Coroner

Somebody had to invent handwashing. That is the joke, and it is not a joke: there was a moment in history when a surgeon washing his hands before an operation rather than after it was a controversial innovation, argued about in journals, resisted by serious men. Older surgeons operated in a frock coat stiff and black with old blood, and kept it that way deliberately, because the varnish of previous patients was proof of experience. Half the people who went into a surgical ward in 1865 came out dead. Not from the knife — from what came afterwards: the wound turning, the smell, the fever, the rot. The busiest hospitals were the deadliest. The profession's explanation was bad air.

Then a surgeon in Glasgow read a French chemist's paper on fermentation, understood that the rot was made of living things rather than atmosphere, and started soaking dressings and instruments in carbolic acid — the sharp black tar derivative used for deodorising sewers. On his own accident ward, deaths after amputation dropped from roughly one in two to one in seven. He sprayed it over the operating table in a fine mist from a machine he built himself. He invented an absorbable gut ligature, so a tied blood vessel no longer needed a thread left dangling out of the body to be yanked free days later, dragging infection with it. He published the numbers. He was disbelieved for years, and the reason was simple: every measure he proposed implied that the men who had not taken it had been killing their own patients. That was exactly what it implied.

It started with a broken leg. A compound fracture — bone through the skin — was close to a death sentence then; surgeons amputated on sight rather than let it fester. Lister was a Quaker's son, raised in a house where his father ground his own lenses and made genuine improvements to the microscope, so he had grown up around the habit of looking at what other people could not see. In 1865 he dressed an eleven-year-old cart-crash victim's fracture with carbolic and left the leg on. It healed. He did it again. And again. He kept every record, and when he had eleven cases he wrote them up. He was not theorising. He was counting.

He was made a baronet, then a baron, then President of the Royal Society, and he treated Queen Victoria — he drained an abscess under the royal arm and remarked afterwards that he was the only man who had ever stuck a knife in the Queen. He died in 1912. By then the argument was over so completely that nobody remembered it had been an argument: the surgeon's own cleanliness had become the first fact in the room, before the instruments, before the diagnosis.

Forget the mortality tables and the peerage. Remember only this: he built a career on the principle that a body will tell you precisely what was done to it, if somebody is willing to look properly instead of explaining it away.