The 20th president of the US, in office just four months, had been shot on the morning of July 2, 1881, by Charles Guiteau, an unhinged wannabe diplomat. Garfield was whisked back to a hot and rat-infested White House and put in the hands of the medical profession. By that evening an estimated 15 doctors had examined his wound, poking about with probes and fingers. Their instruments, never mind their hands, were not sterile. Why should they be? Everyone knew that the new germ theory was nonsense. For all their pokings, they couldn't find the bullet.
Weeks past, the doctors squabbled, the president's wound became infected, and the whole country was swept up in the drama. One newspaper interviewed Simon Newcomb of Baltimore, who had invented a primitive metal detector.
The article caught the eye of Alexander Graham Bell, he of telephone fame.
He realised he could improve on Newcomb's work and that together they might track down the president's bullet. All their trials were successful, even locating bullets lodged inside civil-war veterans who had volunteered to help.
Understandably Bell and Newcomb thought they had the answer and on July 26 they went to save the president. Alas, their machine hummed, indicating the presence of metal, wherever the pair put it on Garfield's body. Puzzled they went away and ran more tests. Again their device worked, but again, on August 1, it failed on the president.
Bell went home and gave up. Six weeks later Garfield died. The bullet was found to have lodged in a cyst near the spine and the autopsy concluded that the president would have survived if the medical men had let him alone. His assassin even argued in court that the doctors were the real murderers. And what of the metal detector? It eventually emerged that Garfield had been lying on a new-fangled bed, one of the very first of its kind in the country. A bed with metal springs.