Daniel Engber writes in Who Will Debunk The Debunkers?:
Popeye loved his leafy greens and used them to obtain his super strength, Arbesman’s book explained, because the cartoon’s creators knew that spinach has a lot of iron. Indeed, the character would be a major evangelist for spinach in the 1930s, and it’s said he helped increase the green’s consumption in the U.S. by one-third. But this “fact” about the iron content of spinach was already on the verge of being obsolete, Arbesman said: In 1937, scientists realized that the original measurement of the iron in 100 grams of spinach — 35 milligrams — was off by a factor of 10. That’s because a German chemist named Erich von Wolff had misplaced a decimal point in his notebook back in 1870, and the goof persisted in the literature for more than half a century.
All these tellings and retellings miss one important fact: The story of the spinach myth is itself apocryphal. It’s true that spinach isn’t really all that useful as a source of iron, and it’s true that people used to think it was. But all the rest is false: No one moved a decimal point in 1870; no mistake in data entry spurred Popeye to devote himself to spinach; no misguided rules of eating were implanted by the sailor strip.
Is it true that the story that Arbesman and other tell about how the misplacement of a decimal point by Erich von Wolff lead to a popular misconception about the iron content of spinach is false?