Stories never fail to catch the attention of children. Here are two interesting tidbits to use in your classes.

Flatus: Beware!
Flatus is the gas generated in, or expelled from, the digestive tract, especially the stomach and intestines. More than 99% of human flatus comprises nitrogen, oxygen, hydrogen (hydrogen-consuming bacteria in the digestive tract may consume some of this to produce methane and other gases), carbon dioxide, and methane.

During World War II, US fighter pilots flew at increasing altitudes. The associated reduction in the (external) atmospheric pressure allowed the digestive gases trapped in their intestines to expand (Boyle’s law), causing very painful cramps. Foods known for their ability to produce flatus – dried beans and peas, vegetables of the cabbage family, carbonated drinks, and beer – were therefore removed from pilots’ menus.

Methane is a combustible gas (e.g., a good fuel for Bunsen burners), although it is produced by only about one-third of people in the Western world. In the early days of the space race, there was concern that the methane emitted by astronauts, if accidentally ignited, could cause an explosion within the spacecraft. No such incidents have occurred to date. However, exploding flatus has caused the accidental death of at least one surgical patient. An electrode touched to the patient’s colon ignited the hydrogen and methane it contained, also causing the surgeon to be blown back to the wall of the room.

Reproduced, with permission, from The Science Education Review, Volume 3 (2004), pp. 111-112.

The Discovery of Artificial Sweeteners: Good Luck and Bad Science?
Stephen Rowcliffe, Grange School, Santiago, Chile [email protected]

Saccharin is the world’s oldest artificial sweetener, and was discovered in 1879 by Ira Remsen and Constantin Fahlberg at Johns Hopkins University. The sodium salt of saccharin (orthobenzoyl sulfimide (C7H4NNaO3S) is about 300 times sweeter tasting than sucrose and has been of great benefit to diabetics and dieters since it first went on sale in 1907. This is because it has no calorific value, being excreted from the body, after consumption, unchanged in the urine, and yet allowing users to enjoy the sweet taste they crave.

The discovery of the sweetness of the chemical came quite by chance, when Fahlberg failed to wash his hands before dinner, after spending the day working on coal tar chemical derivatives under the supervision and guidance of Remsen, his research professor. He had spilled some chemicals on his hands during the day and, later that evening when he reached for a slice of bread, he found to his astonishment that it tasted extremely sweet. He spent a long time finding out the exact substance that had caused the sweet taste, licking various chemicals on his clothes and around the lab until he found the one responsible. He was quite lucky that he didn’t make himself seriously ill in the process!

The two scientists jointly published the discovery of saccharin in 1880. Remsen lost interest in the chemical, as he was not a believer in commercial gain through the exploitation of science, but Fahlberg was much more ambitious–and ruthless. He found a way to mass-produce the chemical and then patented it in 1884, without giving any mention to his former partner or cutting him into any of the money. Falhberg became extremely wealthy from the sale of saccharin, and Remsen was understandably extremely annoyed. He was quoted as saying of his former colleague: “Fahlberg is a scoundrel. It nauseates me to hear my name mentioned in the same breath with him.” However, he eventually overcame some of his ill-feelings for his former colleague, and was part of the group of scientists who declared the chemical safe for human consumption in 1907.

Most of our other artificial sweeteners were also discovered by chance; cyclamate, by Michael Sveda, who inadvertently rested the butt of his cigarette in a pool of chemicals on his lab bench at the University of Illinois in 1937, finding it pleasantly sweet when he returned it to his lips moments later, and aspartame in 1965 by Jim Schlatter, who was working on a cure for ulcers at the time and had accidentally smeared some of the chemical he was studying onto his fingers from a flask. When he licked his fingers to pick up a piece of paper, he discovered the taste that millions of people every year enjoy in diet soft drinks and sugar-free gum.

Possibly the most bizarre example of such an accidental discovery was due to a simple language miscommunication. Shashikant Phadnis, an overseas graduate chemistry student working for British sugar giant Tate & Lyle in 1976, misunderstood a request to test a chemical compound of sucrose and chlorine. Due to his incomplete grasp of English, he heard the word taste and gamely drank some of the chemical, the safety of which was completely unknown! Thankfully, he was unharmed, and in the process discovered yet another of our popular artificial sweeteners, the addition of chlorine having made the sucrose taste hundreds of times sweeter than normal.

The way in which these popular food additives were discovered seems incredible by today’s standards of lab health and safety, as the scientists’ lives may have been at risk from poisoning. In recent years, there has actually been some doubt as to the safety of many artificial sweeteners, with cyclamate banned in the 1970s and saccharine, in (extremely) high doses, shown to cause bladder cancer. However, they have helped many obese people to lose weight and many diabetics to keep their blood sugar levels under control, and so have undoubtedly made a significant contribution to society.

Reproduced, with permission, from The Science Education Review, Volume 3 (2004), pp. 111-112.

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