Just as diet soda’s multibillion-dollar industry stems from the unassuming Russian Jewish émigré Hyman Kirsch, so the history of artificial sweeteners is an immigrant story, one that begins in a Johns Hopkins University laboratory in 1879. Constantine Fahlberg, a “well-built, handsome, German-American,” according to an article Scientific American published years later, was working there examining the properties of coal tar. Quite by accident, he stumbled upon a chemical that would forever sweeten the course of history.

“One evening I was so interested in my laboratory,” Fahlberg told Scientific American, “that I forgot about supper until quite late, and then rushed off for a meal without stopping to wash my hands. I sat down, broke a piece of bread, and put it to my lips. It tasted unspeakably sweet. I did not ask why it was so, probably because I thought it was some cake or sweetmeat. I rinsed my mouth with water, and dried my mustache with my napkin, when, to my surprise, the napkin tasted sweeter than the bread. Then I was puzzled.”

Fahlberg quickly realized what he had stumbled upon, a byproduct of coal tar that, strangely enough, “out-sugared sugar.” After running back to the lab, he proceeded to violate several principles of scientific safety, tasting each and every chemical in order to figure out which one had accidentally found its way into his food. Stumbling upon saccharin, Fahlberg began secretly to study the compound and in time went back to Germany to set up his own manufacturing company. Soon he was selling his product worldwide.

Diet soda was certainly the furthest thing from Fahlberg’s mind; medicine was where saccharin would prove most useful, he thought, and suggested that the chemical be used in “fine wafer and other foods for invalids,” hoping it would prove “invaluable in disguising and destroying all the bitter and sour tastes in medicine without changing the character or action of the drugs.”

Fahlberg wasn’t concerned with side effects. Saccharin “has no injurious effect on the human system,” he said; “what effect has been noticed is rather beneficial than otherwise.” And soon he was looking beyond medical applications: “In the future, the new sugar will be used by druggists, physicians, bakers, confectioners, candy makers, preserve and pickle makers, liquor distillers, wine makers, and dealers in bottlers’ supplies.”

However, saccharin was always viewed a bit suspiciously; from the earliest days of its marketing and even during the First World War’s intense sugar rationing, some Americans saw the substance as a poor substitute for energy-rich sugar and perhaps even as something hazardous.

In 1937 Michael Sveda, the son of Czech immigrants and an amateur violinist and woodworker, stepped out for a cigarette after a long day of working toward his chemistry Ph.D. at the University of Illinois. Like Constantine Fahlberg before him, Sveda realized that what he was putting in his mouth was unusually sweet. He walked back in the lab for