Robert Jones

According to Webster’s New Collegiate Dictionary, a poison is “a substance that through its chemical action usually kills, injures or impairs an organism” or “a substance that inhibits the activity of another substance or the course of a reaction or process.”

Since there are many types of poisons, only a few of those commonly encountered in novels have room for mention here. For the same reason, acute (relatively quick-acting) poisoning rather than chronic (relatively prolonged) poisoning will be addressed. Many novels and films involved arsenic, cyanide or strychnine. In the film, ARSENIC AND OLD LACE, a pair of spinster aunts murder lonely old men by poisoning them with all three – a glass of home-made elderberry wine laced with arsenic, cyanide and “just a pinch” of strychnine.

Since pathologists now have the ability to detect most poisons, poisoning is no longer the preferred murder method du jour; but there are still enough poisonings to keep pathologists busy. There is no one-test-reveals-all detection system, and pathologists must determine for which poisons they should test. To do this, they evaluate clues that suggest what poison or poisons are involved and how they were administered.

ARSENIC

is a level five (the next to highest, extremely toxic, level) toxin; and it affects the digestive system. Its most common form is arsenic trioxide, a white powder. Other forms include arsenous oxide and arsenic trihydride. Arsenic fumes often have a garlic odor.

Note that a character in your novel who sips a cocktail laced with arsenic should not gasp the words, “You dirty rat,” drop immediately to the floor and neatly expire. Symptoms of arsenic poisoning primarily include severe gastric distress. Other symptoms include esophageal pain, vomiting blood, diarrhea and falling blood pressure. These are often followed by convulsions and coma, and death is usually the final result of circulatory failure.

The symptoms begin after about 30 minutes and death might follow within a few hours but might not occur for some 24 hours. If a victim dies quickly, an autopsy will reveal only an inflamed stomach and perhaps traces of the poison in the digestive tract. Red blood cells will be destroyed, and skin might take on a yellow cast. If death is delayed for several days, arsenic may also be found in the liver and kidneys.

Since arsenic is found in common household items, notably pesticides, it has been a convenient means of murder. Although it is usually swallowed, it can also be inhaled as dust or as arsine gas. Inhalation of arsenic, however, is usually associated with industrial environments. An interesting property of arsenic, although of no concern to victims of acute poisoning, is that it is carcinogenic.

CYANIDE

is a level six (the highest, supertoxic, level) toxin; and it interferes with the absorption of oxygen by the body’s cells. Its most common forms are potassium cyanide, sodium cyanide and hydrogen cyanide. Hydrogen cyanide is also known as prussic acid and hydro cyanic acid. Cyanide involved in television shows is often detected by a bitter almond odor. In reality, it does not always have a detectable odor. Also, some persons are, for genetic reasons, unable to detect the odor. Could these facts be clues in someone’s story? Speaking of clues, note that some burning plastics and fabricated fibers release cyanide gas. Many fires also produce carbon monoxide.

Since cyanide interferes with body-cell absorption of oxygen, it does most harm to the heart and brain, which demand a large amount of oxygen. Although ingesting and absorbing cyanide through the skin can also be toxic, breathing it causes the greatest harm. During WWII, Nazis used hydrogen cyanide in some of their gas chambers. Also, some of our states used it for executions before lethal injections were initiated. Readers might also recall that, in 1973, someone in Chicago laced Extra-Strength Tylenol with cyanide, which killed several persons. Also, in 1978, some 900 cult members at Jonestown, Guyana drank grape-flavored Flavor-Aid laced with cyanide.

In addition to murdering others, cyanide has also been used by many persons to kill themselves. Among the names of those you might recognize are Eva Braun, Delphine Delamare, Hermann, Goering, Heinrich Himmler, Adolph Hitler (cyanide and gunshot), Erwin Rommel and Alan Turing. In addition, of course, are myriad fictional spies who carry cyanide suicide pills to swallow if they are captured. Your cocktail-sipping characters won’t fall immediately to the floor and die after having sampled a cyanide-laced cocktail either, especially if it follows a full meal. A swallowed, lethal dose can produce convulsions, which can be followed by death, but usually only after some four to twelve hours. Sniffing a toxic dose of cyanide in the form of a gas, however, can cause immediate unconsciousness, convulsions and death within fifteen minutes. In fact, hydrogen cyanide, in high concentrations, is known as one of the “one whiff” knockdown gases.