the inquest, information came to light suggesting a sordid past for the doctor. Four of his five children had died in infancy and a maid testified that Palmer had said he could not support them. His wife and brother also died under mysterious circumstances after he had taken out life insurance for them. Taylor鈥檚 testimony and the circumstantial evidence based on the death of his family members was enough to convict Palmer despite no strychnine actually having been detected.
Both Pritchard and Palmer were hanged for their crimes, with Pritchard鈥檚 hanging being the last public execution in Scotland, witnessed by thousands. Sir Arthur Conan Doyle, the creator of Sherlock Holmes, was obviously familiar with the famous cases, but being a physician himself should have known that neither Pritchard nor Palmer were 鈥渁t the head of their profession.鈥 One of the rare times he had Holmes make a mistake.