The Third Leader: Traffic wardens - the phlegmatic view

Science is not automatically associated with manners in my randomly stocked mind. All those jostling molecules, for one thing, and a fiercely focused detachment from minor worldly matters like who goes through the laboratory door first. So we should salute an important technological advance in decorum encouragement: DNA testing for spitters.

Increasingly, traffic wardens, train staff and the like are employing "spit kits" to check DNA profiles: yesterday a Manchester motorist was convicted after repeatedly spitting at a traffic warden.

A singularly unpleasant practice, spitting, and, contrary to some opinion, never entirely socially acceptable. In the Middle Ages, you were supposed to spit under the table rather than on or across it; a French writer counselled, "Do not spit so far that you have to look for the saliva to put your foot on it."

Even so, Auden warned people threatening to invade his personal space: "I have no gun, but I can spit"; we will, though, really be in trouble if we take our lead on correct behaviour from poets. A fortiori, sports people, who still do it a lot (and sometimes, admittedly, quite skilfully: I once saw the late Billy Bremner allow for the wind).

And to a traffic warden; really. A fine body of men and women who should be treated with respect (mine's the green Peugeot, by the way). In the unlikely event that you should feel any (clearly irrational) frustration, might I recommend the cheery salute of a colleague as he passes by: "Book 'em, Danno, Murder One!" Gentle, and with the extra and private satisfaction that they won't have a clue what you're on about. Sorry? Ask your Dad.