The importance of salt in our lives is reflected in our language: salary from when people were paid in salt or salt of the earth for good honest people. Everyone used to keep their everyday supply in a box, hanging on the wall of the kitchen. Apart from being an essential practical object, in Britain it also was the symbol of an orderly, comfortable and welcoming home.
Salt used to be bought in large lumps and was ground for specific uses like cooking or preserving. Of course it would tend to get damp so it made sense to hang amounts for everyday use on the wall near the fire where all the cooking went on. I love this evocation of a Tudor kitchen in Cotehele in Cornwall which clearly shows the wooden salt box to the left of the large fireplace. 
You can spot salt boxes in ceramic and enamel too and, as they were used all over Europe, they’re often marked with salt in the language of origin – like this French one. 
However, whichever the country the message a salt box gave was of hospitality and a life well lived. Proof? Read this extract from the master of social observation, Charles Dickens.
It was a very dark miserable place, very low, and very damp…The grate…was…screwed up tight, so as to hold no more than a little thin sandwich of fire. Everything was locked up; the coal-cellar, the candle-box, the salt-box, the meat-safe, were all padlocked…The pinched and meagre aspect of the place would have killed a chameleon.
Charles Dickens, Master Humphrey’s Clock, 1840-41
