I buy bags of ice – not being sufficiently well-off to afford a contraption that makes it, but being sufficiently fond of taking my whisky on the rocks that I can’t keep up by making it in trays – and a thought often tickles me when I reach into one.

Sometimes, you see, I drop a chunk of ice on the floor, and at that point, of course, it’s useless. I don’t want to pick it up and drop it in my glass, and it will melt into a puddle of water when I chuck it in the fridge. And the thought is: what I bought was a transient state of matter. Most times at the supermarket, you buy stuff – even if what you’re really buying is some chemical energy that you’ll process once you eat it rather than some immutable gobs of matter. But with ice, you specifically buy the state the matter is in.

This thought can appear to be lousy with resonances and heady with import when you are topping up your ice for a second glass of whisky, which coincidentally is when you’re most likely to drop some ice cubes on the floor.