Spitting is the short answer. In China it seems to be unacceptable to swallow your own spit, so people freely dispense with it anywhere and everywhere. So also, surpisingly, in Norway. When walking a Norwegian street, you need to step carefully, for the footpath is spattered with green and yellow gobs – and that’s just the fresh ones. When I first encountered this, I wondered: does everyone have sinus infections here? Is it the water? The climate? The brown cheese – myseost?

No, I finally found out: it’s the snus. Not quite chewing tobacco, snus is a small satchel of finely cut tobacco that you stick in your mouth, preferably on a gum and let the nicotine seep into your system that way.

One of the more endearing features of Scandinavia (they love it in Sweden too):

Needless to say, it produces big yellow-green balls of snot to spit out on the footpath.

However, China has now turned its back on this refined cultural practice. Nothing like a threatening epidemic (SARS) to change collective behaviour. Since 2002 spitting has been banned in public in China, with fines and the penalty of cleaning up your own spit, so much so that ‘many public health workers feel their work has become easier, with fewer phlegm marks found in most roads‘.

Although I must admit that in the odd corner you can come across a ready-made somewhat mucus-like skating area.