Chemical History

The Crooked House

Chemical Institute of Canada — Sun, 27 Nov 2011 02:02:56 GMT

Agatha Christie's "The Crooked House" is a great story. The plot revolves around an elderly tycoon who requires daily insulin shots. He also suffers from glaucoma for which he has been prescribed eyedrops. Everything is fine until someone in the "Crooked House" switches the eyedrops with the insulin. Murder most foul!

Does the chemistry make sense? Let's do a little detective work of our own. As clearly stated in the novel, the eyedrops contain physostigmine, a substance introduced in the late 1800's for the treatment of excess pressure in the eyeball, a symptom characteristic of glaucoma. Physostigmine, or "eserine" as it is also known, opens up the tiny ducts through which excess fluid is normally expelled from the eye. Could this drug really be lethal if injected into the bloodstream?

Physostigmine has a long and interesting history. It is the active ingredient in the "ordeal" bean, found in the Calabar region of Nigeria. Why the term "ordeal" bean? Because it was traditionally used by certain tribes as a test of guilt. Someone suspected of having committed a crime was forced to swallow a handful of beans. If he died, he was guilty. Unfortunately, he probably died even if he wasn't guilty. Physostigmine is known to enhance the activity of acetylcholine, a chemical essential for the proper functioning of our nervous system. It does this by inactivating an enzyme called cholinesterase which normally degrades acetylcholine after it has done its job. The result is a buildup of acetylcholine which can lead to paralysis of the respiratory muscles and death. Maybe if the accused were really confident of his innocence, he would eat the beans quickly, vomit and survive!

By the late 1800's, physostigmine had been isolated from the Calabar bean and was widely used in the form of eyedrops for the treatment of glaucoma. The amount needed on a daily basis was very little, but there certainly would have been enough active ingredient in a bottle to kill if directly injected with a syringe. Had a physician arrived soon enough, the effects probably could have been reversed. Atropine, found in the belladonna plant, can block the receptor sites on nerve cells which are normally activated by acetylcholine. This antidote was routinely carried by the doctors of the day, not necessarily to deal with phytostigmine poisoning, but because atropine is a potent heart stimulant. But if the victim had lived, there would have been no murder, and no story. Who needs a story though, when real life poisonings may be stranger than fiction!

Cyanoacrylate Glue, aka “Super Glue” aka “Krazy Glue

Chemical Institute of Canada — Mon, 09 May 2011 03:10:59 GMT

Harry Wesley Coover Jr., the inventor of “Super Glue” recently passed away at the age of 94. Super Glue is an adhesive with extraordinary bonding capabilities – just a couple of drops of the liquid and you can virtually glue anything together permanently! Remember the construction worker holding onto his helmet which is attached only by a drop of glue to a beam? A bit of creative marketing here unless the worker had super strength in his arms. But the glue really could hold that kind of weight. It can even be used to glue skin together instead of sutures!

As with many inventions, superglue was an accidental discovery. During WWII, Dr. Coover and colleagues were trying to find a way to use clear plastic to make gun sights for weapons out of a particular kind of plastic known as polycyanoacrylate. However, Coover found cyanoacrylates too sticky to work with and discounted them. Later, in 1941, while working for the Eastman Kodak Company, Coover found that the stickiness of cyanoacrylates came in handy in the manufacture of plastic canopies for jet planes. Coover and Kodak subsequently refined the substance and commercialized it as a glue. The chemistry here is fascinating. The tube of Super Glue doesn’t actually contain glue. It contains a chemical, usually ethylcyanoacrylate, that forms the glue once it comes into contact with moisture in the air. It is water that initiates a reaction by which the small ethylcyanoacrylate molecules join together to form polyethylcyanoacrylate which is the actual glue. This is also the reason why it can be frustrating to keep a tube of cyanoacrylate glue from hardening. Once it is opened, moisture inevitably enters and converts the monomers to a hard polymer. High humidity causes the glue to set quickly, explaining why it is harder to keep an open tube from clogging up in Miami than in Denver.

In 1977 another amazing property of cyanoacrylate glue was discovered. It could reveal latent fingerprints! Trace evidence examiner Fuseo Matsumara from the National Police Agency of Japan noticed his own fingerprints developing on microscope slides while he used cyanoacrylate glue to mount hairs from a taxi driver murder case. Matsumara later relayed this information to his colleague Masato Soba, who developed the cyanoacrylate fuming method.

So how are latent fingerprints recovered with superglue fumes? Fingerprints are composed of several chemicals exuded through the pores in the fingertips and are left on virtually every object touched. The primary component of latent fingerprints is sweat, which is mostly water, and will dry out after a short period of time. The other components are mainly solid and will remain on the surface for a much longer period of time. These solids include organic compounds like amino acids, glucose, lactic acid, peptides, and inorganic chemicals such as potassium and sodium salts. The item featuring the invisible fingerprints is placed inside a compartment where super glue is heated to the point of vaporization (54-56 C). Once the superglue vapor interacts with the chemicals left behind by the suspect, a visible, hard, white substance is formed on the ridges of the print. At this point, the crime lab technician can photograph and analyze the print. Unfortunately, the superglue fuming method isn’t that simple and does come with caveats. The process can take up to five hours, so investigators commonly use accelerating methods to alter the heating process or the atmospheric pressure inside the container. And once the fingerprints have been visualized, the fumes must be vented out of the container by high-powered fans because superglue fumes are highly irritating and flammable. Furthermore, its combustion can produce lethal amounts of cyanide gas. Nevertheless, superglue has helped put many criminals away, while exonerating some innocents. Just a year ago, in 1910 President Obama honoured Dr. Coover with the National Medal of Science.

