On Christmas Day 1976 I kissed 500 women. All of them were over 70 and institutionalised, and one was either dead or killed by my kiss.

I was a houseman, working in the Eastern General in Edinburgh, close to the city’s inadequate sewerage works. The hospital was built in 1906 by Leith Parish Council as both a poor house and hospital. It’s now demolished, a site beside the sea for luxury flats.

By 1976 the poor house had become a geriatric hospital, full to the brim with the decrepit and the demented housed in Nightingale wards. It must have been a tradition for the youngest male doctor to get dressed as Father Christmas, scarlet red with a hat and white beard, and tour the geriatric hospital. It certainly wasn’t an idea that occurred to me, or perhaps it was—memory is so fickle.

Anyway I went about it with gusto. I ho hoed and moved rapidly through the female wards kissing everybody with enthusiasm. I probably cracked jokes, bad ones no doubt. I can’t remember if I was distributing presents. Perhaps my kiss was the present. Some of the women may have been pleased. Some were probably revolted. I kissed on regardless. Probably I was efficiently spreading infection.

I can’t remember any men. But in those poor houses turned geriatric hospitals gender was far from clear. Perhaps I kissed men too.

What I do remember clearly is after finishing my kissing round I was called back to pronounce a woman dead. What I don’t know is whether she was dead when I kissed her or whether my kiss killed her. And if my kiss killed her did she die joyous or appalled?

Richard Smith was the editor of the BMJ until 2004 and is director of the United Health Group’s chronic disease initiative.