I just finished reading Below Stairs by Margaret Powell, her memoir of working as a kitchen maid in prewar England (it is one of the sources for Upstairs, Downstairs and Downton Abbey). Chapter 15 contains this interesting paragraph:
"Another pet hate was cleaning the copper saucepans. Every time they were used they got filthy. All the bright polish would be tarnished after every meal. They had to be cleaned with a horrible mixture of silver sand, salt, vinegar, and a little flour. You mixed all this into a paste and then rubbed it on with your bare hands. You couldn't put it on with rags because you couldn't get the pressure that way, you dug your hand into the tin where you had previously mixed it all up and you rubbed it on the copper outside. It was a foul job. Every morning I had to do it. Mind you they looked lovely when I'd done them, they used to hang all along the wall in the kitchen, right from the very tiniest little saucepan, which didn't hold more than a teacup full, to the most enormous one in which you could put three Christmas puddings side by side. And there was a big fish-kettle as well. I used to get so miserable sometimes that I used to wish that they'd all get ptomaine poisoning from them. I was always being told that if I didn't clean them properly they'd get ptomaine poisoning. If they had they might have changed their saucepans."
This would have been in the twenties or early thirties. This notion of ptomaine poisoning of all things to get from a copper pan is a new one to me - has anyone else ever encountered it?