An interesting fact, but not much of a quiz question IMHO. I mean ... what else could it be?
Not only that, but Bell was merely copying a device that had been invented seven years earlier, by someone else entirely.
A better quiz question (IMHO) would be to ask what was invented in 1874 by the appropriately–named French polymath scientist Gustave Trouvé. Trouvé developed a hand–held device for locating and extracting metal objects such as bullets from human patients.
It was Trouvé's invention that inspired Alexander Graham Bell to develop a similar device, seven years later, in an attempt to locate the bullet that was lodged in the chest of President Garfield. The metal detector worked correctly, but the attempt was unsuccessful because the device was confused by the metal coil springs in the bed that Garfield was lying on.
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