Happy Birthday Harry Houdini!

Chemical Institute of Canada — Fri, 25 Mar 2011 01:06:06 GMT

March 24, 1876 was a historic day both in the world of science and the world of entertainment. That’s when a man who would become a legend in both entered this world. Born as Erich Weiss, he would make his mark as Harry Houdini. I’m into magic and I’m into science, so I’m obviously a fan. But I have another reason to be interested in the most famous magician of all time. Harry Houdini’s name will forever be linked with McGill University!

As recorded in numerous biographies, it was J. Gordon Whitehead, a McGill student, who delivered the blow that led to the death of the man whose name has become synonymous with magic. It was on October 22, 1926 during a visit to Houdini’s dressing room at the Princess theatre in Montreal, that Whitehead asked about the magician’s claim of being able to withstand any punch to the stomach. Somewhat distracted, Houdini grunted a yes, at which point Whitehead let loose with a flurry of punches. Although he was an in excellent physical shape, as execution of his legendary escapes demanded, Harry had not flexed his stomach muscles properly for the onslaught. The man who had pulled off stunning escapes from straight jackets, handcuffs and sealed coffins could not escape the effects of a ruptured appendix. Still, he managed to travel to Detroit, his next venue, where he had to be hospitalized, finally succumbing on the most appropriate day for a magician to make his final exit, Halloween!

While the Whitehead connection has been well publicized, there is another Houdini link to McGill that is virtually unknown. The Osler Library of Medicine at the university is home to a historic pamphlet, “Account of a new anesthetic agent, as a substitute for sulphuric ether in surgery and midwifery,” authored by Scottish physician James Young Simpson and dated November 12, 1847. One of only two surviving such pamphlets, it records the first-ever use of chloroform as an anesthetic!

James Simpson was a Professor of Midwifery, yes, you read that correctly, at Edinburgh University. He was dedicated to easing labour pains for women, and in 1846 was thrilled to hear of William Morton’s successful induction of ether anesthesia at Massachusetts General Hospital in Boston. Within months Simpson was experimenting with ether, sometimes supplemented with “ergot of rye.” Ergot is a fungus that produces lysergic acid, a chemical relative of LSD. That must have added another dimension to labour! But ether sometimes caused bronchial irritation and had a disagreeable and persistent smell to boot. So Simpson decided to look for an ether substitute. “I have tried upon myself and others the inhalation of different other volatile fluids,” he reported, “with the hope that some of them might be found to possess the advantages of ether, without its disadvantages.”

Simpson’s experiments were not the epitome of science. He and his friends filled glass tumblers with different volatile liquids, inhaled the vapours, and waited for something to happen. And with chloroform it did! As an observer described, “unwarranted hilarity seized the party, they became very bright-eyed, very happy and very loquacious…a moment more, and then all was quiet…a chorus of snores soon filled the air..on awakening, they expressed delight with this new agent, and its inhalation was repeated many times that night until the supply of chloroform was exhausted.” “This is far stronger and better than ether,” Simpson concluded.

Indeed, far less chloroform than ether was needed to produce an anesthetic effect, its action was more rapid, it was pleasant smelling, and required no special inhaler for administration. A chloroform moistened handkerchief held over the nose and mouth did the trick! Unlike ether, chloroform was not flammable, a decided advantage in days when surgery was often performed by candlelight in rooms heated with a fireplace. An impressed Simpson immediately began to use chloroform in his obstetrics practice. The first mother who gave birth under chloroform was so thankful for the pain-free delivery that she named her baby Anaesthesia!

The introduction of chloroform in childbirth was not without controversy. Clergymen objected, pointing out that God had told Eve that “in sorrow shalth though bring forth children.” Simpson cleverly retorted with the biblical account of God having cast a deep sleep upon Adam before removing his rib to create Eve. God, he claimed, was obviously in favour of anesthesia. There were safety concerns as well, especially after fifteen year old Hannah Greener died during a procedure to remove an in-grown toenail. But when Queen Victoria’s personal physician, Dr. John Snow, administered chloroform to her highness as she gave birth to Prince Leopold in 1857, the chloroform issue was settled. Surely if chloroform was good enough for the Queen, it was good enough for all. It didn’t take long for chloroform to become the most fashionable anesthetic in England. And magicians took note!

Conjurers are clever performers, always looking to add a bit of novelty to an act. And for “Dr. Lynn,” a travelling magician in America, that novelty was chloroform. His famous illusion was “Paligenesia,” in which an apparently chloroformed man was cut apart and then pieced back together. The secret to the illusion was “black art.” Assistants dressed in black worked against a black background, “cutting off” limbs by masking them with a black cloth. The supposed use of chloroform just added a little theatre to the proceedings. Onlookers were amazed, especially young Erich Weiss, who was absolutely mesmerized. Then and there he decided that his destiny was the stage.

Years later, Erich, having taken the name Houdini, bought the illusion from Lynn’s son and presented it himself. Familiarity with black art came in especially handy when Houdini launched a second career, exposing the methods fake mediums used to convince the gullible that they were communicating with the spirit world. Trumpets floated in mid air and “ectoplasm” appeared in the darkness of the séance room, often through the magic of black art.

To further his campaign for critical thinking, whenever he performed in a city with a university, Houdini would ask to speak to the students about the importance of arriving at conclusions based on evidence, not on hearsay or anecdote. His last such lecture, just days before his death, was delivered at McGill in the student union building, now the McCord Museum. That museum, I think, should have a permanent Houdini display, perhaps even including the original chloroform pamphlet that was so instrumental in launching the career of one of the greatest entertainers and promoters of critical thinking the world has ever seen.